PhD opportunities

PhD opportunities for 2015 are now open. Opportunities are being made available on a daily basis so please check this page regularly.

All our doctoral training opportunities listed below are now available through our Doctoral Training Partnerships.

Each DTP that BGS is involved with has its own flavour and research expertise. However, they all have an additional research training element over and above the research project in common.

This generally comprises activities undertaken by the whole cohort of doctoral researchers and this includes induction events and summer schools plus a range of researcher-specific training activities such as attending taught Master’s classes. The latter are usually available to all researchers across the DTP. For details about individual DTPs visit the relevant website.

The BGS is a key non-academic partner in seven of the 15 funded DTPs. In these DTPs we expect BGS-sponsored PhD students to have significant interaction with the survey during their research.

A BGS member of staff will be part of your supervision team and you will be expected to spend some of your research training at the BGS. The amount of time depends on the type of project.

The BGS has three categories of PhDs:

Opportunities for PhDs starting in 2015 are listed by science area below.

BGS hosted opportunities

Centre for Environmental Geochemistry (CEG)
Characterisation of Iron Bioavailability from African Soils

BGS Supervisor: Dr Michael Watts, Centre for Environmental Geochemistry

University Supervisor: Dr Scott Young and Professor Martin Broadley

Enquiries: For further information, please contact Dr Michael Watts

Opportunities for varied work: Fieldwork in Africa, synchrotron analyses in Canada and specialist laboratory and data interpretation training at both BGS and University of Nottingham.

Eligibility: Applicants should hold or be predicted to attain a minimum of a UK honours degree at 2:1 level or equivalent in subjects such as Environmental / Soil / Crop Science or Chemistry.

DTP: ENVISION, Lancaster University

We have recently found convincing evidence that soil dust contamination of food is an important (non-haem) dietary source of iron in several sub-Saharan African (SSA) countries. In rural Malawi, composite diet analysis of two villages and calculated food composition data were compared against iron biomarkers. Measured iron intake was greater than calculated intake, and highly correlated with Al and Ti indicating extraneous soil contamination. Less than 15% of women in the study had storage iron depletion, despite negligible intakes of haem-iron (meat source). In Ethiopia, similar observations have been cited from comparison of a dietary survey and national food composition tables and regionally from food balance sheets.

The aim of this proposal is to improve estimation of iron intake by including both intrinsic plant (IP-Fe) and extraneous soil (ES-Fe) sources as co-contributors to dietary iron. This will require the development of methods for (i) quantification of ES-Fe & IP-Fe in food sources and (ii) determination of the relative bioaccessibility of both Fe sources. For example, we shall employ Fe-57 isotopic labelling to distinguish between the two forms of Fe in test crops. Mineral/morphological characterisation of external foliar/grain dust particles will determine which soil particles are likely to be retained and contribute to ES-Fe (e.g. SEM-Dr Fields, Synchrotron-Dr Button). The bioaccessibility of IP-Fe and ES-Fe will be assessed through a simulated gut method (BARGE-UBM) using correlation with Ti, Al and V to discriminate between the two forms. This approach will determine the main source of iron present at harvest and indicate whether processing (e.g. threshing grain) reduces or increases the ES-Fe contribution. To extend the study spatially we shall characterise the parameters which control the bioavailability of ES-Fe from different soil types (Malawi).

The student will be given training in a wide range of relevant analytical and procedural methods including aspects of NERC “Most Wanted II” skills.

Year 1: Training in laboratory techniques, study design, environmental characterisation, literature review – evaluate previous work by UoN-BGS on food composition analyses. Commence pot experiments to evaluate controls on intrinsic-Fe (IP-Fe) in staple crops using Fe-57 isotopically labeled growth medium.

Year 2: Plan fieldwork in Malawi to target appropriate crops and soil classifications. Undertake fieldwork with Ministry of Agriculture (Dr Allan Chilimba) for soil and crop collection, undertake local preparation / preservation of samples and collection of surface dust for laboratory analysis (UK). Commence analyses of foodstuffs, evaluate mineralogy and chemistry of surface dust for comparison of plant (IP-Fe) and soil (ES-Fe) iron. Assess the bioaccessibility of Fe to determine the relative dietary contributions of the two forms of iron.

Year 3 to 3.5: complete laboratory analyses of field samples and pot experiments, repeat sampling by arrangement if required, data interpretation and write up for publication in peer review journals and thesis. Presentation of findings at appropriate international conference, meet with advisory group to evaluate possible implications for advising policy towards estimating iron intake in SSA.

Application procedure: Candidates wishing to apply for a BGS-hosted studentship must complete the postgraduate application form of the university where they will be registered by the deadlines indicated plus send:

  • current CV
  • names and addresses of two referees
  • personal statement written by the candidate; no longer than 1 page of A4, containing project title and detailing their reasons for applying to study a PhD and why they have selected their chosen doctoral research project

By e-mail to bufi@bgs.ac.uk

Climate and Landscape Change
Imaging the role of aggregate structure on soil hysteresis

BGS Supervisor: Barry Rawlins

University Supervisor: Prof Sacha Mooney, University of Nottingham

DTP: ENVISION, University of Nottingham

Eligibility: Applicants should hold a minimum of a UK Honours Degree at 2:1 level or equivalent in subjects including Environmental Science, Geography or Natural Sciences.

Overview: Soil aggregates, essentially the building blocks from which soils are composed, control many soil properties on which our understanding of many of the major challenges facing society depend; how much air or water the soil can hold in order to grow sufficient crops to feed ourselves. By applying X-ray computed tomography, soil researchers have recently made great improvements in understanding soil properties and processes inside aggregates, but there are several processes which are poorly understood. Specifically, it is well understood how the quantity and type of clay minerals, which expand and contract through absorbing and releasing water into their structure (thus changing their volume) influence the form of soil aggregates and connected pore structures which are fundamental to soil processes. This project will explore this fundamental question by developing new methods to examine the fine scale structure of soil aggregates by modifying their water content inside an X-ray CT scanner. By doing so it will be possible to quantify changes inside aggregates with different clay properties. This will have wider implications for managing soils to enhance functions such as water storage (plant growth/flooding) and carbon storage.

The successful candidate will be trained in the use of X-ray CT scanning, image analysis/processing and quantification (University of Nottingham). They will also receive training in the use of X-ray diffraction for clay mineral analysis and quantification (BGS laboratories). In addition, the candidate will attend several specialist training courses across the Envision group of higher education and research institutes. There will be opportunities for engagement with real soil management issues via a network of farms and landowners through supervisor Paul Newell-Price and ADAS. BGS CASE.

Application procedure: Candidates wishing to apply for a BGS-hosted studentship must complete the postgraduate application form of the university where they will be registered by the deadlines indicated plus send:

  • current CV
  • names and addresses of two referees
  • personal statement written by the candidate; no longer than 1 page of A4, containing project title and detailing their reasons for applying to study a PhD and why they have selected their chosen doctoral research project

By e-mail to bufi@bgs.ac.uk

Earth Hazards & Observatories
Early warning of landslide events using computer vision and geophysical image analysis

BGS Supervisor: Dr Jon Chambers and Dr Paul Wilkinson

University Supervisor: Dr Bai Li

DTP: ENVISION, Nottingham University

Eligibility: Applicants should hold a minimum of a UK Honours Degree at 2:1 level or equivalent in subjects such as Computer Science, Physics, Engineering, Mathematics or Natural Sciences.

Enquiries: For further details contact Dr Jonathan Chambers or Dr Bai Li

Many cuttings and embankments within the UK transport and utilities infrastructure networks were constructed more than 100 years ago and were poorly engineered. Consequently many of these structures are deteriorating and are prone to disruptive failure, particularly during periods of prolonged rainfall, as exemplified by recent extreme weather events. Considerable resources for maintenance and remediation are required, and in some cases earthwork failure can present a risk to life.

A particularly promising earthwork monitoring technology is automated time-lapse electrical resistivity tomography (ALERT), which is a geophysical ground imaging technique. Manual interpretation of ALERT data is prohibitively time consuming, particularly when near-real-time responses to changing ground conditions are required by asset owners to provide early warning of failure events. We therefore propose to develop automated approaches to analysing these images and data by applying computer vision and machine learning approaches previously developed in medical imaging and/or remote sensing for change detection - thereby providing a foundation on which to integrate the image analyse tools and geophysical instrumentation for industrial slope monitoring.

The project will focus primarily on the development of new computer vision and image analysis tools, but will require the student to work in a multidisciplinary environment with computer scientists, geophysicists, civil and engineers. The project will build upon recent collaborative research between BGS and the University of Nottingham concerned with automated edge detection within geophysical images, and will utilise geophysical imaging results from previous and ongoing infrastructure monitoring activities. The student will be given training in the processing, modelling and manipulation of geophysical data sets. The student will also have the opportunity to work with industrial partners (i.e. Network Rail) to ensure that monitoring solutions developed during the project are tailored to the requirements of potential end-users and beneficiaries.

Application procedure: Candidates wishing to apply for a BGS-hosted studentship must complete the postgraduate application form of the university where they will be registered by the deadlines indicated plus send:

  • current CV
  • names and addresses of two referees
  • personal statement written by the candidate; no longer than 1 page of A4, containing project title and detailing their reasons for applying to study a PhD and why they have selected their chosen doctoral research project

By e-mail to bufi@bgs.ac.uk

Engineering Geology
New geophysical approaches for monitoring safety-critical slopes

BGS Supervisor: Dr Paul Wilkinson and Dr Jon Chambers, Engineering Geology

University Supervisor: Professor Andrew Binley

DTP: ENVISION, Lancaster University

Engineered hydraulic barriers, such as canal embankments, reservoir and tailings dams, are increasingly susceptible to catastrophic failure due to changes in climatic conditions and land use. Thousands of miles of ageing embankments, flood defences and dams need regular appraisals to assess operational safety. Currently responsive maintenance relies on visible changes in earthwork condition such as subsidence and deformation, which often only manifest themselves very close to an imminent failure. There is a clear need for new technological solutions to provide earlier warning of potential failures and to monitor the susceptibility of damage over large areas; for example, Scottish Canals is responsible for 137 miles of waterways, including reservoir dams and many miles of earth embankments. The spatial and temporal dynamics of soil moisture content can have a critical effect on slope stability; however, measurement of soil moisture over large areas is not achievable using conventional soil physics techniques. Geoelectrical methods can be used to monitor the physical properties that act as proxies for soil moisture. In particular electrical resistivity tomography (ERT) is a volumetric imaging technique that can, indirectly, detect and image changes in the moisture content of the subsurface, thereby having the potential to provide early warning of hydraulically induced slope failures. But ERT algorithms typically assume that the geometry of the region being studied does not change with time. The advances proposed in this project will allow researchers at the British Geological Survey (BGS) and Lancaster to explore new ways of exploiting geophysical methods for improving the resolution of hydraulic precursors to slope failure in dynamic environments – thereby providing early warning of slope failure events.

The focus of the research will be on (1) developing existing geophysical methods to characterise slope failure process mechanisms; (2) quantification of uncertainty in the prediction of soil hydraulic conditions relevant to slope failure. A challenge is to develop new geophysical inversion algorithms that are adaptive to changing geometry in the region of interest. At-risk earthworks are subject to fluctuating water levels, subsidence and deformation, making conventional fixed geometry methods inappropriate (or unreliable). Building on existing codes developed by Binley we will formulate adaptive inversion strategies specifically focussed on slope failure problems. We will also explore new ways of modelling geophysical data in a 4D (3D space + 1D time) manner, e.g. by incorporating spatial and temporal regularisation which may be influenced by soil water physics processes/models. The ability to resolve changes in moisture content from geophysical images is critical, requiring some insight into petrophysical relationships describing links between measurable geophysical properties (e.g. electrical resistivity), soil moisture and other states/properties. Uncertainty in these relationships will propagate through the imaging process, as will the uncertainty due to the non-linear inversion itself. It is therefore essential that sources of uncertainty and their impact on the inverse model (a 4D representation of soil moisture at the site) are assessed and quantified, particularly given the anticipated uses of the new approaches developed.

Before deployment at the field site, the algorithms will be tested using data from numerical modelling and laboratory simulations to determine their accuracy and the benefits gained over standard inversion codes that assume static geometries. Early in the project a number of sites will be identified within Scottish Canals’ assets to test the developed methodologies and demonstrate their wider applicability in a range of setteings. The test site(s) will be instrumented with permanently installed ERT monitoring electrodes and markers to permit measurement of the surface deformation. Representative material samples will be taken for laboratory testing to develop property relationships to translate geoelectrical properties into moisture content. The results from the field trials will be assessed against standard monitoring techniques to determine the ability of our new adaptive approach to provide early warning of failure.

BGS and Lancaster recently developed a partnership, principally in the area of subsurface fluids and energy. This project will develop this partnership further by an alliance in geophysical imaging, which, we anticipate, will help seed future external research funding proposals. Both BGS-Keyworth and Lancaster have expert knowledge of the geophysical tools to be deployed and appropriate modelling methods. The work clearly has an ‘impact’ focus, which we believe is perfectly aligned with both BGS’s and NERC’s mission to deliver solutions to major environmental challenges.

The student will benefit from a wide international network of collaborators that the supervisory team provide. It is envisaged that the student will have the opportunity to travel overseas to interact with collaborating groups in Europe or the US.

