While its nickname — the “doomsday glacier” — never exactly inspired optimistic feelings, it looks like West Antarctica’s Thwaites Glacier is even more urgently dangerous than we previously thought.
According to a new study published on September 5 in the journal Nature Geoscience, the glacier (which is huge — about the size of Florida), has the potential to retreat even faster than we previously thought, which could be disastrous for rising sea levels.
As part of the study, which was led by marine geophysicist Alastair Graham at the University of South Florida’s College of Marine Science, scientists mapped a critical area of the seafloor in front of the glacier in order to determine a window of how fast the glacier retreated and moved in the past. While the imagery reveals more about the glacier’s historical behaviour, it also offered insight into what the future may hold — and that’s what’s so scary.
The scientists found that at some point in the past 200 years (and over a period of time of less than six months), the front of the glacier dislodged from the seabed ridge and retreated quickly — at a rate of more than 2.1 kilometres per year. This rapid rate is twice the rate documented by satellites between 2011 and 2019.
“Our results suggest that pulses of very rapid retreat have occurred at Thwaites Glacier in the last two centuries, and possibly as recently as the mid-20th Century,” Graham said in a press release.
According to Popular Science, the Thwaites Glacier already accounts for four per cent of the Earth’s annual global sea level rise, and it has the potential to raise sea levels by approximately three-to-10 feet if it melts.
“Thwaites is really holding on today by its fingernails, and we should expect to see big changes over small timescales in the future – even from one year to the next – once the glacier retreats beyond a shallow ridge in its bed,” marine geophysicist and study co-author Robert Larter from the British Antarctic Survey said in the release.
Though scientists can’t predict the exact rate and timeline for the glacier’s changes, the study does reveal the possibility of rapid changes to Antarctic ice sheets.
“Just a small kick to Thwaites could lead to a big response,” Graham said.