How explosives, robots and sleds exposed the apocalyptic ice​​

But the news from Icefin does not bode well. Seawater warm enough to melt the glaciers hovered around Thwaites’ ground line (the exact point where the ice meets the land), which has receded more than a mile since 2011. This means that more seawater is now in contact with the bottom of the glacier, which means more melting. Washam said that ice “is the messiest part of all of this-it has these very cool corrugated, undulating features near the ground wire.” These features are hot spots of melting.

If the bottom of Thwaites is flat, the fresh water melted from the ice will collect under it like a lid, preventing it from being further melted by the warm sea water. “It basically prevents ocean heat from entering the ice,” Washam said. Conversely, the undulating, sloping features can break the lid of the fresh water, allowing the warm water to come into contact with the ice.

This discovery provides glaciologists with important insights into how glaciers around the world may be degrading—a factor they have not yet considered in their modeling. “This other way of melting along these sloping ice surfaces does not exist in ice sheet models,” Washam said. “This shows us that we must consider this if we are to predict the contribution of Antarctica to sea level rise more accurately.”

Lizzy Clyne, a geophysicist and glaciologist at Lewis and Clark College, and another conference host, discovered more problems in the pick-up area-by using explosives, the staff put the explosives into a 20-foot-deep hole in the ice middle. (“It’s a bit like fireworks,” Klein said. “It will hurt you if it explodes in your hands, but it’s not like a huge bomb.”) A series of seismometers on the surface measure the energy of the explosion from something under the ice Rebound. Using these data, Klein can see whether it is water or solid soil. Its working principle is similar to Pettit’s ground penetrating radar, in fact Clyne also combines seismic data with radar data.

Clyne has been collecting data since 2018 that shows that because Thwaites’ ice shelf partially floats on the surface, it will tilt as the tide enters and exits. As it rises, warm water slides across the land and under the ice sheet resting on land, pushing more melting. This is another key dynamic not reflected in glacier melting modeling. “In this case, you might pull the seawater above freezing point a few degrees further inland than we initially thought,” Klein said. “It may be like a few centimeters of water, with a thin layer extending inland. But that’s all it takes to melt the ice.”

Now scientists are piecing together these trends-cracks in ice shelves, complexity at the bottom of glaciers, and tidal pumps-they have made a severe assessment of the apocalyptic ice: it breaks down more ways than they understood before. . If it melts completely and takes away the surrounding glaciers, the sea level will rise by a total of 10 feet. “In my opinion,” Klein said, “if we are going to have a very rapid sea level rise in the next few decades, it cannot happen unless Thwaites makes a big contribution to it. “

By towing radars on sledges, driving torpedo robots and detonating explosives, scientists are building a clearer picture of the most important glacier on earth. “I personally do not have the ability to control sea level rise, nor can I solve the problem of global warming by myself,” Klein said. “But what we can do is to study and understand what is happening, what is going to happen, and how to reduce the impact as much as possible.”

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