Application procedure: Candidates wishing to apply for a BGS-hosted studentship must complete the postgraduate application form of the university where they will be registered by the deadlines indicated plus send:

  • current CV
  • names and addresses of two referees
  • personal statement written by the candidate; no longer than 1 page of A4, containing project title and detailing their reasons for applying to study a PhD and why they have selected their chosen doctoral research project

By e-mail to bufi@bgs.ac.uk

Geology and Regional Geophysics
Forecasting historic landslide reactivation for future wetter climates

BGS Supervisor: David Boon, Geology and Regional Geophysics

University Supervisor: Dr T C Hailes and Dr Jose Constantine

DTP: GW4-Plus, Cardiff University

One of the major predictions of future U.K. climate models is that the intensity of winter precipitation events will increase. The result would likely be more frequent precipitation events like those of winter 2012 and 2013, significant for the adverse impact that geotechnical hazards (landslides, floods) had on UK transport infrastructure. The most surprising of these was the reactivation of historic and relict landslides in low-relief areas across Monmouth County, Wales, that have resulted in road closures and threatened homes. The BGS Wales team, in association with the BGS Landslide Response Team, visited several landslide sites for forensic purposes and identified a major gap in our understanding of the landslide hazard on the Devonian Mudstones crop in Monmouthshire.

To address this, using the Monmouth County landslides as an exemplar, the proposed PhD would seek to develop predictive models of the effect of future increases in precipitation on regional landslide hazard across the UK.

The PhD would involve two components:

  1. The student would be trained in and apply state of the art remote sensing methods to objectively identify landslide deposits using airborne LiDAR data. The student would apply two methods, a surface roughness method and a wavelet-based method to create a map of landslide hazard across Monmouth County. The student would work closely with BGS landslide team and geologists in Wales to validate this method using their extensive expertise and available natural hazard mapping.
  2. The student would attempt to model future landslide hazards by coupling future climate models (such as UKCIP) to slope stability models. This section would focus on up to 4 hillslopes, 2 that have ‘failed’ in 2012-2014 and 2 that remained ‘unfailed’ in 2013-2014 but which are only marginally slopes (e.g. Levox in Wye Valley). We would seek to instrument the unstable hill slopes (the failed landslides have been instrumented by our PB partner) with movement and moisture sensors (pieziometers and inclinometers) to assess the subsurface hydrology and movement rates in these slides.

The empirical observations and analysis of available data will be used to develop rainfall trigger-threshold values for indicator slopes in Monmouthshire and create a ground model of landslide hazard that explicitly incorporates soil/rock physical properties, mechanical failure mechanisms, hydrogeological conditions, future precipitation forecasts.

The resulting will support high-level assessment of potential future impacts to key infrastructure and compliment the work of the BGS Shallow Geohazards and Risks Team to define landslide domains, and to define rainfall-trigger thresholds within these, and will support development of the Natural Hazard Impact model (NHP).

Application procedure: Candidates wishing to apply for a BGS-hosted studentship must complete the postgraduate application form of the university where they will be registered by the deadlines indicated plus send:

  • current CV
  • names and addresses of two referees
  • personal statement written by the candidate; no longer than 1 page of A4, containing project title and detailing their reasons for applying to study a PhD and why they have selected their chosen doctoral research project

By e-mail to bufi@bgs.ac.uk

BGS CASE opportunities

Climate and Landscape Change
Modelling glacial-interglacial landscape evolution

BGS Supervisor: Andrew Finlayson

University Supervisor: John Wainright and Stewart Jamieson

DTP: IAPETUS, Durham

Landscapes in temperate regions evolve as a function of erosion under a wide range of climates. Landscapes also inherently pre-condition any future patterns of erosion as they focus the flow of water, sediment and ice as a function of the distribution of slopes and of valleys. Depending on whether the climate is in a cool glacial phase, or a warmer interglacial phase, the dominance of particular processes alters. However, the relationships between these different forms of landscape evolution and their importance for pre-conditioning further erosion patterns is not well understood. In the context of ice behaviour this is important because the topography inherently controls the way the climate and Earth’s surface interact to grow glaciers or ice sheets whereby the size, shape and stability/dynamicity of the ice is fundamentally tied to the shape of the underlying landscape. Conversely, from a fluvial and hillslope perspective the morphology of valley floors will affect both type of river form, amounts of incision and hillslope response. Furthermore, because geomorphologists have tended to be focussed on single process domains, the interactions between these processes over a range of timescales has received very little attention.

The aim of this project is to understand how interactions between different modes of landscape evolution may condition processes and rates of erosion over the longer term. For example, over glacial-interglacial timescales the behaviour of glaciers and ice sheets will change as a function of hillslope and fluvial erosion during interglacial periods. Thus, landscape evolution is likely to be highly contingent on the past history of landscape evolution, thereby requiring an approach that takes account of the feedbacks between all the different processes in operation.

This study will answer fundamental questions such as:

  1. How are ice sheets controlled by previous river and hillslope erosion?
  2. To what extent can river and hillslope processes reset glacial landscapes?
  3. What are the critical timescales over which landscapes adjust to past climate conditions?

Methodology: The project will involve coupling a suite of separate, existing numerical models of river, hillslope and glacial landscape evolution. Simulation experiments will be carried out on landscapes ranging from valley-scale to regional scale and involve a case study based upon the evolution of the English Lake District – a strategically important region in terms of landscape evolution, due to the positioning of present-day radioactive waste processing and storage facilities.

Rates of landscape evolution will be constrained by geological sediment thickness / volume models, based on a dataset of established borehole stratigraphy held by the British Geological Survey. This will involve short placements at BGS (approximately 3 months in total) to receive training in geological modelling, and to develop the geological models that will constrain the process modelling. Models outputs will be tested using existing cosmogenic and thermochronometric datasets, with the possibility of using the model output to define critical areas for the collection of new cosmogenic dating data.

Timeline

Year 1: develop an understanding of landscape evolution and its controls; receive training in numerical modelling; develop a modelling framework for ice sheet and hillslope-fluvial erosion models to be coupled; carry out the coupling of the models.

Year 2: Continue model development. Test the performance of the numerical model in idealized landscapes or landscapes with a well-known evolution history, including appropriate fieldwork in the Lake District. Develop constraining geological model, using borehole dataset and established stratigraphy.

Year 3: Conduct modelling experiments; develop writing skills further; draft publications; present outcomes to IAPETUS and at international conference; draft thesis.

Year 4: Submit thesis; finalize publication manuscripts; attend international conferences.

References & further reading

Finlayson, A. 2012. Ice dynamics and sediment movement: last glacial cycle, Clyde basin, Scotland. Journal of Glaciology, 58, 487-500.

Gallagher K, S Jones, J Wainwright (eds) 2008. Landscape Evolution: Temporal and Spatial Scales of Denudation, Climate and Tectonics. Geological Society Special Publication, London.

Jamieson, S.S.R., Sugden, D.E. & Hulton, N.R.J. 2010. The evolution of the subglacial landscape of Antarctica. Earth and Planetary Science Letters 293,1-27.

Jamieson, S.S.R., Hulton, N.R.J. & Hagdorn, M. 2008. Modelling landscape evolution under ice sheets. Geomorphology 97,91-108.

Melanson A, T Bell, L Tarasov 2013. Numerical modelling of subglacial erosion and sediment transport and its application to the North American ice sheets over the Last Glacial cycle, Quaternary Science Reviews 68, 154–174.

Merritt, J., Auton, C.A.A. 2000. An outline of the lithostratigraphy and depositional history of Quaternary deposits in the Sellafield district, west Cumbria. Proceedings of the Yorkshire Geological Society 53, 129-154.

Wainwright, J 2006. Degrees of separation: hillslope-channel coupling and the limits of palaeohydrological reconstruction, Catena 66, 93–106.

Wainwright J, M Mulligan (eds) 2013. Environmental Modelling: Finding Simplicity in Complexity. 2nd Edition. Wiley-Blackwell, Chichester.

Application procedure: Application is usually via the host university. Please check the relevant DTP website.

Earth Hazards & Observatories
Coalfield Rebound: Environmental Threat or Energy Opportunity?

BGS Supervisor: Dr Luke Bateson

University Supervisor: Professor Jon Gluyas, Durham University

DTP: IAPETUS, Durham

Further information: Professor Jon Gluyas

Overview: The deep coal mining history of the UK flourished for around 300 years until its demise in the 1980s. In the last 100 years of the industry some 15 billion m3 of coal had been removed. Collapse of the overburden was inevitable part of the mining process. We estimate some 2 billion m3 of void space remains and the most of this is now saturated with water. Working collieries were formerly dewatered by pumping in order to access coal reserves. At abandonment, pumps were switched off and water levels began to recover to pre-mining levels. The Coal Authority re-instated pumping at several sites to control regional mine water levels and prevent emergence of unwanted discharge to controlled waters. Rebound of water levels in many former mining areas has taken place in tandem with ground level movements associated with regional settlement beneath mined “panels” and uplift caused by increased water levels. Methane released from coal mines when water levels were at their lowest is generally quenched as water levels rise but is being vented in some areas know to have recovered, the reasons for this are poorly understood. The combined processes are both a hazard and an opportunity; hazard because of possible induced seismicity and because the green house and potentially explosive methane is being vented and opportunity because the inflowing water represents a low enthalpy geothermal resource and the released methane could be used to upgrade that resource. An understanding of rates of process will allow the geothermal and gas resource to be evaluated as well as understand the consequent hazards of coalfield rebound.

Methodology: InSAR data will be used to assess uplift rate and locations. An airborne methane survey will allow a wide area to be screened for gas release, this then can be followed up with ground based detection for high graded areas. Many abandoned mines are subject to continuous water level monitoring and when combined with the satellite data will enable calculation of water inflow rates and hence transmissivity. Coupled with temperature analysis it will then be possible to evaluate the geothermal resource and supplementary upgrade potential from the vented methane. This will significantly reduce the risk associated with development of district heating schemes. The unique aspect to this research project will be the cross disciplinary nature of the project which combines data and skills from remote earth observation with geochemical surveys and point source water inflow data to mines.

We intend to use the recently-launched Sentinel-1 data for the InSAR analysis. Sentinel-1 is part of the Copernicus programme of the European Space Agency and data is provided free to users. It will view any site in Europe twice in any 12-day cycle, providing ascending and descending passes which will allow the separation of horizontal and vertical components of the mining deformation to be resolved and provide further insight into the geological process. The project will also explore the use of multiple aperture InSAR (MAI) to try to resolve the full 3D vector of displacement.

Timeline:

Year 1: acquisition of InSAR satellite data, processing and interpretation, high grading of areas for airborne survey.

Year 2: airborne survey followed up with ground survey to evaluate methane venting. Acquisition of water inflow data from mine records.

Year 3: integration of all data sets and writing up of thesis. We anticipate this project to deliver 3 detailed papers on the results of the different techniques followed by one covering the integration of all the data. There is further spin out possibilities in terms of geohazard forecasting.

Training & Skills: The student will participate in the Iapetus doctoral training process in addition to the following bespoke training. InSAR data analysis and manipulation, GIS, low temperature water rock interaction and geochemistry, fluid flow in porous media.

References & Further Reading:

Sowter, A., Bateson, L., Strange, P., Ambrose, K. and Syafiudin, M.F., “DInSAR estimation of land motion using intermittent coherence with application to the South Derbyshire and Leicestershire coalfields,” Remote Sensing Letters, Vol. 4, Issue 3, 2013, DOI: 10.1080/2150704X.2013.823673

Bateson, L., Cigna, F., Boon, D. and Sowter, A., “The application of the SBAS (ISBAS) InSAR method to the South Wales Coalfield,” International Journal of Applied Earth Observation and Geoinformation, 34, pp.249-257, 2014.

Application procedure: Application is usually via the host university. Please check the relevant DTP website or contact.

“Earth-like” models of the geomagnetic field

BGS Supervisor: Ciarán Beggan

University Supervisor: Jon Mound

DTP: SPHERES, Leeds University

A full understanding of how the geomagnetic field is generated in Earth’s liquid core remains one of the great outstanding problems in Earth Science. The principal difficulty is that the core is too remote to be probed directly; knowledge has advanced through exploiting a limited set of observations and computer simulations of the Earth’s core. Computational models have improved significantly in the past decade, largely due to technological improvements in computing. Over the same period our understanding of the present and past structure and dynamics of the Earth’s magnetic field has improved due to the continued accumulation of observations from satellite missions and from archaeo- and palaeo-magnetic investigations.

Despite these advances, numerical models still cannot be run in parameter regimes that match physical properties within Earth’s core. Furthermore, questions remain regarding how strongly the boundary conditions at the top and bottom of the fluid core influence the flow within. Do the thermal anomalies at the core-mantle boundary control flow at the surface of the core? Does a persistent translation of the inner core result in uneven heating at the base of the outer core that preferentially promotes convection in one hemisphere, whilst suppressing it in the other? What is the correct balance of forces and boundary conditions to reproduce an “Earth-like” magnetic field?

What is an “Earth-like” magnetic field? Although we cannot expect numerical models to exactly reproduce the Earth’s field, they may be able to reproduce the general structure and dynamics of the field. With proper statistical measures of what constitutes an Earth-like field, we can determine what classes of models best reproduce that field, and thus which models are the most useful analogues of the Earth. Previously used definitions of Earth-like field properties do not include all known constraints on the structure and dynamics of the Earth’s magnetic field: improvements in observations suggest new constraints related to the location, structure and persistence of patches of anomalous field strength and on the patterns of secular variation.

In this project the student will first work to develop new measures that characterise the Earth’s magnetic field and its secular variation. The student will use these measures in conjunction with existing archaeo-magnetic models, to determine the observed behaviour of the Earth’s field on timescales of centuries to millennia. The student will then apply these measures to an existing suite of numerical geodynamo outputs previously produced at the University of Leeds. Insight from these investigations will direct the production of new model runs in order to more fully explore the required ingredients for a numerical model of the geodynamo to exhibit Earth-like behaviour.

The student will learn both the theory and computational techniques required to model the Earth’s core. Training in programming and running code on massively parallel supercomputers will be given.

The student will visit BGS for training in the construction of field models using modern data and techniques. Although the goal of the project is not to create new field models, a thorough understanding of how such models are produced will assist in the evaluation of statistical measures.

Application procedure: Application is usually via the host university. Please check the relevant DTP website.

