Research
Dynamic stability of Greenland Ice Sheet
Following over a decade of research on Alpine hydrology and dynamics, I have explored the extent to which the dynamics of the Greenland Ice Sheet are affected by seasonal injection of surface-derived melt water to the bed and sensitivity of this process to climate change. Through my collaborations with researchers from the Universities of Edinburgh and Bristol, we have published an internationally leading body of highly cited work that has made major progress towards resolving debates surrounding the significance of melt-induced dynamic thinning to the long-term stability of the Greenland Ice Sheet. Related to this, I am currently developing methods for understanding the impact of changing patterns of basal drag on ice sheet dynamics based on satellite-derived measurements of ice sheet surface flow and form.
Surface mass balance of Arctic ice caps and the Greenland Ice Sheet
Fieldwork in early spring of 2000 and 2001 on the Devon Ice Cap and Prince of Wales Icefield, Ellesmere island, involved collection of shallow ice cores, velocity measurements (using differential GPS) and bed topography (using ground penetrating radar). I demonstrated that in situ 137Cs gamma spectrometry could locate the 1963 bomb layer in boreholes throughout the accumulation area of Canadian High Arctic ice caps, allowing mapping of long-term accumulation patterns and provided multi-decadal baseline measurements of ice cap mass balance. This work was further supported by grants from the Polar Continental Shelf Project (Natural Resources Canada) and The Canadian Circumpolar Institute.
I undertook field based research in the interior of the Greenland Ice sheet in 2004 and 2006 to understand the effects of surface melt, refreezing and run-off on the elevation change of ice sheets and to help validate satellite based measurements of ice sheet elevation change.
I am actively developing improved snow and firn evolution models to better understand the sensitivity of melt and refreezing to climate change and to assess the impacts of refreezing processes on the future surface mass balance of Arctic ice caps and the Greenland Ice Sheet.
Greenlandic tidewater glaciers – long-term links between climate and iceberg calving
In the last few years I have increasingly focussed on the issue of iceberg calving, one of the most important, yet poorly understood drivers of mass loss from marine terminating ice sheets and glaciers. The CALVE Leverhulme Trust Research Project Grant unites glaciologists, palaeoecologists and marine palaeobiologists to determine long-term (centennial to millennial) changes in tidewater glacier calving rates with the aim of developing robust models for the relationship between iceberg calving and climate. One novel and imaginative strand of this project is our investigation of the timing of abandonment of sites of Norse occupation in Greenland’s Western Settlement which may provide insight into the resilience of Norse settlement in the face of major environmental change.
Research groups
Research grants
Ice-layer Permeability Controls Runoff from Ice Sheets (IPCRIS)
NATURAL ENVIRONMENT RESEARCH COUNCIL
January 2023 - March 2026