Glacial sediments under the microscope

Above and below a glacier composite.

Glaciologists and Earth scientists are increasingly using a technique known as micromorphology to study the sediments (gravel, sand and mud) left behind as after a glacier or ice sheet has melted away.

This approach can help us understand what is happening deep beneath the icy wastes of modern polar ice sheets like Antarctica and Greenland.

The detailed textures and structures preserved in glacial sediments when viewed under the microscope can be used to:

  • help us understand the processes occurring beneath ice sheets which help them move over the landscape
  • distinguish between sediment laid down in front or beneath glaciers, helping reconstruct ancient glacier margins
  • help understand what happens as the sediments, or even bedrock, deform as the ice bulldozes into, and overrides them
  • investigate the effects of highly pressurised meltwater as it flowed beneath the ice

Collaboration between scientists at the BGS and the Centre for Micromorphology at Queen Mary University of London has led to the development of a new approach to this type of analysis.

This ‘microstructural mapping’ method has the potential to greatly increase our understanding of the complex processes occurring at the margins and below both glaciers and ice sheets.

The study looked at both modern glacial sediments from the Turtmann Glacier in Switzerland, as well as ancient deposits from north Wales and north-east Scotland, and was published in the scientific journal Quaternary Science Reviews in July 2011.

Contact

Contact Emrys Phillips for further information