Wednesday , November 25 2020

There is a six-mile hole in a West Indian glacier – quartz



Nobody likes a surprising vacuum. Especially not a vacuum where ice is supposed to be. Especially not in the glacier, which is already playing the greatest role as a single glacier in the ocean.

The cavity or "cavity" that radar researchers put it – lies in the Thwaites glacier, a cumbersome ice mass on the very cumbersome West Antarctic ice sheet. Melting from Thwaites is currently responsible for an estimated 4% of global sea level rise. It is before that expects the surprise cavity.

Scientists found the cavity thanks to ice radar linked to NASA's Operation IceBridge aircraft along with data from Italian and German Earth observation satellites. They released their results in Nature last week. The most disturbing aspect of the discovery is the large size of the empty space where ice must be and the fact that it only began to grow once between 2011 and 2016, suggesting that it is growing in an "explosive" rate according to one NASA Jet Propulsion Laboratory press release accompanies the paper.

The cavity is now about six miles long and 1000 meters long (300 meters) deep. The empty space represents the loss of about 14 billion. Tons is.

The size of the cavity is alarming because it contributes to a feedback loop of judgment – a death spiral to the glacier if you want: The larger the cavity, the more water can touch the glacier below, causing melting faster.

"This is the ocean that eats away on the ice," Eric Rignot, one of the study's authors and a professor of soil science at the University of California-Irvine, told the New York Times. "It is a direct influence on the climate change on the glacier."

The Thwaite glacier is a "threshold" system, which means that when it reaches a certain point in its crumbling, it will be destabilized. When destabilized, there is no return; It will fall apart. If Thwaites melt down completely – which models predict it is possible within 50-100 years, according to the NBC sea level, it may rise by two feet on average across the globe.

And if the Thwaites fall apart, it can trigger the destabilization of the rest of the West Caribbean ice sheet.

As Jeff Goodell put it in Rolling Stone, a complete collapse of Thwaites would be a doomsday scenario:

When a piece of ice is Pennsylvania's size falls apart, it's a big problem. It does not happen overnight, but if we do not lower the heating of the planet, it can happen within decades. And its loss will destabilize the rest of Western Antarctic ice, and it will also go. The oceans will rise about 10 meters in many parts of the world; In New York and Boston, due to the way gravity pushes water around the planet, the water will rise even higher, as much as 13 feet.

The prospect of a Thwaites collapse is scary enough for some scientists to suggest artificially clearing it up. In 2018, a couple of scientists presented the idea of ​​building an artificial herring-a kind of crutch – to hold it back, but also recognized that humanity's technological capabilities are probably not yet at that level. "An ice interference today would be on the edge of human abilities," they wrote. "The easiest design we considered could be compared to the largest civilian projects humanity has ever tried."


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