The biggest glacier in East Antarctica is melting due to warm ocean water

If the Totten glacier melts, global sea levels will rise by 3.5 meters

If the Totten glacier melts, global sea levels will rise by 3.5 meters

The massive Totten glacier, despite being in one of the world's most remote locations in east Antarctica, is melting due to global warming. Scientists on Australia's Aurora Australis icebreaker ship confirmed the satellite data which were showing that the glacier was thinning fast. In January 2015, thanks to an opening in the sea ice, the ship managed to get in closer than before, allowing precise observations. They took ocean measurements at 10 separate points along the floating Totten ice shelf, only to find out that warm water in the area "exceeds the in situ freezing point by more than 2.2°C", leading to the thinning of the glacier. The "warm" water is still below freezing point, but at the depths where the melting is occurring, this temperature is still warm enough to melt the basal ice. The research was published in Science Advances earlier this month.

"We discovered a large channel in front of the western side of the Totten Glacier which is around 10 km wide and up to a kilometer deep," said Dr Steve Rintoul, lead author of the report and Interim Director of Australia’s Commonwealth Scientific and Industrial Research Organization (CSIRO). "We found that warm ocean water is reaching the ice shelf through this channel, with temperatures high enough to drive rapid melt of the underside of the ice shelf." The measurements affirmed that warm ocean water is flowing in towards the glacier at the rate of 220,000 m³/second, causing the Totten to lose 63-80 billion tonnes each year to basal melt. This is the highest melt rate of any large East Antarctic ice shelf and one of the highest (if not the highest) on the whole continent. Although the glacier is hundreds of meters thick at points, it seems that the warm water is melting several meters of thickness per year.

‘The Totten is a big glacier, the largest in East Antarctica, and it contains enough ice to raise global sea levels by about 3.5 meters if it all melted, so it is important to know how it will behave in the future’, Dr Rintoul said. But apart from that, Totten could help researchers explain the phenomenon of radical sea level rise that occurred during previous warm eras, when global temperatures were not that much higher than those that exist today.