Investigation of magnetic field modelling using modern computational techniques

BGS Supervisor: Brian Hamilton and Ciarán Beggan

University Supervisor: Peter Richtarik

DTP: E3, Edinburgh University

Magnetic field modelling using satellite and observatory data is a relatively complicated process in which millions of measurements made at different points in space and time are amalgamated together and used to solve for a smaller number (typically a few thousand) Gauss coefficients. There are trade-offs to be made at each stage of the process – from selection of data in a limited local-time window and severe decimation of the data through to ignoring signals from high degree crustal fields and ionospheric effects. The final solution is computed by a linear inversion using an iterative L2 inversion technique, seeking a minimum L1-norm solution.

With advances in satellite technology raising the volume of measurements and a strong desire in the geomagnetism user community for more detailed and magnetic field models, it is time to examine new techniques in computational mathematics for solving large and dense problems such as this. Solving for geomagnetic field Gauss coefficients is not quite a classic ‘big data’ problem but does have some interesting properties that can exploit high performance computing. While newer computers allow the inverse problem to be solved more quickly in a linear fashion, we wish to examine theoretical and computational methods that have evolved in the past decade to allow parallel solving code to be developed. This will allow us to tackle much larger problems looking for many additional ‘geophysical’ signals in a more efficient and rapid manner.

This project will have two parts:

  1. examine and apply the advances in parallel and distributed inverse problem solving using optimization algorithms developed by Peter Richtarik and his group at the University of Edinburgh and with it raise the number and types of geophysical signals that can be resolved; and
  2. investigate alternative methods for posing the inverse problem in geomagnetism.

The first part of the project will be to analyse the types of inverse or optimisation solutions that can be applied to geomagnetic field modelling using Gauss coefficients (a natural manner in which to represent the magnetic field). In particular, the student will examine how to model the inverse problem as optimization problem, and will propose efficient solution techniques scalable to parallel and distributed HPC environments. Once this has been understood, vastly larger problems (“comprehensive modelling”) can be approached, whereby more data and more geomagnetic signals (from the core to the magnetosphere) can be analysed (e.g. Sabaka et al., 2013).

The second part of the project is to investigate other models and methods for solving these problems. This will be a more theoretical approach to the problem of solving the inversion directly for an L1 norm or a different suitable objective, rather than by the current iterative method. It might be possible that alternative mathematical formulations of the basic problem are more amenable to efficient computation, or lead to better-behaved and/or more interpretable solution. The student would need to get acquainted with the advances in mathematical programming techniques and modelling in the recent decade.

Sabaka, T. J., L. Tøffner-Clausen, and N. Olsen, Use of the Comprehensive Inversion method for Swarm satellite data analysis, Earth Planets Space, Vol. 65 (No. 11), pp. 1201-1222, 2013, doi:10.5047/eps.2013.09.007

Application procedure: Application is usually via the host university. Please check the relevant DTP website.

Modelling reversed-polarity patches in the geomagnetic field

BGS Supervisor: Susan Macmillan and Ciarán Beggan

University Supervisor: Phil Livermore

DTP: SPHERES, Leeds University

The Earth’s internally generated magnetic field is a fundamental yet still poorly explained feature of our planet. The internal geomagnetic field is not constant in time, but changes on a timescale of years to decades, with the internal field currently weakening at around 5% per century. This characteristic has been linked to reversed-flux patches at the core surface, where the magnetic field is locally reversed. These patches lead to localised cancellation of the magnetic field on the Earth’s surface, and produces features such as the South Atlantic Anomaly (SAA), a local low-point in the magnitude of the field. There is some evidence that the SAA has existed for at least a few hundred years, and some studies suggest that it may continue to grow and may even be a precursor for a global field reversal. Note that there are also numerous other patches of reversed flux, including in polar regions, whose origin are poorly understood.

The Earth’s core is not accessible to any direct measurement, and recent breakthroughs in our understanding of the dynamics that generate the time-varying internal field are being made through computer modelling. Current understanding suggests two plausible explanations for the reversed-flux patches (for example, those that cause the SAA): either they have arisen through diffusion of a magnetic anomaly within the liquid iron core or they have resulted from the expulsion of deep internal magnetic field through radial upwelling. These weak patches have implications for technology in a number of ways.

For example, low Earth orbit satellites can be vulnerable to high energy charged particles particularly over localised weak-spots in the shielding effect of the internal field, such as when they fly over the South Atlantic Anomaly or the polar regions. Space weather, caused primarily by enhanced solar activity, can also have damaging effects by generating geomagnetically induced currents in power grids, railway signalling and pipelines, and disrupting communications by distortion of the ionosphere. It is an open question as to whether a weakening field will enhance such hazards.

There are thus two key questions:

  1. what are the dynamics of reversed-flux patches and
  2. how do we predict their future structure and possible impact on space-weather hazard.

The first question will be answered by separating out the largest reversed-flux patch, under the South Atlantic Anomaly, from both recent and historical observational models of the internal field. The characteristics of the SAA - for example, its drifting centre point (both on the core surface and the Earth’s surface) - will be compared to other studies in the literature. The SAA will be compared in both size and longevity to other reversed-flux patches on the core-surface, for example, those in polar regions. The most common method of explaining magnetic field change is by modelling advection of magnetic field features by flow at the outer boundary of the liquid core, though it is possible that simple diffusion may be sufficient to explain short-term change, particularly in view of possible stratified layers at this boundary. The student will test these ideas by constructing (forward) models of the time-varying field (both using the entire magnetic field structure, and then considering only the isolated dynamics of reversed flux patches) which are optimised to best fit the available data. Any residual signals (i.e. any discrepancy) may be explicable by the action of more complex horizontal flows, which will be explored using core-flow inversion techniques.

The second part will include methods for forecasting internal field change and the implications for space weather hazard. To do this we will find the computational dynamical model that best fits the evolution of the internal field over the past 150 years (Li et al., 2011) and use this to forecast models for the next (say) 50 years in terms of reversed-flux patch growth, and in terms of overall field decay. These forecasts will be compared with those made by other methods. We will also quantify how well our dynamical models predict the present-day magnetic field given only (say) the magnetic field configuration in the 1980s.

The student will consider the impact of these predictions on space weather. This study will include not only the impact of a broadening SAA region, but also strengthening high-latitude reversed-flux patches. This part of the studentship will be undertaken during a placement at the BGS in Edinburgh.

Application procedure: Application is usually via the host university. Please check the relevant DTP website.

Novel object-based classification methods for lithological mapping in vegetated terrain

BGS Supervisor: Dr Stephen Grebby

University Supervisor: Dr Kevin Tansey and Dr Nick Tate

DTP: CENTA, University of Leicester

Remote sensing plays an important role in geological mapping programmes because it helps to overcome cost, time and accessibility restrictions associated with traditional field-based surveys. Conventionally, this comprises automated classification of remotely sensed data by matching individual image pixel spectra to the spectral signatures of lithologies1. However, studies have illustrated that ≥ 10% fractional vegetation cover (e.g., lichen, grass, scrub) can obscure or completely mask the spectra of underlying lithological substrates2,3, thus severely limiting the utility of conventional remote sensing approaches to only the most arid parts of the world.

Recent advances by the supervisory team have led to the development of novel algorithms that have the potential to overcome the hindrance of vegetation on lithological mapping by exploiting geobotanical and topographical associations as proxies4,5. These algorithms utilise the spectral characteristics of the vegetation and ‘topographic signatures’ extracted from remotely sensed spectral imagery and digital terrain data, respectively, in conjunction with automated classification algorithms. To date, classification has been restricted to use of traditional per-pixel algorithms which result in the lithological maps with somewhat poor veracity due to considerable artefacts (e.g., isolated and spurious pixels). Such artefacts arise due to spatially variable vegetation abundance and local variations in the erosion and weathering effects within lithological units.

A shift from classifying data on a per-pixel basis to classifying groups of homogeneous, contiguous pixels (i.e., objects) may provide one opportunity to enhance lithological mapping. By considering the characteristics and context of objects with respect to neighbouring groups of pixels, object-based classification is capable of out-performing per-pixel approaches6. Despite demonstrating considerable potential for producing accurate, realistic land use/land cover maps, the application of object-based classification to lithological mapping has yet to be comprehensively investigated. However, preliminary results (Figure 1) suggest that such an approach can provide significant gains over the existing algorithms. The development of new parameters, to better capture geobotanical relationships and ‘topographic signatures’, offers another opportunity to enhance lithological mapping capabilities in vegetated terrain. Use of more complex terrain analysis (e.g., wavelets, fractal dimension) and vegetation indices may enable better characterisation of lithologies in terms of their topographical and geobotanical associations, as well as helping to improve the transferability of the algorithms between study areas.

The primary aim of this cutting-edge, multidisciplinary PhD project is to refine and develop novel object-based classification algorithms for enhanced lithological mapping in vegetated areas using spectral and topographical data. The successful candidate will utilise the latest commercial and open-source object-oriented software in conjunction with existing airborne datasets acquired for a number of diverse geological and geographical settings, such as the UK (extensively vegetated), Cyprus (typical Mediterranean scrub, grasses and lichens), Arizona (20% tree cover) and Greenland (predominantly lichens). Such datasets are available via the NERC Earth Observation Data Centre and the NSF Open Topography portal. The main objectives of the project are to:

  1. Establish the transferability of the existing algorithms to other study areas;
  2. Further refine the existing algorithms to incorporate object-based classification;
  3. Devise generic or case-specific geomorphometric parameters/terrain descriptors and geobotanical characteristics for lithological discrimination;
  4. Develop a generic or suite of novel object-based classification algorithms that incorporate the new parameters/descriptors.

In addition to the CENTA-devised research training programme, dedicated multidisciplinary training will be provided in the following key areas:

  • Lithological mapping field skills;
  • Image processing;
  • Terrain analysis/geomorphometry;
  • Object-oriented software (at Aberystwyth University);
  • ArcGIS and 3-D visualisation (using GeoVisionary);
  • Field spectroscopy;
  • High Performance Computing for processing ‘big data’;
  • LINUX system training.

The training programme also includes a 10-day placement based at another research institute or commercial company. The location of this placement will be chosen to be of maximum benefit in complementing and enhancing the knowledge, skillset, experience and future career prospects of the individual.

Further reading:

1 Rowan, L. C., & Mars, J. C. (2003). Lithologic mapping in the Mountain Pass, California area using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data. Remote Sensing of Environment, 84, 350−366.

2 Ager, C. M., & Milton, N. M. (1987). Spectral reflectance of lichens and their effects on the reflectance of rock substrates. Geophysics, 52, 898−906.

3 Grebby, S., Cunningham, D., Tansey, K., & Naden, J. (2014). The impact of vegetation on lithological mapping using airborne multispectral data: a case study for the North Troodos region, Cyprus. Remote Sensing, 6, 10860−10887.

4 Grebby, S., Naden, J., Cunningham, D., & Tansey, K. (2011). Integrating airborne multispectral imagery and airborne LiDAR data for enhanced lithological mapping in vegetated terrain. Remote Sensing of Environment, 115, 214−226.

5 Grebby, S., Cunningham, D., Naden, J., & Tansey, K. (2010). Lithological mapping of the Troodos ophiolite, Cyprus, using airborne LiDAR topographic data. Remote Sensing of Environment, 114, 713−724.

6 Blaschke, T. (2010). Object based image analysis for remote sensing. ISPRS Journal of Photogrammetry and Remote Sensing, 65, 2−16.

Application procedure: Application is usually via the host university. Please check the relevant DTP website.

Separating magnetic field sources using the Swarm satellite constellation

BGS Supervisor: Susan Macmillan and Ciarán Beggan

University Supervisor: Professor Kathy Whaler

DTP: E3, Edinburgh

Eligibility: Applicants should hold a minimum of a UK Honours Degree at 2:1 level or equivalent in subjects such as Computer Science, Physics, Engineering, Mathematics or Natural Sciences.

Enquiries: For further details contact Professor Kathy Whaler

In November 2013 the European Space Agency successfully launched the Swarm mission: three satellites flying in low earth orbit and measuring the magnetic field to unprecedented accuracy for at least the next 5 years. Prior to this the Ørsted and CHAMP satellites launched in 1999/2000 provided the first decadal-length satellite magnetic surveys with globally high spatial resolution. At the same time ground-based magnetic data were collected continuously at geomagnetic observatories across the world. These complementary sources of data prompted development of more detailed models of the Earth’s magnetic field to be made. These models are essential for understanding the Earth’s deep interior but are also of practical use in global navigation and for magnetic directional referencing in the oil industry. They also provide the basis for coordinate systems in ionospheric and magnetospheric field studies.

However, despite our best modelling efforts, there are still problems separating the various sources of the magnetic field which have signals that overlap in both the spatial and temporal domains (for example Beggan et al, 2009). The main source is in the Earth’s fluid outer core and this changes slowly in time, elucidating deep Earth processes and composition. However, magnetised rocks in the Earth’s crust and the highly dynamic ionosphere-magnetosphere system (modulated by the solar wind) both present challenges to separating out the pure core field signal. Although a substantial amount of preparation work for the Swarm mission has already taken place in ‘end-to-end’ simulator models and recovery of the major field sources (Earth Planets and Space, Vol. 65 (11), 2013), the actual data are more complicated.

The over-arching objective of this project is to utilise the improved spatial and temporal resolution of the external fields that the new satellite programme provides to refine magnetic source field parameterisations and models to the point where the individual sources can be much better defined and hence understood.

Examples include:

  1. investigating secular changes in the auroral electrojets and to investigate to what extent the secular changes in the core field signal are involved in this (Hamilton and Macmillan, 2013; Vennerstrom and Moretto, 2013);
  2. applying Ampère’s integral method to Swarm data to quantify in-situ electrical currents in the regions between the satellites, whose existence can invalidate the widely applied source-free assumption in spherical harmonic analysis (Shore et al, 2013). Shore et al (2013) analysed the strength of the currents as a function of latitude, time of the day, and solar activity, and found evidence for intensification at mid-latitudes between midnight and dawn, a time that was thought to be relatively free of currents, but there were very few overflights of the Ørsted and CHAMP satellites that allowed these calculations to take place and
  3. improved resolution of the crustal magnetic field taking advantage of the data from the two lower satellites flying side by side.

