A UK team of researchers has produced high-resolution maps of the bed beneath a major glacier in West Antarctica, which will help them predict future sea-level rise from this region. Radar surveys of the land beneath Pine Island Glacier have revealed a diverse landscape under the ice with some surprises. The results are published in the journal Nature Communications.

The Pine Island glacier in West Antarctica is one of the five largest ice streams of Antarctica. It is responsible for 25 percent of Antarctica’s ice loss and has the largest net contribution to of ice to the sea. Credit: NASA
The Pine Island glacier in West Antarctica is one of the five largest ice streams of Antarctica. It is responsible for 25 percent of Antarctica’s ice loss and has the largest net contribution to of ice to the sea. Credit: NASA

The findings are significant as Pine Island Glacier is the fastest melting glacier in Antarctica and currently accounts for up to 10 per cent of global sea level rise. Ice melting into the ocean in the region is expected to increase as the climate warms and the West Antarctic ice sheet continues to thin. The survey of the glacier, the most detailed to date, was carried out between 2013-2016 as part of the NERC funded iSTAR programme. Snow vehicles equipped with radar sensors surveyed about 1500 km2 of land, taking readings every few hundred metres. Lead author Dr Robert Bingham, of the University of Edinburgh’s School of GeoSciences, says: “Detailed understanding of this diverse landscape, and how that will impact on ice melt from one of Antarctica’s most important glaciers, will give us valuable clues as to how warming in this region will impact on global sea level.” The findings represent significant progress in the data available to inform forecasts of ice loss. Previous computer models used less comprehensive data from aerial radar surveys, which did not account for a range of ice bed shapes and the effects these could have on glacier friction.

The new survey pictures show a rugged and scarred landscape with mountains and deep troughs. According to the scientists, this will have a significant influence on the flow of the glacier. Credit: BAS
The new survey pictures show a rugged and scarred landscape with mountains and deep troughs. According to the scientists, this will have a significant influence on the flow of the glacier. Credit: BAS

Co-author Prof David Vaughan from British Antarctic Survey says: “These maps have revealed new features under Pine Island Glacier that we never thought were there. The bed turns out to be much rougher than we thought. There are mountains and deep scour marks which are clearly going to be influencing the flow and behaviour of the ice. In order to really understand how the glacier is going to respond to future change, we need to understand its interaction with the bed and these high resolution maps let us begin to do this.” The study shows that the diverse nature of the terrain beneath the glacier is the biggest factor affecting the flow of the ice across the landscape. Scientists will incorporate the new findings into computer models used to project the glacier’s future. Damon Davies, of the University of Edinburgh’s School of GeoSciences, who took part in the research, says: “Pine Island Glacier is a key contributor to sea level rise, so this major step forward in understanding its dynamics will help improve our predictions of ice melt into the ocean.”

The scientists and support staff spent 24h a day outside to map the glacier. The radar was towed behind skidoos over the glacier for the survey. Credit: Damon Davies
The scientists and support staff spent 24h a day outside to map the glacier. The radar was towed behind skidoos over the glacier for the survey. Credit: Damon Davies

Source: British Antarctic Survey