More of one of Antarctica’s largest and most important glaciers is floating on top of the ocean than previously thought, researchers say, which could have a significant impact on the rise of global sea levels.
The new research from the Australian Antarctic Program has found the Totten Glacier, located in the southern continent’s east, could be affected more by warming ocean temperatures because more of the glacier is directly in contact with the ocean, and much less is sitting on rock than originally thought.
“The Totten is actually one of the most important glaciers in Antarctica, and you might even argue the world, because it drains a region of the Antarctic ice sheet that could lead to several metres of potential sea level [rise] in the future”, he said.
“The amount of ice sitting behind the Totten is comparable to that which is contained within the whole West Antarctic ice sheet.”
Dr Galton-Fenzi’s team of researchers included scientists from Australia and overseas, with Professor Paul Winberry joining from Central Washington University in the United States.
Professor Winberry said the new information was obtained by using seismic technology.
“We use seismic methods. They’re very similar to how the oil companies might explore for oil underneath the earth,” he said.
“So we try to generate soundwaves, they go down, and we hear echoes coming from big discontinuities inside the Earth.”
These methods allow researchers to determine how thick the ice is, as well as how thick the ocean column is underneath the ice.
Antarctic researchers estimate the glacier itself holds enough ice to raise global ocean levels by around three metres if it were melted in its entirety.
“The Intergovernmental Panel on Climate Change [IPCC] estimates of future sea levels by 2100 suggests that there’s going to be about a metre of sea level [rise] through thermal expansion of the oceans, that’s atmospheric heat going into the oceans causing them to warm where they expand,” Dr Galton-Fenzi said.
“But also there’s a contribution of the Antarctic ice sheet — and the Greenland ice sheets actually — so as they melt that ice mass flows into the oceans and causes a further increase in sea levels.
“So when you think about that one metre that the IPCC have suggested by 2100, which is significant, next to this idea that the Totten Glacier catchment contains the potential for three metres of sea level [rise].
“…then that’s an incredibly high number, and it’s a region that we really need to understand how soon its going to change to warming climate and how soon its going to cause sea levels to rise.”
Dr Galton-Fenzi says it was too early to understand what the consequences of these findings would be, but he said that any increase in ocean temperature meant that the glacier would likely be affected.
The researchers flew down to Casey Station in Antarctica in early December last year, and spent about eight weeks on the southern continent while investigating the glacier.
Despite the seriousness of the research, Professor Winberry said Antarctica was not a bad place to spend Summer.
“[It was] brilliant … most days there was a high above freezing!” he said.