As more Swarm data accumulate and depending on interest of student, it is expected other lines of enquiry will develop.

The project will suit a student with a background in geophysics, physics, mathematics, or computing science. Skills to be developed include methods of data selection, and computational methods, including inverse theory and methods suitable for handling large data sets.

References:

Beggan, C.D., Whaler, K. A., and Macmillan S. (2009), Biased residuals of core flow models from satellite-derived 'virtual observatories', Geophysical Journal International, 177, 463-475. doi:10.1111/j.1365-246X.2009.04111.x

Hamilton, B. and Macmillan, S, 2013. Investigation of decadal scale changes in the auroral oval positions using Magsat and CHAMP data. Poster at IAGA 12th Scientific Assembly, http://nora.nerc.ac.uk/503037/.

Shore, R. M.; K. A. Whaler; S. Macmillan; C. Beggan; N. Olsen; T. Spain and A. Aruliah, 2013. Ionospheric mid-latitude electric current density inferred from multiple magnetic satellites, J. Geophys. Res. Space Phys., 118, 5813–5829, DOI: 10.1002/jgra.50491.

Vol. 65 (11) Swarm Special Issue of Earth, Planets and Space, 2013, http://www.terrapub.co.jp/journals/EPS/frame/65.html.

Application procedure: Application is usually via the host university. Please check the relevant DTP website.

Spherical Slepian function modelling of the magnetic field to probe the outer core

BGS Supervisor: Ciarán Beggan and Susan Macmillan

University Supervisor: Professor Kathy Whaler

DTP: E3, Edinburgh

Models of the global magnetic field are typically expressed as spherical harmonic expansion coefficients. Spherical harmonics offer a physically-based methodology for estimating the magnetic field at any location and altitude above the surface. However, this approach does suffer from a number of limitations, the most significant being that the representation is global. This means that gaps or large errors in the data that make up the models have global consequences.

The mathematics of this approach are well known, having been developed in the 1840’s by Gauss. In recent years, a new approach using spherical Slepian functions has been developed. Spherical Slepian functions are linear combinations of spherical harmonics that produce new basis functions, which vanish approximately outside chosen geographical boundaries but also remain orthogonal within the spatial region of interest. Hence, they are suitable for decomposing spherical-harmonic models into portions that have significant magnetic field energy only in selected areas. Slepian functions are spatio-spectrally concentrated, balancing spatial bias and spectral leakage. We have previously employed them as a basis to decompose a global lithospheric magnetic field model into two distinct regions of the continental domains and its complement the oceans (Beggan et al., 2013). The drawback is that the model is confined to the surface of a sphere and to scalar values only.

However, recent developments by Plattner and Simons (2013) have opened up the possibility of using the technique to create vector field models (similar to our current magnetic models) which are concentrated into particular regions of interest, and which can be upward and downward continued. For example, we can attempt to remove the effects of the polar gap (as there is typically a 3° gap at the poles in satellite data) or we can exclude the auroral regions (+/- 55° magnetic latitude) or we can model the field solely over the Pacific Ocean, where the rate of change is very low. This will allow imaging of smaller features of the field on the core surface. In addition, we wish to extend this work to directly invert vector data to produce regional models, rather than confining a pre-existing spherical harmonic model to a limited area using Slepian functions (as is currently the case).

The project will use satellite magnetic data collected from 1999-2014 and magnetic observatory data to produce new models of the Earth’s magnetic field concentrated into key areas of interest. The project will compare these models against existing techniques and attempt to improve our knowledge of the magnetic field and its rate of change. Once this has been achieved, the project will examine the advective flow of the liquid along the core-mantle boundary using the improved magnetic field models and seek to elucidate their nature. This studentship will also explore the potential for using spherical Slepian functions to study the Earth’s outer core, both its magnetic field and the flow of the liquid iron that explains the field changes.

The project will suit a student with a background in geophysics, physics, mathematics, or computing science. Skills to be developed include methods of data selection, and computational methods such as geophysical inversion and methods suitable for handling large data sets.

References:

C.D. Beggan, J. Saarimáki, K.A. Whaler, F.J. Simons, (2013), Spectral and spatial decomposition of lithospheric magnetic field models using spherical Slepian functions, Geophys. J. Int. http://dx.doi.org/10.1093/gji/ggs122

Plattner, A., F.J. Simons, Spatiospectral concentration of vector fields on a sphere, (2013), Applied and Computational Harmonic Analysis, http://dx.doi.org/10.1016/j.acha.2012.12.001.

Application procedure: Application is usually via the host university. Please check the relevant DTP website.

Energy & Marine Geoscience
Glacial sculpting and post glacial drowning of the Celtic Sea

BGS Supervisor: Dr. Claire Mellett, Energy and Marine Geosciences

University Supervisor: Prof. James Scourse and Dr. Katrien Van Lendeghem, Bangor University, Dr. Daniel Praeg2OGS, Istituto Nazionale di Oceanografia e Geofisica Sperimentale (National Institute of Oceanography and Experimental Geophysics), Italy

DTP: ENVISION, Bangor University

The primary aim of the PhD is to reconstruct different landform assemblages from geophysical and sedimentological data, revealing how landscapes have evolved offshore the UK and Ireland from the Last Glacial Maximum (LGM) to the present day.

Why do we care about palaeo-landscapes?

Studying the sedimentary records of former ice sheets provides insights into ongoing changes in warming polar regions. Most of the British Isles were covered in glacial ice 25000 years ago, and we now know that this included large areas of the present-day marine environment. What we don’t know is the extent to which the ice sculpted landscapes, how quickly ice melted, coastlines changed or how much sediment was injected into the system by the ice.

What will you study?

In the Celtic Sea, an extensive field of seabed ridges has been interpreted to be the world's largest palaeo-tidal sand banks formed during rising sea levels. However, glacigenic sediments found on some ridges have fuelled a lively debate. Could these be glacial landforms recording grounded ice at the shelf edge, far beyond currently accepted limits? Collaboration among the people behind opposing theories during this project will facilitate high-impact research.

What will you do?

As part of a multi-disciplinary team, you will follow an integrated approach to

  1. Reconstruct glacial to marine landform assemblages and sediment sources. The datasets include geophysical data and many sediment cores. You will spend up to 6 months at the British Geological Survey in Edinburgh.
  2. Test models of Irish Sea Ice Stream retreat and post-glacial palaeo-tidal changes.
  3. Design an integrated glacial to post-glacial history of the Celtic Sea, visualised in a 3D time-lapse model.

What will you receive?

Training and support from word-leading experts including those in the BRITICE-CHRONO Consortium project. You will have the opportunity to present at International conferences. From the British Geological Survey, you will also receive an additional £3500 (£1000 per year) to your stipend.

Application procedure: Application is usually via the host university. Please check the relevant DTP website.

Engineering Geology
Revealing hydrological and biogeochemical heterogeneity at the groundwater-surface water interface using geophysics

BGS Supervisor: Dr Jon Chambers and Dr Daren Goody

University Supervisor: Professor Andrew Binley

DTP: ENVISION Lancaster

Eligibility: Applicants should hold a minimum of a UK Honours Degree at 2:1 level or equivalent in subjects such as Environmental Science, Earth Science, Physics, Engineering, Natural Sciences. No prior experience of applied geophysics is necessary but it will be advantageous.

Enquiries: For further details please contact Professor Andrew Binley

It is now widely recognised that hydrological and biogeochemical processes that occur at the interface of groundwater (GW) and surface water (SW) can have a significant impact on catchment water quality and ecosystem health. Significant heterogeneity in the fabric of the subsurface at the GW-SW interface can lead to complex fluid flow pathways, both of which can exert a strong control on biogeochemical cycling. Revealing such heterogeneity remains a challenge because of the limitations of traditional field experimental processes. In this project we explore the use, and provide additional development, of geophysical methods tailored for characterising the GW-SW interface. Our vision is a suite of tools that can ultimately be utilised along an entire reach of a river, i.e. to investigate an entire catchment.

The project will be primarily field-based, focussing on sites where the supervisory team have already conducted preliminary, related, work. The sites to be utilised are: the Lambourn Observatory in Berkshire (Chambers et al., 2014, WRR, doi: 10.1002/2014WR015643) and the River Leith in Cumbria (Binley et al., 2013, WRR, doi:10.1002/wrcr.20214).

We will explore a range of field-based techniques including:

  1. new multi-coil EM conductivity measurement technology;
  2. electrical resistivity tomography and induced polarisation, exploiting in-stream semi-permanent electrode arrays;
  3. electrical imaging of injected tracers to reveal fluid flow pathways.

A laboratory-based study of river bed sediment samples will explore links between geophysical, hydraulic and geochemical properties.

The student will be given training on the use of geophysical methods, processing and modelling of geophysical data, field and laboratory investigative techniques. The student will also be given the opportunity to spend time at the British Geological Survey, and access to BGS geophysical laboratories and field equipment. The student will gain experimental and modelling skills, along with insight into scale-dependent processes, all of which will be valuable for career progression.

Application procedure: Application is usually via the host university. Please check the relevant DTP website.

Environmental Modelling
Investigating drainage beneath the British-Irish Ice Sheet: groundwater flow modelling and meltwater channel networks

BGS Supervisor: Chris Jackson

University Supervisor: Dr Stephen Livingstone

DTP: ACCE, Sheffield University

Further information: Dr Stephen Livingstone

The behaviour of ice sheets is largely governed by basal conditions at the ice-bed interface. In particular, observations made beneath the Greenland and Antarctic ice sheets reveal significant basal meltwater generation, storage and evacuation; lubricating the bed and facilitating rapid ice-flow. Unfortunately, the basal and temporal form of the hydrological system beneath modern ice sheets is poorly conceived. This is compromising the ability to accurately model processes at the ice bed interface.

In particular, glaciologists have tended to think of the ice-sheet bed as an impermeable surface. However, an overlying ice mass has a major impact on groundwater flow patterns, recharge rates and distribution of freshwater. Detailing the complex aquifer-ice-sheet interactions is therefore a crucial component of the basal meltwater system, both as a mechanism for draining meltwater and in landform and sediment genesis.

An alternative approach to investigating the subglacial hydrology of existing ice sheets is to observe palaeo-ice sheet beds. This is advantageous because we have comprehensive information about the bed properties, and can easily access and examine the glacial sediments and landforms. We can therefore provide detailed information on the form and evolution of the hydrological network (e.g. the pattern of meltwater flow) and investigate their impact on meltwater drainage and ice-dynamics over long time-scales. Moreover, understanding palaeo-groundwater flows has profound implications for water resource managers, in reconciling modern groundwater stores; identifying offshore glacial meltwater plumes; and determining sustainable pumping rates from confined aquifers that hosted glacial meltwaters; in considering the long-term disposal of nuclear wastes; and for biologists investigating microbe evolution in groundwaters.

This PhD project will use the bed of the British-Irish Ice Sheet, which has fully retreated revealing a bewildering array of meltwater features (see figure above), in tandem with a numerical model, to reconstruct the form, evolution and drainage of groundwater and basal meltwater. This will be explored through:

  1. High-resolution (1m, LIDAR) mapping of meltwater channels on the bed of the former British-Irish Ice Sheet.
  2. Using a numerical model to reconstruct the pattern of groundwater drainage during the last glacial.

References:

Clark, C.D., Hughes, A.L.C., Greenwood, S.L., Jordan, C.J. and Sejrup, H.P. (2012). Pattern and timing of retreat of the last British-Irish Ice Sheet.

Quaternary Science Reviews, 44, 112-146.

Livingstone, S.J., Clark, C.D. and Woodward, J. (2013). Predicting subglacial lakes and meltwater drainage pathways beneath the Antarctic and Greenland ice sheets. The Cryosphere Discuss 7: 1177-1213.

Livingstone, S.J., Clark, C.D. and Tarasov, L. (2013). North American palaeo-subglacial lakes and their meltwater drainage pathways: predictions and geomorphological clues to their origin. Earth and Planetary Science Letters, 375, 13-33.

Alzraiee A., Baù D. and L.A. Garcia (2013). Multi-Objective Design of Aquifer Monitoring Networks for Optimal Spatial Prediction and Geostatistical Parameter Estimation, Water Resources Research, 46, Issue 6,DOI: 10.1002/wrcr.20300

Application procedure: Application is usually via the host university. Please check the relevant DTP website or contact.

PRELUDE: PREdictive modelling of Lead concentrations Using g-base Datasets for urban Environments

BGS Supervisor: Fiona Fordyce and Murray Lark

University Supervisor: Margaret Graham and Neil Stuart

DTP: E3, Edinburgh University

Lead is a naturally occurring metal which is toxic to all life; however, numerous studies show that lead concentrations in urban environments are typically elevated above background concentrations as a consequence of anthropogenic sources1,2,3. These include historic use of lead-based paints, leaded petrol and current and historical industrial practices. Although several sources of lead have been largely reduced, e.g. lead in petrol, paint and water piping, human exposure to lead in urban soils is still of concern as recent studies have demonstrated links with elevated blood lead levels and neurobiological issues such as learning difficulties and attention deficit disorders2.

Growing concerns about lead have prompted a recent reduction in the UK soil guideline values for lead. In spite of the large amount of work that has been done, knowledge about the distribution of lead in urban soils poorly documented. Understanding the controls on distribution of lead in urban environments is essential to better predict soil-lead exposure. Previous UK studies have demonstrated broad relationships between greater soil-lead concentrations and land uses such as roads, industry and domestic gardens4,5 but levels are highly variable and relationships with some land use types are equivocal. Novel work in the United States based on a landscape parcel approach has demonstrated the importance of urban landscape features such as buildings, distance to roads and housing age as controls on the distribution of lead and these have been used to spatially predict lead concentrations throughout Balitmore6,7. However, the international applicability of these methods has not been tested.

