Surface Deformation & Slope Instabilities in Deglaciating Mountain Environments

This exciting project aims to improve our understanding of the impact of glacial retreat on slope stability and surface and sub-surface deformation in high mountain areas. The project will use the latest satellite data and technologies to measure present-day and past deformation around glacial valleys that have been recently exposed due to retreat. The study has the potential to focus on areas in the High Himalayas, the Pamirs, the Southern Alps of New Zealand, Alaska, Andes and/or Patagonia depending on the candidate’s interests and the progression of the project, and there will be opportunities for fieldwork in some of these destinations if desired.

This project will explore a range of space-based synthetic aperture radar (SAR, e.g. Sentinel-1) and optical (e.g. Planet) imagery (Elliott et al, 2016) to develop quantitative methodologies for assessing surface deformation around retreating glaciers in high mountain areas (Luckman et al., 2007). Characterising this activity is important for assessing the location and rates of loss of ice mass in these areas, as well as for determining changes in the stability of surrounding slopes that may lead to mass failure and, where lakes exist, flooding (Quincey et al., 2005). Attention will be focussed on both glacierised and recently deglacierised terrain, as well as around the glacier margins where periglacial processes are active. On-glacier, measurements of surface deformation from Interferometric Synthetic Aperture Radar (InSAR) may indicate seasonal variations in flow, and/or rates of surface lowering. Surface velocity fields derived for surging glaciers may yield insights into their trigger mechanisms, the processes controlling surge evolution, and/or provide early indication of a developing event. Off-glacier, time-series analysis of slope stability (Dini et al., 2019) may identify the onset or acceleration of failures at the margins and test ideas around the loss of buttressing versus the uphill migration of permafrost as dominant drivers of mass movement events.

Further ideas could explore the potential to examine the stability of moraines at lake margins formed at the toes of retreating glaciers, as these constraints are important for determining the potential susceptibility to failure from shaking events such as earthquakes. It may also be possible to derive horizontal and/or vertical displacements over rock glaciers to provide some novel insight into their poorly-understood dynamics.

Initially the project will focus on the region of the high Himalayas of Central Asia, building on previous studies from within the project supervisory groups (e.g. Quincey et al., 2009 and King et al., 2017) using both SAR and optical imagery as well as digital elevation models (DEMs). Further deglaciating and deformation prone areas will also be targeted such as in the Southern Alps of New Zealand, the Patagonian region of southern Chile/Argentina, the Andes, Alaska or the Pamirs of Central Asia. All of these high mountain areas are becoming increasingly dynamic as the environment warms and the project will seek to quantify the changes that are evident over annual to decadal timescales.