Geophysical measurements are really useful in glaciology. Earlier this month my students and I were working with Christoph Mayer (Bavarian Commission for Geodesy and Glaciology) and Mike McCarthy (British Antarctic Survey), who are expert in applying ground penetrating radar to glaciological research.
With his PhD supervisor, Hamish Pritchard, Mike has recently carried out radar surveys to determine how thick the layer of surface rock debris is on a number of debris-covered glaciers in the Himalaya, which you can read about on the BAS blog here. In our work we were trying to see if we can use high frequency radar to measure even the thin debris cover on Suldenferner. This is pushing the technique to its limits because the layer of rock on Suldenferner is mostly less than 0.2 m thick. Nevertheless we had a go using multiple frequency antennae (400, 600, 900 and 1600MHz), and, despite some initial setbacks associated with conferring our borrowed equipment, the results look promising. Thanks to Christoph, Achim Heilig of the University of Heidelberg and the Innsbruck-based research institute and consultancy AlpS for lending us these various frequency antennae.
Below is a photo of Mike, Christoph and MSc student Costanza measuring a sample profile on Suldenferner, in a brief fair weather interval. The blue dry bag marks the end of the profile.
Hamish and Mike are also both involved in the Bedmap Himalayas project, which aims to use ground penetrating radar to answer a different question, namely, how thick are the glaciers? This is an important question as without knowing the thickness of a glacier we actually cannot say how much ice mass is contained within it. While it is relatively easy to observe the area of a glacier from satellite or airborne images, or from ground mapping, determining how thick the glacier ice is requires this kind of subsurface geophysical investigation.