BGS’ Geochemical Baseline Survey of the Environment (G BASE) datasets on UK urban soil lead provide a unique resource to assess landscape-lead relationships. Based on these datasets, this study aims to assess the landscape parcel approach in the UK urban context for the first time, to develop predictive models for soil lead as an aid to land quality, remediation and human exposure assessments. The study will advance understanding by coupling this approach with state of the art lead isotope techniques to better determine lead sources to improve the landscape prediction models. Building on previous investigations into soil-lead sources8 the study will develop a model for the city of Glasgow, which has an industrial history typical of many UK cities. The model will be validated against UK cities with similar and differing industrial histories to assess the robustness of the methodology.

Key research questions:

  • Can the sources of lead in urban environments be ascertained by exploring relationships between soil lead chemistry and landscape features at a land parcel scale?
  • Are spatial models a viable method for accurately predicting lead concentrations in Glasgow soils and other UK cities with varying development histories?
  • Can these models improve understanding of areas that present a greater risk of soil lead exposure?

Methodology: Initial statistical assessments of soil lead – land use relationships based on the G-BASE Glasgow dataset will be used to optimise a sampling strategy. On that basis, sources of lead will be investigated based on stratified sampling of different land parcels in Glasgow, including residential zones of different ages, roads, industrial sites and parks. Lead isotope signatures and total lead concentrations will be determined by ICP-MS and cross validated against the existing G-BASE soil dataset. Statistical relationships between lead sources and landscape packages will be determined and fed into a range of spatially explicit GIS-based predictive models that will estimate lead concentrations throughout Glasgow including Spatial Linear Mixed Models; Classification and Regression Trees and Multivariate Adaptive Regression Splines. The results will be compared with outputs from artificial neural networks, such as self-organising maps. The G-BASE Glasgow soil lead dataset will be used to train and validate the models. The most suitable predictive model will be applied to other industrial cities similar to Glasgow (e.g. Manchester), and non-industrial cities which are different to Glasgow (e.g. York) where G-BASE datasets are available to assess the validity of the model.

Training: A comprehensive training programme will be provided comprising both specialist scientific training and generic transferrable and professional skills. Specific training in soil sampling, statistics and GIS will be provided by BGS in addition to training in spatial predictive modelling provided by Edinburgh University. Training in analytical methodologies will be delivered by Dr Graham’s laboratories.

Requirements: a 1st Class honours degree in environmental science or geosciences is essential. Preference will be given to candidates with relevant practical experience of environmental sample collection, processing and statistical modelling.

Key References:

1. Fordyce, F.M., Brown, S.E., Ander, E.L., Rawlins, B.G., O'Donnell, K.E., Lister, T.R., and Johnson, C.C., 2005. GSUE: urban geochemical mapping in Great Britain. Geochemistry: Exploration, Environment, Analysis, 5(4), pp.325-336.

2. Mielke, H. W., Berry, K. J., Mielke, P.W., Powell, E. T. & Gonzales, C. R. (2005). Multiple metal accumulation as a factor in learning achievement within various New Orleans elementary school communities. Environmental Research, 97, 67-75.

3. Johnson, C. C., Demetriades, A., Locutura, J. & Ottesen, R. T. (Ed.). (2011). Mapping the Chemical Environment of Urban Areas. London: John Wiley & Sons.

4. Fordyce F M, Nice S E, Lister T R, Ó Dochartaigh B É, Cooper R, Allen M, Ingham M, Gowing C, Vickers B P and Scheib A. 2012. Urban Soil Geochemistry of Glasgow. British Geological Survey Open Report, OR/08/002.

5. Lark R M and Scheib C. 2013. Land use and lead content in soils of London. Geoderma 209-210, 65-74.

6. Schwarz, K., Pickett, S.T., Lathrop, R.G., Weathers, K.C., Pouyat, R.V., and Cadenasso, M.L. (2012). The effects of the urban built environment on the spatial distribution of lead in residential soils. Environmental Pollution, 163, pp.32-39.

7. Schwarz, K., Weathers, K.C., Pickett, S.T., Lathrop Jr, R.G., Pouyat, R.V., and Cadenasso, M.L. (2013). A comparison of three empirically based, spatially explicit predictive models of residential soil Pb concentrations in Baltimore, Maryland, USA: understanding the variability within cities. Environmental Geochemistry and Health, 35, pp.495-510.

8. Farmer J G, Broadway A, Cave, M R, Wragg J, Fordyce F M, Graham M C, Ngwenya B T and Bewley R J F. 2011. A lead isotopic study of the human bioaccessibility of lead in urban soils from Glasgow, Scotland. Science of the Total Environment 409 (23) 4958–4965.

Application procedure: Application is usually via the host university. Please check the relevant DTP website.

Rare earth elements are essential for green technologies but are they damaging human and environmental health?

BGS Supervisor: Joanna Wragg

University Supervisor: Stephanie Handley-Sidhu

DTP: CENTA, Birmingham

Rare Earth Elements (REEs) are listed as ‘critical materials’ by the European Union. REEs are essential for modern electronics and for meeting global commitments to using greener technologies, such as renewable energy (i.e. wind and solar power) and energy efficient vehicles.

World production of REEs has nearly doubled in the last decade and consumption is forecast to reach 210,000 tonnes by 2015. Currently more than 95% of global REE supply comes from China which is causing major geopolitical issues (e.g. soaring REE prices and imposed strict export quotas).

The demand for some REE will eventually out strip supply, leading to grave concerns about the security of supply and an urgent requirement to find alternative sources. The UK has no REE mining operation and few REE resources, though recent exploration has shown that the Caledonian alkaline igneous intrusions of north-west Scotland could be economically viable. However, REE mining/processing in the UK should be approached with caution as poor practices in China have led to significant environmental problems and the toxicological effects of REEs and their mechanism of action are still poorly understood.

Research Hypothesis: REEs mining activities will increase REE contaminant transport in soils/sediments and impact environmental and human health.

Objectives of the Project:

  1. Determine the influence of bio-geochemical conditions on REE speciation and transport in the environment.
  2. Investigate the impact of REE mining on environmental and human health.

Methodology: UK REEs sites will be selected using BGS resources; minerals and underlying soils will be collected. Minerals will be processed to simulate mine tailings for laboratory experimentation.

Column experiments (figure 1b) will be used to investigate the transport of REEs and the influence of biogeochemical conditions (determined by redox indicators) on metal mobility will be determined from breakthrough curves (dissolved and colloidal) and sequential extraction techniques (Chemometric Identification of Substrates and Element Distributions – CISED). DNA profiling and/or metabolic activities (Biolog plates) will be used to determine changes in soil microbial community/health from REE contamination.

Ecotoxicological screening of REE leachates will be assessed using miniaturized bioassays (Phytotoxkit, Ostracodtoxkit, Algaltoxkit, Daphtoxkit from MicroBio Tests Inc, Belgium). The BGS human exposure to REE contaminated water (oral ingestion bioaccessibility) will be determined and the impact to human health assessed.

Application procedure: Application is usually via the host university. Please check the relevant DTP website.

Geochronology and Tracers Facility
New insights into the genesis of copper mineralisation using stable isotope fractionation processes in the Cu-Fe-S system

BGS Supervisor: Dr Matthew Horstwood

University Supervisor: Dr Ian Butler

DTP: E3, Edinburgh

Further information: Dr Ian Butler

Copper is one of the most recycled elements on the planet, yet the demand is such (every person in the UK uses around 4.6kg Cu per year) that half of all the copper ever produced has been mined in the last 25 years, all of this from sulphide ores. We need to find more deposits, and your research will provide fundamental data on the behaviour of Cu and S that will inform new exploration models. You will develop and apply Cu and S isotope analysis to experimentally produced sulphides and to a classic suite of ore samples, to better understand the processes that control precipitation and ultimately the genesis of copper ore deposits.

Copper isotopes undergo significant fractionation in nature spanning 27‰ as δ65Cu1. Multi-collector inductively coupled plasma mass spectrometry (MC-ICPMS) has reduced analytical uncertainties on δ65Cu to below 0.1‰ and Cu isotope systematics are providing new insights into metal cycling in the crust and the formation of economically important ore deposits2. Cu-rich sulphide minerals formed at high temperatures associated with igneous and hydrothermal deposits show a relatively restricted range of Cu isotope compositions clustering about δ65Cu=0‰ ±1‰. In contrast, lower temperature Cu-rich sulphides from hydrothermal vents and sediment-hosted deposits are typically depleted in 63Cu with δ65Cu values as low as −3.4‰. Secondary enriched products associated with supergene processes have the greatest spectrum of δ65Cu spanning -16.96‰ to 9.98‰1. Experimental studies demonstrate that it is redox reactions transforming Cu(II) and Cu(I) that produce significant Cu isotope fractionations3,4, with a correlation between fractionation factor and temperature between 2 and 200°C (Figure 1).

Progressively Cu-enriched mineral replacement sequences are well known in hydrothermal and stratified sediment-hosted Cu deposits and reflect reactions of Fe-Cu sulphide minerals with aqueous Cu (I) and (II). The natural, finely intergrown mineral textures are readily reproduced in the laboratory (Figure 2). Conventional bulk isotope analysis techniques homogenise discrete isotopic signatures, leading to a loss of information about evolving fluid compositions and reaction processes contained within the zoned assemblages. In this PhD project we seek to address the analytical requirements for highly spatially resolved Cu isotope analysis in order to use Cu isotope methods to better understand the evolving ore forming environments associated with both primary deposition and secondary enrichment of Cu minerals.

The research student will focus on the development of nanosecond laser ablation multi-collector inductively coupled plasma mass spectrometry (ns-LA-MC-ICP-MS at NIGL) as a tool to explore the evolution of complexly intergrown Cu(Fe) sulfide mineral textures. Analysis of Cu isotopes will be supported by analysis of S isotopes (at SUERC) to define ore forming fluid sources as well as evidence for the presence of microbial processes in low temperature and supergene systems. Analysis of natural materials from mid-ocean ridge vent sites and economic deposits using world.

Key research questions: How are stable Cu isotope fractionations produced during the formation of complex zoned mineral assemblages which reflect the evolution of chemical and thermal environments during primary Cu mineralisation and secondary Cu enrichment? Can we combine Cu and S stable isotopes to track the evolution of fluid composition, temperature and redox state during mineralisation processes?

Key research questions: How are stable Cu isotope fractionations produced during the formation of complex zoned mineral assemblages which reflect the evolution of chemical and thermal environments during primary Cu mineralisation and secondary Cu enrichment? Can we combine Cu and S stable isotopes to track the evolution of fluid composition, temperature and redox state during mineralisation processes?

Training: A comprehensive training programme will be provided comprising both specialist scientific training and generic transferable and professional skills. You will be trained in modern methods of isotopic analysis at two NERC Facilities, gain expertise in metal sulphide mineralogy (at Edinburgh) and economic ore deposits (at the BGS and SUERC), the design and implementation of experimental programmes, and in computational geochemical modelling. NIGL co-ordinates and runs a programme of shortcourse training courses and as a BGS-supported PhD studentship the candidate will have access to a range of BGS training courses. In addition, the candidate will be encouraged to present their research results at national and international conferences, gaining key presentation and training skills.

Application procedure: Application is usually via the host university. Please check the relevant DTP website.

Geology & Regional Geophysics
Quantifying subglacial roughness on hard beds: characterising geomorphological and bedrock domains below modern and former ice sheets

BGS Supervisor: Dr Maarten Krabbendam

University Supervisor: Dr Robert Bingham

DTP: E3, Edinburgh

Required skills and qualifications prior to application: We seek an enthusiastic student with a suitable Undergraduate and/or Masters Degree qualification equipped with quantitative skills in Earth Sciences, Physical Geography and/or Glaciology.

Further information:

Dr. Robert Bingham

Project Summary: Using fieldwork, remote sensing, GIS and DTM analysis, this project will quantify basal roughness at multiple resolutions across distinct geomorphological and lithological terrains below modern and former ice sheets.

Aim and Key Research Questions: High resolution roughness is widely seen as a crucial parameter in controlling ice-sheet flow, and hence ice-sheet response to climate change, but is in essence unknown beneath modern ice sheets. The overarching aim of this project is to constrain the roughness of beds beneath modern ice sheets at a higher resolution than has previously been possible, through analysing newly-available and highly detailed datasets from deglaciated terrains.

Key research questions are:

  1. Are there systematic variations in roughness depending on the underlying bedrock domain (e.g. basement gneisses versus sedimentary rocks) of former ice sheets?
  2. What is the range of roughness between specific geomorphological domains (hard-bed/areal-scoured versus soft-bed/palaeo-ice stream beds) of former ice sheets?
  3. What is the basal roughness of mapped hard-bed paleo-ice streams compared to their slower-moving neighbouring areas?
  4. To what degree can detailed subglacial bed roughness be inferred beneath modern ice sheets using gross bed roughness and inferred geomorphological and bedrock domains?

Background and underlying rationale: Basal sliding and ice flow (hereafter: 'basal sliding') is one of the great unknowns in the dynamic behaviour of modern & former ice-sheets. Modelling of modern ice sheets typically uses an empirical 'drag-factor' which comprises two independent, poorly constrained, components: the behaviour of sliding ice near the base and the character of the bed itself, i.e. its roughness. Given a particular drag value: is sliding difficult, but the bed smooth? Or is sliding easy and the bed rough? Subglacial bed roughness thus forms a crucial constraint on ice flow. Ice velocity is known to be broadly influenced by basal roughness (Bingham & Siegert 2009; Rippin 2013). In present-day ice sheets, however, basal roughness derived from Radio-Echo Sounding (RES) is only known at low resolution (>100m), whereas glacial sliding theories (Weertman 1957, Schoof 2004) suggest small-scale roughness (<10 m) controls the dominant sliding mechanism. Basal roughness is scale dependent (Prescott 2013) so currently available low-resolution RES datasets of modern ice sheets are of limited use to deduct roughness at the resolution where it impinges upon basal sliding mechanisms. This conundrum forms an outstanding gap in our understanding of ice-sheet behaviour.

