Thu. Jan 27th, 2022


But the news from Isfin is not good. Warm enough water to melt the glacier is swirling around the grounding line at Thoites – the exact point where the ice meets the ground – and this line has been more than a mile behind since 2011. That means there is now more seawater in contact with the bottom of the glacier, which means more melting. “Ice is the most chaotic part of all of this,” said Washim, adding that it has corrugated, uncomfortable features near the grounding line. These features melt hot spots.

When the lower part of the thighs is flat, the fresh water melted from the ice will pool under it like a lid, preventing it from being further melted by warm seawater. “It will basically fight the heat movement of the ocean in ice,” Washam said. Instead, the sloping, sloping properties disrupt the freshwater lid, allowing warm water to contact the ice.

This revelation gives critics of glaciers a critical insight into how glaciers can be depleted everywhere এবং and a factor they have not yet considered in modeling. “There’s no other way of this kind of melting along the surface of this sloping ice in ice sheet models,” Washam said. “What it shows us is that this is something that should be considered if we are to project Antarctica’s contribution to sea level rise more accurately.”

Lizzie Klein, a geophysicist and ice scientist at Lewis and Clark College, and another conference presenter, found more problems in the grounding zone – using explosives, which crew descended into a 20-foot-deep hole in the ice. (“It’s like a kind of fireworks,” Klein said. “If it explodes in your hand it will hit you, but it’s not like a giant bomb.” Using that data, Klein can see if it’s water or solid earth. It acts like Petit’s ground-penetrating radar, and in fact, it also mixes clean seismic data with radar data.

View of the Isfin at the bottom of the Thwaites Glacier

Video: Peter Washam

Data that Klein has been collecting since 2018 shows that the ice sheets portion of the Thwaites is floating on the ocean, so it tilts in and out of the tide. As it rises, the warm water that is resting on the ground, through the grounding zone and beneath the ice sheets, melts even more. This is yet another critical dynamic that is not represented in the modeling of glacier melting. “It’s got the kind of activity where you’re dragging that twin-degree-above-frozen sea water a little farther inland than we initially thought,” Klein said. “It could be like a few centimeters of water, with a slightly thinner layer moving inward. But that’s all it takes to melt the ice. ”

Now that scientists are combining these trends – cracks in ice sheets, the complexity of glacier bottoms and tidal pumping – they have landed on a horrific assessment of the Doomsday Glacier: it is understood to be decomposing in more ways than they did before. If it melts completely and carries with it the surrounding glaciers, the sea level will rise a total of 10 feet. “In my view,” Klein said, “if we’re going to see sea levels rise too fast in the next few decades, that wouldn’t happen unless the Twitches contribute a lot.”

Pulling radar on sleds, driving torpedo robots and placing explosives, scientists are creating a perpetually-transparent image of the world’s most important glaciers. “I personally don’t have the ability to control sea level rise, and I can’t fix global warming on my own,” Klein said. “But all we can do is study and understand what is happening, what is going to happen and how to mitigate as much as possible.”


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