Glacial landforms provide important long-term records of past glacier activity needed to investigate current change; Benjamin Chandler aims to develop a multi-method geophysical approach to maximise the potential of these records
The majority of glaciers and ice-caps are currently undergoing rapid retreat and mass loss in response to rising global temperatures. To contextualise these observations and to better understand and predict the response of glaciers to climate change, we require data on their behaviour at a range of timescales. In this regard, glacial landforms provide numerous and spatially-extensive records of past glacier activity, allowing us to examine their response to climate change in the past.
Undoubtedly, some of the most important landforms for examining past glacier activity are moraines. These are ridges and mounds formed at and along glacier margins. As margin delineators, moraines represent valuable geological archives that contain glaciological information over long timescales (centennial to millennial-scale). These landforms can considerably extend short-term (often decadal-scale) observations of change from direct measurements and aerial/satellite imagery.
To maximise the full potential of moraines, it is necessary to examine their internal composition and structure. However, it is not often possible to do this using standard geological methods, due to the absence of sedimentary exposures and/or restrictions on ‘destructive’ glacial-geological investigations. Near-surface geophysics could address this problem and offer the means to undertake non-destructive subsurface imaging of moraine sequences (as well as other landforms and sedimentary sequences).
As part of my Leverhulme-funded postdoctoral research at Stockholm University, I will apply multiple near-surface geophysical methods to moraines and develop a state-of-the-art geophysical surveying approach. The results of the geophysical surveying will be tested against ‘baseline’ data obtained through standard glacial-geological investigations of the internal composition and structure of the moraines. The ‘testing ground’ for this approach will be the Sarek mountain region, Swedish Lapland. Numerous large, complex moraines exist in this region and they represent an ideal test case for other, less-complex depositional settings to which the same combination of methods could be applied. The aim is to provide a ‘template’ that can be used to exploit the glacial landform record and extract important data on past activity.