High-resolution (<10m) DTMs from formerly glaciated terrains can be used to quantify bed roughness where available. The best such currently available dataset is the NEXTMap DTM (Intermap Technologies), covering the entire UK landmass, and high-resolution side-swath bathymetry from offshore UK. Medium-resolution (~90 m) global datasets (NASA-SRTM) can be used in the vast deglaciated parts of Canada. The glacial history as well as the bedrock and Quaternary geology of Britain and Canada are well studied and provide reliable background information to test hypotheses.

It is now known that a number of hard-bed palaeo-ice streams existed in the former Laurentide and British ice sheets (Eyles 2012; Bradwell 2013). An outstanding question is what is the basal roughness of these ice streams is compared to their slower-moving neighbouring areas.

Small-scale roughness is known to vary with bedrock geology: basement gneiss typically has a very rough terrain, whereas other rock types are smoother (Krabbendam & Bradwell 2014). This observation can be used to extrapolate small-scale roughness beneath modern ice sheets, where bedrock geology can be inferred. However, the variations in basal roughness for different bedrock types need to be quantified before such extrapolation is meaningful for ice-sheet modelling.

Methods and Activities: The main databases we will analyse include NextMap DTM (InterMap Technologies), offshore side-swath bathymetry (provided through BGS), NASA-SRTM data (open access), Antarctic and Greenland radar data (from Operation IceBridge).

  1. Undertake initial assessment of different surface-roughness determination methods, and identify the essential parameters which are meaningful at different scales ;
  2. Analyse surface roughness across bedrock boundaries along former glacial flowlines in deglaciated terrains in the UK and Canada;
  3. Quantify characteristic differences in surface roughness signatures between hard-bedded and soft-bedded geomorphological domains;
  4. Undertake geomorphological fieldwork to obtain more detailed knowledge of palaeo-glaciological conditions (erosion vs deposition; abrasion vs plucking) along selected transects in UK and Canada
  5. Downscale (sub-sample)DTMs from deglaciated terrains, thereby to simulate the typical scales at which basal roughness is retrieved from modern ice-sheet RES datasets; and analyse the degree to which methods 2 and 3 above can be applied to the Greenland and Antarctic ice sheets.
  6. Determine the importance of directionality of roughness with respect to ice flow depending on the nature of the underlying surface (gneisses versus sedimentary rocks; hard versus soft beds).
  7. Production of thesis, to be based around the production of publishable peer-reviewed manuscripts for in international journals.

Training: The Project combines glaciological expertise of Edinburgh Glaciology and Cryosphere Group with geological and geomorphological expertise as well as DTM analysis capabilities at BGS.

A comprehensive training programme will be provided comprising both specialist scientific training and generic transferable and professional skills. The student will receive training in valuable and employable glaciological and geological techniques including remote-sensing, 2D and 3D DTM analysis and geomorphological field mapping. S/he will benefit from working with an internationally leading team based in the Edinburgh Earth and Environment (E3) Doctoral Training Partnership, and from collaborative supervision through British Geological Survey. The student will receive support to attend national and international conferences and workshops to disseminate findings to the scientific community, and be encouraged to prepare and submit scientific papers to peer-reviewed literature. The student will also have the opportunity to participate in a multitude of transferrable skills training run by the University of Edinburgh, including participation in the School of GeoSciences Graduate School, which provides training in research skills such as preparing and delivering conference talks.

References:

Bingham, R.G. and Siegert, M.J., 2009. Quaternary Science Reviews, 28, 223-236.

Eyles, N., 2012. Quaternary Science Reviews, 55, 34-49.

Krabbendam, M. and Bradwell, T., 2014. Quaternary Science Reviews, 95, 20-42. Rippin, D.M., 2013. Journal of Glaciology, 59, 724-732.

Prescott, P., 2013. PhD Thesis, Durham University.

Schoof, C., 2005. Proceedings of the Royal Society, A 461, 609-627.

Application procedure: Application is usually via the host university. Please check the relevant DTP website.

Spatial and temporal variation of Quaternary uplift rates from dating of cave deposits

BGS Supervisor: Andrew Farrant

University Supervisor: Dr D A Richards

DTP: GW4-Plus, Bristol University

Quantifying how landscapes respond over time to past and future environmental change is an essential requirement for constructing, validating and constraining increasingly sophisticated landscape evolution models. Estimates of surface and rock uplift are required for calibrating tectonic and isostatic models, for designing nuclear waste repositories, for modelling former ice sheets, to deciphering the fluvial terrace record and to assess the response of landscapes to future climate change. In addition, modelling the evolution and vulnerability of groundwater systems over time is dependent on changes in aquifer boundary conditions, especially in karst aquifers.

To obtain rates of landscape change, landforms need to be placed in a chronological framework. Dating surface landforms over Quaternary timescales is often hampered by weathering, surface erosion and the lack of datable material. This is especially problematic in upland regions where erosion is more intense and pre-Devensian deposits are scarce or absent. This issue becomes more acute further back in time. Fortunately, evidence for former landscapes, environments and glaciations is often preserved underground in caves, by both passage morphology and cave sediments including speleothems (Farrant et al., 1995). Former water-table levels and underground drainage patterns can be deduced from cave morphology, whilst cave deposits yield palaeoclimate data. Moreover, cave deposits, particularly speleothems can be precisely and accurately dated by U-Th and increasingly U-Pb, cosmogenic and palaeomagnetic dating methods (Richards and Andersen, 2013).

This study proposes to investigate Quaternary landscape evolution through the application of multiple dating techniques to cave deposits and linking this with surface landscapes and climate. The principal study area will be the South Wales karst (Ford, 1989). This region contains several internationally important cave systems with over 300 km of mapped cave passage, including 6 cave systems >16 km in length. Each contains a wealth of information on past landscape and climatic change. Recent U-Th and U-Pb dating of speleothems from Ogof Draenen, a 70 km long cave system near Blaenavon (Smith et al, unpublished data, Farrant et al., 2014) demonstrates that cave development spans over 1.2 Ma, thus preserving data far longer than surface glaciated environments (typically <40 ka). Moreover, due to their high natural uranium concentrations, speleothems from this area are eminently suitable for novel U-Pb dating techniques. The presence of quartz sand derived from Devonian sandstones washed into these caves also provides the potential for using cosmogenic burial dating methods.

The research will address several key research topics:

  • How fast do landscapes evolve – what are typical rates of valley incision, scarp retreat and surface uplift, and what is their spatial and temporal variability?
  • What drives landscape evolution; steady-state erosion driven by gradual uplift or rapid, pulsed glacially induced incision?
  • What is the speleogenetic response of conduit systems in karst aquifers to base-level fall; do they respond by vadose incision or by phreatic under-capture?
  • Over what timescales do these speleogenetic responses take place?
  • Is there any evidence for pre-Devensian glaciations in upland regions of the UK? Evidence for Middle Pleistocene glaciations are usually confined to lowland sites, and are rare in upland areas. However, recent work in Ogof Draenen near Blaenavon, South Wales (Farrant et al., 2014) suggests the cave system was utilised as a conduit for glacial melt-water during the Anglian glaciation.

The student will build upon previous studies of both cave and surface geomorphology, and apply dating methods to put these into chronological context by U-Th and U-Pb dating of speleothem, backed up by cosmogenic burial and palaeomagnetic dating of cave sediments where appropriate. In addition, the student will use state of the art 3D geological modelling software and digital cave survey data to develop models of conduit inception and cave evolution over Quaternary timescales. Data from other sites in the UK (Farrant et al., 2014b) and overseas, include the Gunung Mulu National Park in Sarawak (Farrant, 1995), and the Matienzo karst in northern Spain will be used as a comparison.

The student will be based at Bristol, with access to state of the art U-Th and U-Pb dating facilities at Bristol and at BGS (NIGL).

References

Ford, T. D. (Ed.). (1989). Limestones and caves of Wales. Cambridge University Press.

Farrant, AR, Smith, CJM, Noble, S, Simms, MJ and Richards, DA. 2014a Speleogenetic evidence from Ogof Draenen for a pre-Devensian glaciation in the Brecon Beacons, South Wales, UK. Journal of Quaternary Science (in press).

Farrant, AR, Noble, SR, Barron, A J M, Self, C A and Grebby, S R. 2014b. Speleothem U-series constraints on scarp retreat rates and landscape evolution: an example from the Severn Valley and Cotswold Hills gull-caves, UK. Journal of the Geological Society (in press).

Farrant, A. R., Smart, P. L., Whitaker, F. F., & Tarling, D. H. (1995). Long-term Quaternary uplift rates inferred from limestone caves in Sarawak, Malaysia. Geology, 23(4), 357-360.

Richards D. A. and Andersen MB (2013) Time constraints and tie-points in the Quaternary Period, Elements 9, 45-51

Application procedure: Application is usually via the host university. Please check the relevant DTP website.

Groundwater
Emerging contaminant fate at the transient groundwater – surface-water interface

BGS Supervisor: Dan Lapworth and Daren Gooddy

University Supervisor: Dr Mike Rivett

DTP: CENTA, University of Birmingham

Emerging contaminants (EC) are ‘microorganics’ of anthropogenic origin and encompass a large array of compounds including pharmaceuticals and personal care products, pesticide degradates and veterinary products. They pose a growing threat to both surface and groundwater quality and there is an urgent need to better understand their environmental behaviour. This PhD aims to assess EC fate at the transient groundwater–surface-water interface (GSI), the key controlling processes that may naturally attenuate ECs, and the wider significance of findings to protection of the environment. Case support to the University of Birmingham (UoB) lead PhD will be provided by the British Geological Survey (BGS) and the Environment Agency (EA). The approach will be field lead, using the BGS peri-urban floodplain site near Oxford to evaluate EC fate under flood/post-flood conditions and the UoB River Tame site to assess EC fate in the riverbed-hyporheic zone. The research will obtain data to allow the assessment of EC natural attenuation at the GSI and establish the relative significance of flow and biogeochemistry. It will utilise the innovative 1000-compound EC screening methods developed by the EA National Laboratory. Interpretation of the field datasets will be supported by a flexible choice of modelling or focused laboratory studies. The EA and BGS will assist in the translation of research findings to improve prediction of EC fate by practitioners. An exceptional training opportunity is offered via the national expertise and facilities at the BGS and EA and access to UoB’s renowned MSc Hydrogeology and MSc Rivers Management programmes.

Methodology: ECs that are often found in rivers due to wastewater discharges have potential to be attenuated in the floodplain and riverbed-hyporheic zone. The field-lead PhD will utilise the BGS peri-urban floodplain site on the Thames to evaluate EC fate under flood/post-flood conditions and the University’s River Tame site to assess fate in the dynamic riverbed-hyporheic zone. Field data will allow the transient natural attenuation of ECs to be assessed and relative significance of flow and biogeochemical controls to be established. This is challenged by the dynamic flow conditions and probable spatial heterogeneity in processes. The PhD will use and develop novel techniques including integrated-time passive EC sampling, fibre-optic distributed temperature sensor, isotope, and smart-tracer methods. It will utilise the innovative 1000-compound EC screening methods developed by the Environment Agency. Interpretation of the field data will be supported by a flexible choice of modelling (flow/geochemical) or focused laboratory studies (column/batch tests).

Training and skills: The student will receive an exceptional training opportunity in environmental and hydrogeological field, laboratory and modelling techniques pertinent to the project and future professional employment in these fields. Specifically they will:

  1. be able to attend modules on the University’s renowned MSc Hydrogeology and MSc Rivers Management programmes,
  2. receive hands-on training in a wide range of advanced field and laboratory analysis techniques during placement at the BGS in Wallingford who have extensive facilities
  3. obtain specialised training in emerging contaminant analysis through project collaboration with the Environment Agency National Laboratories who are the European leaders in this field.

CENTA students will attend 45 days training throughout their PhD including a 10 day placement. In the first year, students will be trained as a single cohort on environmental science, research methods and core skills. Throughout the PhD, training will progress from core skills sets to master classes specific to the student's projects and themes.

Partners and collaboration (including CASE): This study will be supported by a CASE award from BGS and will include a placement at BGS Wallingford, as well as in-kind assistance and hands on experience at the Environment Agency (EA) state-of-art National Laboratory facility at Starcross, Exeter. Fieldwork will be based at the BGS Oxford observatory (as well as the R. Tame UoB research site), a research site with a range of relevant and active projects focused at understanding flooding processes and hydrochemical functioning within peri-urban floodplains. Translation of research findings to allow more ready prediction of EC fate by practitioners will be faciliated through input by EA and BGS.

Timeline:

Year 1: Project mobilisation including literature study, field site(s) programme design, hands-on training in lab and field methods; Installation of field site infrastructure and development of novel technologies (e.g. EC passive samplers); Initiation of field site monitoring and supporting lab analysis programmes. Characterisation of flow regimes and ECs of concern.

Year 2: Continuation of field site monitoring and supporting lab analysis programmes. The focus will be

Year 3: Completion of field monitoring programmes and progression of data analysis and interpretation through quantiative and modelling analysis. Translation of research to the user community. Thesis and journal papers write up. Identification of follow up projects / knowledge exchange opportunities.

Application procedure: Application is usually via the host university. Please check the relevant DTP website.

Combining remote sensing, novel in-situ temperature sensing techniques and ecosystem models for improved environmental risk assessment related to shallow groundwater

BGS Supervisor: John Bloomfield and David Macdonald

University Supervisor: Professor Anne Verhoef

DTP: SCENARIO, University of Reading

Depth to shallow groundwater is a controlling factor for groundwater-dependent ecosystems, agricultural production and shallow geohazards such as landslides and urban groundwater flooding. In these situations accurate, high-resolution spatio-temporal estimates of groundwater levels (GWLs), at a range of receptor-related scales, would significantly improve management and risk assessment.

