Public Release: 

Greenland's ice sheet plumbing system revealed

Pioneering new research sheds light on the impact of climate change on subglacial lakes found under the Greenland ice sheet

University of Exeter

Pioneering new research sheds light on the impact of climate change on subglacial lakes found under the Greenland ice sheet.

A team of experts, led by Dr Steven Palmer from the University of Exeter, has studied the water flow paths from one such subglacial lake, which drained beneath the ice sheet in 2011.

The study shows, for the first time, how water drained from the lake - via a subglacial tunnel. Significantly, the authors present satellite observations that show that a similar event happened in 1995, suggesting that this lake fills and drains periodically.

The study, called Subglacial lake drainage detected beneath the Greenland Ice Sheet is published in the journal Nature Communications.

Lead author Dr Steven Palmer, from Geography at the University of Exeter, said: "Our research reveals details about the plumbing system beneath the Greenland ice sheet, which is important because the configuration of that system has an impact on the flow speed of the overlying ice."

Although the ice sheet response to draining subglacial lakes has previously been observed in Antarctica, this is the first time that a similar phenomenon has been observed in Greenland.

However, unlike Antarctic subglacial lakes, which are sustained through melting of the ice sheet base, the study shows that this subglacial lake has been fed by surface meltwater flowing down a nearby moulin - a circular, vertical shaft found within a glacier.

The scientists predict that as the Arctic continues to warm, increasing volumes of surface meltwater routed to the ice sheet bed will cause subglacial lake drainage to become more common in the future. Because the way in which water moves beneath ice sheets strongly affects ice flow speeds, this increased drainage frequency could affect the sensitivity of the ice sheet to climate change, impacting the rate of future sea level change.

Dr Palmer added: "We have made the first observations of how the Greenland ice sheet responds to subglacial lake drainage, but more research is required to understand the long-term impacts of these events. It is possible that draining subglacial lakes act to release the pressure at the ice sheet base, meaning that if they drain more frequently in the future, they may actually result in slower ice sheet flow overall".


For further information:

University of Exeter
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+44 (0)1392 722405 or 722062

About the University of Exeter

The University of Exeter is a Russell Group university that combines world-class research with very high levels of student satisfaction. Exeter has over 19,000 students and is one of the global top 100 universities according to the Times Higher Education World University Rankings 2015-16, positioned 93rd. Exeter is also ranked 7th in The Times and The Sunday Times Good University Guide 2016, 9th in the Guardian University Guide 2016 and 10th in The Complete University Guide 2016. In the 2014 Research Excellence Framework (REF), the University ranked 16th nationally, with 98% of its research rated as being of international quality. Exeter was named The Times and The Sunday Times Sports University of the Year 2015-16, in recognition of excellence in performance, education and research. Exeter was The Sunday Times University of the Year 2012-13.

The University has invested strategically to deliver more than £350 million worth of new facilities across its campuses in the last few years; including landmark new student services centres - the Forum in Exeter and The Exchange on the Penryn Campus in Cornwall, together with world-class new facilities for Biosciences, the Business School and the Environment and Sustainability Institute. There are plans for further investment between now and 2016.

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