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Huw Horgan

2016: Dr Huw Horgan, Victoria University of Wellington, Antarctic Research Centre, has been awarded a Rutherford Discovery Fellowship for research entitled: 'Accelerating Ice – The Role of Water in the Flow of Ice Sheets'.

Biography

Dr Horgan is a geophysical glaciologist who combines remote sensing and applied geophysical methods to study how glaciers and ice sheets flow. After completing an undergraduate degree and MSc at Victoria University of Wellington, Huw was awarded a Fulbright Graduate Award and completed his PhD at Penn State University in their renown Ice and Climate Exploration group. Since beginning work in the Antarctic, Huw has undertaken 14 ice sheet expeditions over 12 field seasons. Underpinning Huw’s research is the use of over-snow geophysical methods. These methods image within and beneath glaciers and ice sheets, and can be used to reveal the controls on fast ice-flow. Returning to New Zealand in 2010, Huw became a Research Fellow in Victoria University’s Antarctic Research Centre and now has a shared position as a Senior Lecturer with the Antarctic Research Centre and the School of Geography, Environment and Earth Sciences. 

Research summary

Glaciers and ice sheets will be the largest contributor to sea level rise over the coming century. Yet, there are still many unanswered questions with regard to how much, and how fast, change will occur. Central to this issue is how ice sheets flow into the ocean. Changes in ice sheet flow are a key uncertainty in future sea level projections, and recent estimates have shown that the Intergovernmental Panel on Climate Change projections may be underestimating the contribution that Antarctica is likely to make.

In the case of the West Antarctic Ice Sheet, ice flow is dominated by ice streams hundreds of kilometers long and tens of kilometers wide, which feed ice into floating ice shelves. The flow of these ice streams is known to change rapidly, resulting in significant changes to rates of sea level rise. One of the primary controls on the flow of ice streams is how they slide over, and deform, their underlying geology. Central to these processes is the presence of liquid water beneath the ice, which exists due to the insulating effect of the overlying ice, frictional heating during ice deformation, and geothermal heat flow. This liquid water can lubricate the base of the ice, smoothing over rough patches and making sediment more easily deformable. Ice streams and glaciers have been observed to accelerate and deccelerate in response to the redistribution of water beneath the ice.

In this research program, Dr Horgan will address the quantity, distribution, and role of water beneath glaciers and ice sheets using a combination of remote sensing, and oversnow geophysical surveying. In the initial stages of the project the distribution of water beneath Antarctica will be mapped from space using elevation and imagery. More detailed knowledge will be provided by oversnow geophysical studies that image within and beneath the ice. This project will also include the opportunity to access and directly sample the base of ice sheet, providing critical observations where they are needed most. Ultimately, by constraining the role that water plays in ice sheet flow, this research will lead to better informed models, resulting in better estimates of sea level rise.