Antarctic Seals Help Scientists Track Melting Ice Sheet
Scientists studying the warming waters and salinity of the Southern Ocean's Amundsen Sea—which surrounds the Thwaites and Pine Island glaciers, two of the largest and fastest-retreating glaciers in Antarctica—are using a novel method to collect data.
They temporarily glued sensors onto the fur of Antarctic seals. Really.
Instead of using research vessels, which are unable to traverse through the region's thick sea ice during winter, the researchers tagged seven southern elephant seals and seven Weddell seals with devices that can record the waters' warmth and salinity and send this data back via satellite.
The project is a collaboration between scientists at the University of East Anglia (UEA) and the Sea Mammal Research Unit at the University of St. Andrews in the UK.
"These tiny sensors, which are temporarily glued to the animals' fur and fall off during molting, will allow us to collect essential oceanographic observations during the winter time, as well as providing a better indication of how vulnerable the seals might be to climate change," Lars Boehme of Sea Mammal Research Unit told The Scotsman.
According to a press release, the seals were able to collect measurements as they moved around the region and dived from the surface of the ocean down through the water to the sea bed during hunts for food.
Over a period of nine months, the team collected data from more than 10,000 dives in over an area of 93,000 square miles.
The project aims to help climate modellers make more accurate predictions about how rapidly the Western Antarctic ice sheet is melting, which could significantly add to global sea level rise. The region contains enough ice to raise global sea levels by an estimated 4 feet.
Notably, the new findings show that the Amundsen Sea's layer of circumpolar deep water—a relatively warm (about 2°C) water mass blamed for destabilizing the continent's ice shelves—is thicker, warmer and saltier in the winter than during the summer.
The research was published Tuesday in the journal Geophysical Research Letters.
Thwaites and Pine Island are two of the fastest receding glaciers on the Western Antarctic Ice Sheet. The region contains enough ice to raise global sea levels by 4 feet.
"We knew very little about what to expect from this research, since this is the first time that data has been collected in this way in this area," said Helen Mallett, who led the study at UEA, in a statement.
"We were able to collect much more information from the seals than all the previous ship-based surveys in the area combined and it was clear that, at least during the seasons we observed, there were substantial differences in temperature between the seasons."
Mallett added, "Although more will need to be done to measure these differences over a number of years, it's clear that enlisting seals to collect this kind of ocean data will offer useful insights for climate change modellers who are attempting to predict how fast sea levels will rise."