Every week brings a new climate discovery. This week it is an under glacier body of water that COULD raise current sea levels by seven metres. As is always the case, everything is predicated on so many variations that could or might or is conceivable. Well, if the moon turned blue it might not be pale yellow or blood red. While you’re wait for that to happen call in a builder to raise your house at least seven metres, or more if the next warning comes with a new discovery.
Scientists using seismic testing at the largest glacier in east Antarctica find massive subglacial lakes beneath its surface — which they say radically alters estimates on predicted sea level rise. A team of international researchers from the Australian Antarctic Program have this week returned from a 160-day expedition at the Totten Glacier, located near Casey Station — about 3,431 kilometres (2,132 miles) from Hobart.
Antarctic mission reveals Totten Glacier secrets, along with rethink on sea level rise
Glaciologist Dr Ben Galton-Fenzi said in order to find out what was underneath, researchers drilled into the ice sheet and set off small explosives about two metres below the surface of the glacier, which is up to 30 kilometres wide and up to two kilometres thick.
“These explosions sent out sound waves, which then echoed off different layers in the ice and bedrock,” he said.
“We place geophones along the surface of the glacier to listen to the reflected sound, giving us a picture of what lies beneath the ice.”
The methodology led to the discovery of a network of lakes beneath the ice.
Dr Galton-Fenzi said “a substantial amount of water” was contained in the subglacial lakes, which could impact the rate at which ice flows into the ocean.
“In the context of climate change, we need to understand the characteristics of the bed, because they exert a very powerful control over the flow of the glacier,” he said.
PhD student Madi Gamble Rosevear said the speed at which the Totten Glacier travels was determined by what it moved across.
“As the glacier flows over the land, the properties underneath it control how quickly it flows,” she said.
“So, if there’s soft sediment or water it can slide quite quickly, or if it’s dry, tough rock it’s quite sticky and ice can slide quite slowly.”
While the Intergovernmental Panel on Climate Change (IPCC) estimates sea levels will rise by a metre by 2100, Dr Galton-Fenzi said those estimates did not factor in the increased discharge of Antarctic ice due to climate change.
“The Totten Glacier drains an area of east Antarctica that contains about seven metres of sea level rise equivalent of ice,” he said.
“If I took all the ice contained in the catchment, spread it out over the global oceans, sea levels would go up seven metres.
“We actually know for a fact that the Totten Glacier is one of the regions that’s actually changing.
“We know there’s warm water present under the glacier, so we expect this is one of the regions in east Antarctica that’s going to change first.”