Judging by this photo, elephant seals are not the sorts of creatures you'd rely on to glide nimbly beneath Antarctic ice gathering scientific data about melting glaciers. But that's precisely what they'll be doing. They may be anything but athletic on land, but elephant seals are the picture of agility in the water, capable of swimming vast distances and diving to great depths as they forage for food. So, in addition to technologies like ground-mapping radar and ice-tracking probes, scientists will be calling upon the seals' services to help them figure out how melting glacier ice is contributing to rising sea levels around the globe.
The British Antarctic Survey (BAS) scientists are heading for the Pine Island Glacier in the Amundsen Sea as part of a £7.4 million study into why the ice stream is thinning at such a rapid rate. Known as the PIG, the glacier contributes to global sea level rises more than any other (it's responsible for an increase of between 1mm and 2.5mm over the past ten years).
“We used to think that the volume of water flowing from Antarctica’s melting glaciers and icebergs into the ocean was equal to the amount of water falling as snow onto the ice sheet; and that this process was keeping the whole system in balance. But Pine Island and Thwaites glaciers on the West Antarctic Ice Sheet (WAIS) are losing ice at a faster rate than they are being replenished. This affects sea level all over the world. The speed of changes to this region has taken scientists by surprise and we need to find out what’s going on,” says the research programme's Dr Andy Smith.
So how do seals fit into this glacier-tracking mission? In an effort to get the most comprehensive picture of the glacier possible, scientists are tackling the task from a number of different perspectives – and they're hoping the seals will provide data other equipment can't. That state-of-the-art equipment includes a fleet of ocean robots known as Seagliders, as well as specially designed 'snow tractors' that will carry researchers hundreds of miles across the glacier as they map the underlying bedrock with ground-based radar and seismic technologies.
The seals' turn will come during the Antarctic winter, when the ice-covered ocean surface is inaccessible to research ships. Scientists plan to attach small temperature and salinity sensors to the fur of 15 seals, allowing them to collect data that will be transmitted back to laboratories via satellite. In addition, the information will help scientists to better understand how the animals are coping with the effects of a changing climate. And never fear ... the sensors are designed to be temporary and will eventually fall off when the seals moult.
