Antarctic study to help understand climate change

Researchers from Edinburgh University are preparing for a study based in the Antarctic, which is hoped to provide a long-term perspective on natural climate change. During the trip scientists will analyse ancient rocks that have been embedded in the West Antarctic Ice Sheet in order to determine if it melted 120,000 years ago and caused sea levels to rise by six metres.

Professor Andy Hein of the University of Edinburgh's School of GeoSciences told The Journal: “The most important part of this study is to determine if possible whether or not the West Antarctic Ice Sheet melted during the last interglacial period". Professor Hein described his role in the study and said he will be responsible for “mapping and interpreting the geomorphology of the nunataks and to sample rocks for surface exposure dating.

"Back in Edinburgh," he continued, "I will manage the chemical preparation of the rock samples for measurement of multiple cosmogenic nuclides at the Accelerator Mass Spectrometry facility at the Scottish Universities Environmental Research Centre in East Kilbride. I will interpret the exposure age results and their implications for the history of the West Antarctic Ice Sheet.”

Scientists hope to find out whether the sheet did in fact melt in between the two ice ages, by using special sensory technology to measure the rocks’ exposure to cosmic radiation whilst they had been emerged from the ice. Professor Hein added: “Our last project focused on ice-elevation changes in the Shackleton Range of Antarctica. During this project we expected to find that the Slessor Glacier, a major glacier that drains the East Antarctic Ice Sheet into the Weddell Sea, had thickened greatly during the last ice age.

"Instead, we found that this glacier was not much thicker than it is today. This surprising result has several implications. For example, it implies the volume of ice that was locked up in the Antarctic Ice Sheet during the last ice age was significantly less than previously thought, and therefore this part of the ice sheet contributed less to sea-level rise following the last ice age.”

More traditional techniques will also be used in the study as Professor Hein said: “Our co-investigator John Woodward of Northumbria University will use a wide range of new and traditional geophysical technology during this study. This will include ice-penetrating radar, GPS, terrestrial laser scanners and remote-controlled aircraft carrying camera equipment.

"The aim of this part of the research is to produce high resolution digital elevation models of the nunataks where the exposure dating will be carried out, and to understand the formation mechanisms of blue-ice moraines. For the exposure dating we will use geochemistry procedures to extract rare isotopes of beryllium, aluminium, chlorine and neon to assess the long-term history of these blue-ice areas.”

Professor Hein believes the study “will provide a long-term perspective on natural climate change in Antarctica. This will help to put modern observations into their longer-term context.”

Research will begin in 2013 and last three years, and is funded by the Natural Environment Research Council in collaboration with the Universities of Northumbria and Exeter, the Scottish Universities Environmental Research Centre, the University of Cologne and the British Antarctic Survey.