Continuous point-scale measurements of GWLs can be obtained from pressure transducers installed in piezometers, but this approach does not allow for GWL mapping at a sufficient spatial resolution, as it is not feasible to put in place the large number of sensors necessary.

Shallow groundwater fluctuations are implicit in the land surface temperature (Ts) signal, because Ts is strongly affected by extraction from shallow groundwater via root water uptake (transpiration) and direct soil evaporation, that are sustained for longer in the presence of shallow groundwater. Shallow groundwater also directly influences soil temperatures, Tsoil, and hence Ts. The potential for the spatial mapping of GWLs using thermal remote sensing has therefore been explored since the advent of remote sensing technologies, with thermal infrared (TIR) sensors mounted onboard satellites and airborne facilities recording land surface temperature.

However, evapotranspiration (i.e., latent heat flux) is not the only component of the land surface energy balance that has Ts as a central variable; Ts controls sensible heat and soil heat fluxes and also net radiation that drives the other fluxes. Hence, the relationship between Ts and GWL is by no means straightforward, and this is the main reason why detection of shallow GWLs using TIR has been all but abandoned, despite its potential. A way out of this impasse is the combination of Ts estimates with mechanistic Soil-Vegetation-Atmosphere Transfer (SVAT) models that link below-ground processes (coupled heat-and water transfer) with the above ground land surface fluxes, taking into account the contributions of soil and vegetation fluxes.

We propose a re-examination of the suitability of TIR, taking advantage of recent technological advances in thermal monitoring, as well as state-of-the-art SVAT models. Technical developments include affordable high-resolution infrared cameras mounted on unmanned airborne vehicles (UAVs) that make it cost-effective to undertake precision repeat remote imaging. Furthermore, we propose the use of novel distributed temperature sensors (DTS) in the form of long cables installed below and at the surface, to help interpret the complex relationship between Tsoil, Ts and GWLs (from existing GWL monitoring networks). In addition, we propose the combination of thermal remote sensing with SAR (synthetic aperture radar) to obtain concurrent estimates of soil moisture content and vegetation density.

We will test whether successful remote determination of GWLs from TIR is feasible once the various confounding contributions to Ts have been accounted for by detailed SVAT modeling. The study will be linked with ongoing work within BGS on assessing risk in relation to: ecosystem status, flood management and landslides. It is envisaged that the study will use BGS/UoR project case study sites with existing infrastructure that is monitoring complementary environmental variables, e.g. in the Oxford Floodplain, Boxford and Hollin Hill Observatories. The application of study site results to address regional-scale issues will be explored.

Application procedure: Application is usually via the host university. Please check the relevant DTP website.

Minerals & Waste
BLUE MINING: What drives hydrothermal systems and how does it vary over time?

BGS Supervisor: Paul Lusty

University Supervisor: Dr Bramley Murton

DTP: SPITFIRE, Southampton University

Further information: Dr Bramley Murton

Increasing global demand for minerals, set against the general trend of declining ore grades and mineral deposit discovery rates, will have a tendency to push the minerals industry into more extreme and technically challenging environments. Whilst there are many land-based options which can contribute to future mineral supply, exploitation of deep-ocean mineral deposits is increasingly likely. Since their discovery in 1979, hydrothermal vents on the deep ocean floor at mid-ocean ridges have been the focus of some of the most dramatic scientific discoveries in marine biology and geology. The massive sulphide mineral deposits they form, that are rich in copper, zinc, gold and a range of other trace metals of increasing economic importance are attracting great interest as potential future sources of metal.

Despite years of research on active systems, many fundamental questions remain unresolved. For example, what is the heat source driving the system and what are the sources of metal and sulphur in these deposit? If this is magmatic, over what time scales are magmatic sources (magma chambers) active and capable of driving hydrothermal circulation? This is important since the thermal power of the larger vent systems (100s-1000 MW) requires a significant proportion of the entire ridge segment magma supply to power them. Clearly this poses problems for how this heat is extracted and focused to a single point. It also has implications for the location, duration and frequency of formation of hydrothermal deposits on mid-ocean ridges world-wide. Increased understanding of the processes controlling the formation of these deposits is vital for more robust assessments of the total amount of sulphide in the easily accessible neovolcanic zones of the global oceans, and assessing what contribution these deposits could make to future mineral supply. This knowledge has important implications for more efficient mineral exploration and targeting the most prospective parts of the extensive (64000 km in length) global ridge system.

Methodology: The objective of this project is to look at the history of hydrothermal venting as recorded in sedimentary sections close to extinct massive sulphide mounds in the ALVIN zones, at 26°N, Mid-Atlantic Ridge. Murton is leading a research cruise to this area in early 2016 (as part of his EC-funded project – ‘Blue Mining’) and one of the objectives is to acquire cores from sediment ponds in the vicinity of the deposits. Studies from elsewhere in the Atlantic have shown that similar cores contain a record of hydrothermal discharge, its chemistry and supergene alteration at the sites. The research here will involve analysing core material to determine ages (using C14 etc.) to establish an age model for the system. Using ICP-MS analyses, the metal-rich horizons will be profiled for changes in their composition (e.g. Cu/Zn ratio) indicative of varying conditions of discharge through time. Changes in oxygen/reduction profiles and pore water chemistry through the sediment cores will be examined to determine how these relate to compositional changes (dissolution/scavenging) in redox sensitive elements. This work will be related back to the Blue Mining project – which includes seismic, magnetic and EM studies around the sulphide mounds, and drilling though them, to elucidate the full history of the mineralizing system.

Further reading

Hannington, M., Jamieson, J., Monecke, T., Petersen, S., & Beaulieu, S. (2011). The abundance of seafloor massive sulfide deposits. Geology, 39(12), 1155–1158. doi:10.1130/G32468.1

Lowell, R. P., Farough, A., Hoover, J., & Cummings, K. (2013). Characteristics of magma-driven hydrothermal systems at oceanic spreading centers. Geochemistry, Geophysics, Geosystems, 14(6), 1756–1770. doi:10.1002/ggge.20109

Scott, S. D. (1983). Chemical behaviour of sphalerite and arsenopyrite in hydrothermal and metamorphic environments *. Mineralogical Magazine, 47(December), 427–435.

Training and skills: The student will receive supervision and training in geochemical analyses including ICP-MS, ICP-OES, XRD, and XRF. They will receive supportive supervision in all aspects of data interpretation, training in scientific presentation and scientific writing. In addition, the student will have the opportunity to undertake seagoing research on a major ocean-going research vessel. The students will join a vibrant research group in NOC as well as be part of a wider European research programme directed at seafloor mineral resources. All doctoral candidates will enrol in the Graduate School of NOCS (GSNOCS), in which there are currently around 200 full- and part-time PhD students, as well as joining the vibrant volcanology/geochemistry group where ideas and talks are discussed in a small informal group. Graduate students have the opportunity to participate in teaching activities, and have access to a full range of generic training opportunities across the University.

Partners and collaboration: In addition to that provided by BGS the student will have access to the Isotope Community Support Facility (part of NERC’s national capability) at SUERC and the knowledge and experience of Blue Mining research team, which contains a strong industry core and research organisations from 5 EU member states. The student will be expected to spend at least 3 months at the BGS Keyworth site where they will receive technical training in optical microscopy, SEM, LA-ICP-MS analysis and radiometric dating techniques.

Application procedure: Application is usually via the host university. Please check the relevant DTP website or contact

The anatomy of a submarine to subaerial hydrothermal system — Milos island, Greece

BGS Supervisor: Dr Jon Naden

University Supervisor: Dr Dan Smith

DTP: CENTA, Leicester University

Further information: Dr Dan Smith

Outline project description: The increasing demand for raw materials will require new sources of minerals and metals, and the exploitation of submarine deposits is increasingly likely. However, the exploration for submerged mineral deposits (including actively forming ones) is technically challenging. This project will increase our understanding of what the seafloor might look like close to a submarine hydrothermal system, answer fundamental questions on marine hydrothermal processes and improve the toolkit for explorers.

Milos island, Greece, is a dormant volcanic system in the Southern Aegean Active Volcanic Arc, with resources of gold and silver associated with speciality metals required for green technologies (Te, Sb), Europe’s largest bentonite mine, geothermal energy, and intact blankets of surface hydrothermal alteration. Mineralisation and associated alteration spans a range of environments, from submarine volcanic massive sulfides, to subaerial hot springs. Thermal discharges (submarine and subaerial) are still active in parts of the island. This range of mineralisation styles and activity allows for novel and innovative research into the chemistry and mineralogy of an evolving, emerging hydrothermal system.

The primary research targets are the fossil hydrothermal systems as these present a diverse range of genetically-related environments to study. The active system has an extensive database and, where appropriate, it will be used to underpin and inform research outputs. In terms of the fossil systems, the investigation will centre on the geochemical impacts of boiling in the sub-seafloor environment – recent results from fluid inclusion research indicate that this is a widespread phenomenon where water depths are less than 1000 m. This is important as boiling is a major control on mineral precipitation, fluid chemical evolution, and the formation of secondary (steam-heated) hydrothermal fluids. In terrestrial systems the influence of boiling on mineralisation is well-understood. However, in shallow marine and emergent systems the presence of seawater acts and an additional influence on a range of parameters from hydrothermal fluid composition to the location of boiling zones, and by comparison with terrestrial systems these are poorly understood. This project will determine the role of boiling and secondary fluid formation on the anatomy of the fossil submarine to subaerial hydrothermal system of Milos and the results will feed into developing a new understanding of shallow submarines hydrothermal systems in general, such as those associated with Mediterranean volcanoes of Panarea, Kolumbo and Nisyros.

Methodology: Fieldwork will comprise detailed mapping and sampling of mineralisation and alteration of key sites on Milos is vital to understanding the spatial organisation of the hydrothermal systems and its products. Fieldwork will build on existing maps and recently acquired high-resolution (1 to 5 m) remote sensing datasets (LiDAR, aerial photography and hyperspectral imagery). Laboratory studies will include petrography of ore and alteration minerals, fluid inclusion microthermometry, mineralogical analysis (SEM and XRD), and geochemical analysis (XRF, EPMA, and ICPMS) of rocks, ore and minerals. A broad dataset is necessary to understand the impacts and effects of the interaction between hydrothermal, marine and meteoric waters. Sulfur isotope data will be used useful to discriminate between seawater and magmatic components. Analyses will be supplemented with modelling of S isotope behaviour in key seafloor processes, including fluid mixing, heating, cooling, boiling and phase separation. Geochemical modelling will be used to establish a theoretical framework for hydrothermal processes in submarine and emergent systems. In particular, modelling of fluids and alteration during boiling, phase separation and condensation will be carried out to predict the range of alteration expected in submarine systems, as full analogues of onshore hydrothermal systems. Each of these aspects is standalone and will allow for publication of results as the PhD proceeds.

Training and skills: CENTA students will attend 45 days training throughout their PhD including a 10 day placement. In the first year, students will be trained as a single cohort on environmental science, research methods and core skills. Throughout the PhD, training will progress from core skills sets to master classes specific to the student's projects and themes.

Additional training in the core methods for the project will be available from the supervisory team and colleagues at Leicester and the BGS. Advanced training in geochemical modelling is available in the form of regular international workshops. The project will be undertaken across three CENTA partners giving the student experience of several research environments and multidisciplinarity. It will also address key aspects of NERCs most wanted skills for environmental scientists namely: field skills, numeracy, modelling and handling large datasets. These will equip the student for a future career in either research or industry.

Partners and collaboration: In addition to that provided by BGS and the University of Leicester, further supervision and research training will be provided by Prof E. Valsami-Jones (U. of Birmingham), Prof A. Boyce (U. of Glasgow–SUERC) and Assoc Prof. S. Kilias (U. of Athens). The student will have access to the Facility for Environmental Nanoscience Analysis and Characterisation at Birmingham, the Isotope Community Support Facility (part of NERC’s national capability) at SUERC and the knowledge and experience of the University of Athens submarine mineralisation research team.

The student will be expected to spend at least 6 months at the BGS Keyworth site where they will receive technical training in remote sensing methodologies, Arc GIS and 3D visualisation and be able to use a variety of analytical facilities. Funds are allocated for an international placement.

Possible timeline:

Year 1: Prepare geochemical models of hydrothermal fluids in a submarine setting; predict fluid and mineral compositions related to submarine boiling (and condensation into seawater) and hydrothermal–marine water mixing. Fieldwork in Milos – sampling mineralisation and alteration from known deposits. Preliminary petrographic and geochemical analysis.

Year 2: Petrographic analysis and fluid inclusion studies, further geochemical analysis. Sulfur isotope modelling and analysis. Additional fieldwork. Preparation of manuscripts.

Year 3: Comparison of model results with empirical datasets and submarine systems described in the literature. Additional modelling, e.g. kinetics and reactive transport. Preparation of thesis and manuscripts.

Application procedure: Application is usually via the host university. Please check the relevant DTP website.

Understanding the origin of Rare Earth Element mineralisation in alkaline igneous provinces: the Cenozoic igneous province of North Madagascar

BGS Supervisor: Kathryn Goodenough

University Supervisor: France Wall

DTP: GW4-Plus, Exeter University

The north of Madagascar and the nearby Comores Islands are host to a Cenozoic alkaline igneous volcanic province which has all levels of its igneous plumbing system exposed, from tuff cones that still preserve their surface morphology to syenitic plutons. This igneous province is variously considered to be formed above a mantle plume (Class et al. 2005) or in an extensional rift setting, potentially related to the southern extension of the East African Rift (Melluso et al. 2007); its origin continues to be debated in the scientific literature. This North Madagascar alkaline igneous province (NMAIP) is now recognised as an important source of Rare Earth Element (REE) mineralisation, with one advanced exploration project (http://www.tre-ag.com/operations/tre-project), and more likely to be developed. The REE are critical metals: they are essential for a range of innovative technologies, but global supply is currently derived almost entirely from China. The supervisors have developed good contacts with mining companies in Madagascar, and will have access to the exploration project areas for fieldwork.

The project has twin objectives of developing a petrogenetic model for the source of the magmas, and understanding the processes that concentrate the REE in certain intrusions within the province. The NMAIP offers an excellent opportunity for study of both surface volcanic rocks and the plutons representing magma chambers beneath them. It should therefore be possible to establish what features of volcanic rocks indicate the presence of prospective REE enrichments in shallow plutonic rocks. This will be an important step in the development of a mineral deposit model for this area, which can be applied to other alkaline igneous provinces globally.

Madagascar is not an easy environment for travel and fieldwork, and thus the Cenozoic igneous province has only seen small amounts of study. However, the BGS has carried out a significant amount of work in North Madagascar and the BGS supervisor understands the logistics of fieldwork in the area. We also have good contacts within the mineral exploration industry and with overseas academics working in Madagascar. The student will gain valuable fieldwork experience, which will be beneficial both in terms of the geology and in working in developing countries; this would stand them in excellent stead for a career in mineral deposits research or in the industry. Fieldwork will be carried out with at least one of the supervisors who will provide training in mapping and sample collection. The student will be trained in a range of analytical techniques (petrological, geochemical, isotopic and potentially geochronological) using facilities and supervision at Cardiff and at CSM and will develop a valuable understanding of the formation and evolution of REE deposits. The geochemical techniques to be used include whole rock analysis by XRF, ICP-OES and ICP-MS, and mineralogical analysis by quantitative SEM. An application to the NIGFSC will be put together for the analysis of tracer isotopes (including Nd, Sr, Pb, Hf). Additional XRD, electron beam and quantitative mineral analysis (QEMSCAN) are available at CSM.

Class, C., Goldstein, S L., Stute, M., Kurz, M D., Schlosser, P. 2005. Grand Comore Island: A well-constrained low 3He/4He mantle plume. Earth and Planetary Science Letters 233, 391-409

Melluso, L., Morra, V., Riziky, H., Veloson, J., Lustrino, M., DelGatto, L., Modeste, V. 2007. Petrogenesis of a basanite-tephrite-phonolite volcanic suite in the Bobaomy (Cap d’Ambre) peninsula, northern Madagascar. Journal of African Earth Sciences 49, 29-42

Application procedure: Application is usually via the host university. Please check the relevant DTP website.

BGS Joint opportunities

Climate and Landscape Change
Deglaciation of the Irish Sea basin

BGS Supervisor: Claire Mellett, Energy and Marine Geoscience and Tom Bradwell, Climate and landscape change

University Supervisor: Richard Chiverrell

DTP: TGNES, University of Liverpool

Introduction: The last British – Irish Ice Sheet declined rapidly after 24,000 years ago, with the Irish Sea home to one of the largest ice streams draining this former ice mass. Geochronological modelling constrains the decline of this ice mass to 24,000 to 19,000 years ago (Chiverrell et al., 2013; Mccarroll et al., 2010). The sea floor geomorphology (e.g. van Landeghem et al., 2009) shows the evidence for subglacial landforms and a sedimentary record for this deglaciation. Britice-Chrono is a 5 year NERC Consortium Project running 2012-2018 for which the explicit aim is constrain the rates and styles of ice stream retreat during the last deglaciation. The motivation is that better data are needed by the ice sheet modelling community to test and validate their simulations to increase confidence in future scenarios for Antarctica and Greenland. The recent Britice-Chrono cruise of the RRS James Cook obtained >40 cores and 100’s km of geophysical (seismic) and multibeam morphological data for the Irish Sea. This coupled with >270 cores and a comprehensive survey dataset for the High Voltage Direct Link (HVDL) that crosses the Irish Sea from the Wirral to the Firth of Clyde provides an unrivalled opportunity to test hypotheses about rates and styles of deglaciation.

Project Summary: This project will use an unrivalled geophysical data archive and comprehensive collection of core materials to explore the environments and ice marginal retreat sequence in the Irish Sea broadly north from the Llyn Peninsula to SW Scotland and Cumbria. Focusing almost entirely on the offshore record the project will test hypotheses about: nature and influence of grounded ice, the extent and ice flow indications in the subglacial landforms, the sediment signature across the subglacial to proglacial transition, the extent and degree of marine influence (the glacimarine debate), sediment provenance and ice source / flow paths. The overarching aim is to reconstruct the environmental changes in the basin across this deglaciation. The research will benefit from a comprehensive marine and land-based geochronology developed in parallel through the proposed PhD research (Britice-Chrono) and the PhD candidate would benefit from the connections and research environment of the Britice-Chrono research community (Field and Annual Meetings, and Conferences). The lead supervisor (Chiverrell) is the Terrestrial Lead for Britice-Chrono and Transect Lead for Irish Sea East.

Training: The student will receive training in the use of an array of sediment description and analysis, geophysical data and accompanying software. It will be expected that the student will participate in workshops that provide additional training in research skills, GIS and experimental design. The School of Environmental Sciences requires that the student participate in a comprehensive postgraduate research programme. The British Geological Survey (BGS) is a CASE partner and so though based at Liverpool the student will spend between 3 and 12 months at the BGS during the 3-4 years of your research training. Tom Bradwell and Claire Mellett will be a key part of the supervisory team and contribute to the training programme that will include technical training (e.g. Kingdom and Fledermaus software).

Application procedure: Application is usually via the host university. Please check the relevant DTP website.

Earth Hazards & Observatories
Investigating landslide hazards using multi-wavelength satellite radar images

BGS Supervisor: Dr Francesca Cigna

University Supervisor: Professor Zhenhong Li and Professor Quihua Liang, School of Civil Engineering and Geosciences

DTP: IAPETUS, Newcastle University

Further Information:

Professor Zhenhong Li, Zhenhong.Li@newcastle.ac.uk, 0191 208 5704

Dr Francesca Cigna, fcigna@bgs.ac.uk, 0115 936 3551

Professor Qiuhua Liang, Qiuhua.Liang@ncl.ac.uk, 0191 208 6413

Controlled by geology, climate and land-use, landslides are the most widespread geohazard on Earth and cause billions of dollars worth of damage and thousands of deaths each year. During the first 7 months of 2014, 222 fatal landslides were recorded with a total of 1466 deaths [Petley, 2014], a statistic that has once again demonstrated the importance of understanding landslide hazards and developing early-warning systems.

When occurring near to large water bodies, e.g. reservoirs and lakes, landslides falling into water may generate large waves, and subsequently lead to flooding over the banks or overtopping the dam crest. The flood event caused by landslide induced wave overtopping of Vajont Dam in northeast Italy caused over 2000 deaths in the towns downstream in 1963. Therefore, there is an apparent need to better understand the coupling effects of landslides and the large surface waves they generate and quantify the subsequent impact on the safety of large man-made dams.

The ultimate goal of this studentship is to determine the mechanisms controlling landslide motion. Specific objectives of this proposed research include:

  • to combine multi-wavelength (X-, C-, S- and L-band) satellite radar data to detect active landslides and monitor their dynamics with unprecedented details;
  • to characterise landslide mechanisms and explore the associated triggering factors (e.g. rainfall, water level and seismicity);
  • to determine the dominant geotechnical parameters controlling slope instability, and assess landslide hazards in the near future;
  • to quantify the impact of landslide induced waves on large dams and assess dam safety.

The study will focus on the Three Gorges, in the middle reach of the Yangtze River in China, where landslides represent a major hazard due to the extremely steep slopes on the gorges and erosion of riverbanks. Furthermore, the Three Gorges Dam Project has recently increased landslide hazards in the region following the impoundment from the Dam and consequent water level rise to 175 metres above sea level in 2010.

A wealth of satellite radar data, including X-band TerraSAR-X, C-band Envisat, and L-band ALOS has been collected in this site by the German, European and Japanese Space Agencies, thus creating a rich data reservoir of historical information on this dynamic region. Two data grants have been awarded to the supervisory team to acquire new Kompsat (S-band) and ALOS-2 (L-band) images over the region. Special arrangements are also in place to access ground observations and other geodetic monitoring and topographic data (e.g. GNSS and Laser Scanning) to integrate satellite information and for validation purposes.

Methodology: The PhD student will first exploit conventional Interferometric SAR (InSAR) to detect active landslides at the regional scale. Analysis of the performances of L-, S-, C- and X-band data with respect to surface motion velocity, local topography and land cover (e.g. presence of dense vegetation) will be undertaken, building upon the methodological approach developed at BGS [Cigna et al., 2014]. InSAR time series (e.g. Persistent Scatterer and Small Baseline InSAR) will be utilised at the local scale to monitor extremely slow landslides affecting the steep slopes of the gorges, whilst the SAR Pixel Offset Time-series (SPOT) technique will be employed to monitor the development of fast-moving landslides [Singleton et al. 2014]. GNSS and Terrestrial Laser Scanning will further illustrate details of the spatial and temporal distributions of landslide motion. In situ measurements of rainfall, river water level, and water pressure in the sub-surface will allow the PhD student to directly relate these parameters to the resulting landslide deformation. Results from the detailed geodetic imaging of landslide deformation will improve the understanding of how landslides mobilize in response to changing environmental and hydrological conditions.

To investigate the destructive impacts of landslides that occur in the reservoir, an hydrodynamic model developed at Newcastle University [Smith and Liang, 2013; Amouzgar et al. 2014] will be used to simulate the propagation of the surface waves generated by a landslide and their interaction with the Three Gorges Dam followed by an assessment of dam safety.

Timeline:

Year 1: Training in space geodesy and remote sensing techniques, in particular the handling of satellite radar data, with the aim of detecting and monitoring active landslides in the study sites. In parallel, training will be provided on the mechanics of landslides.

Year 2: The time series of surface displacement maps will be built using the available multi-wavelength satellite radar data, and the impacts of environmental/geotechnical parameters on landslide motion will be assessed. Field work in the Three Gorges region will be carried out to collect field evidence and validate satellite observations. It is envisioned that the combined work of Years 1 and 2 should lead to at least one published output.

Year 3: Modelling surface displacement time series to understand the mechanisms of landslides and simulating landslide induced wave propagation and interaction with the Three Gorges Dam. This should lead to the second and third publications, and presentation at international conferences (e.g. AGU Fall Meeting in San Francisco, USA).

Year 4: The final year of the studentship will be focussed on combining the published outputs and associated material into the PhD thesis. The summary of landslide hazards in the Three Gorges region may lead to the fourth publication.

References:

Cigna F, Bateson L, Jordan C, Dashwood C. 2014. Simulating SAR geometric distortions and predicting Persistent Scatterer densities for ERS-1/2 and ENVISAT C-band SAR and InSAR applications: Nationwide feasibility assessment to monitor the landmass of Great Britain with SAR imagery. Remote Sensing of Environment, 152, 441-466.

Petley, 2014. The landslide blog, http://blogs.agu.org/landslideblog Singleton A, Li Z, Hoey T, Muller J-P. Evaluating sub-pixel offset techniques as an alternative to D-InSAR for monitoring episodic landslide movements in vegetated terrain. Remote Sensing of Environment 2014, 147, 133-144.

Smith LS, Liang Q. Towards a generalised GPU/CPU shallow-flow modelling tool. Computers & Fluids 2013, 88, 334-343.

Amouzgar R, Liang Q, Smith L. A GPU-accelerated shallow flow model for tsunami simulations. Proceedings of the Institution of Civil Engineers - Engineering and Computational Mechanics 2014, 167(3), 117-125.

Application procedure: Application is usually via the host university. Please check the relevant DTP website.

Centre for Doctoral Training: Oil and Gas

Environmental Modelling
The impact of scalar geological heterogeneities on rock property measurements of a wave-dominated deltaic reservoir

BGS Supervisor: Andrew Kingdon, Environmental Modelling

University Supervisor: Peter Fitch, Imperial College

Reservoir sedimentology and rock properties are typically characterised using core and well log data, at specific sampling intervals and measurement resolutions defined prior to drilling. However, the nature and scale of geological heterogeneity will have a significant impact on how it is observed and interpreted from subsequent analysis. The aim of this project is to develop an understanding of how geologic heterogeneities within a wave-dominated deltaic succession can be recorded and characterised in borehole data, and to investigate how the inter-well volume can be predicted using an improved understanding of relationships between vertical and lateral heterogeneities.

Objectives of the PhD research are to:

  1. obtain high resolution observations and interpretations of an outcrop analogue for the Hutton oil field (e.g. North Yorkshire Coast and the Book Cliffs, Utah),
  2. generate synthetic borehole data from the outcrop measurements to explore how key heterogeneities are captured by different measurement tools, across a range of measurement scales,
  3. complete a detailed petrophysical analysis of borehole data acquired at a number of incremental periods through reservoir life of the Hutton oil field (from exploration to decommission*),
  4. integrate borehole imaging data for Brent sequences to understand downhole heterogeneity and
  5. the integration of findings from the outcrop study with those from the subsurface data to enhance our understanding of geological and fluid heterogeneities in mature wave-dominated deltaic reservoirs with the specific aim of improving delineation of geological heterogeneity in flow modelling for these sediments.

Deliverables include:

  1. detailed outcrop analogue observations,
  2. new techniques for relating scalar geological heterogeneity to rock property measurements,
  3. improved understanding of how the numerical character of vertical heterogeneities can be used to predict lateral changes away from the borehole and
  4. insight into flow pathway for improved modelling studies. The multi-scale nature of this study throughout reservoir life will provide novel insights for the identification and production of remaining oil and gas reserves within similar mature hydrocarbon fields of the North Sea.

*The complete geological archive from the Hutton oil field has been made available through the British Geological Survey STARR project.

Application procedure: Application is usually via the host university. Please check the relevant DTP website.