http://www.nationalgeographic.com/magazine/2017/07/antarctica-sea-level-rise-climate-change/
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www.nationalgeographic.com
Seen from above, the Pine Island Ice Shelf is a slow-motion train wreck. Its buckled surface is scarred by thousands of large crevasses. Its edges are shredded by ...
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I just got through reading the Nat. Geo. article link to above. Lee gets the actual paper based magazine. The web article includes the glorious photography that is typical for their work. More importantly it includes data that suggests risks that are much worse than the prior somewhat sanguine IPCC reports. Some quotes from the article:
The water there has warmed by more than a degree Fahrenheit over the past few decades, and the rate at which ice is melting and calving has quadrupled.
“These are the fastest retreating glaciers on the face of the Earth,” says Eric Rignot, a glaciologist at the NASA Jet Propulsion Laboratory in Pasadena, California. Rignot has studied the region for more than two decades, using radar from aircraft and satellites, and he believes the collapse of the West Antarctic Ice Sheet is only a matter of time.
During their five weeks of studying it, the ice under their boots thinned by another seven feet.
The west side of the Antarctic Peninsula is warming several times faster than the rest of the planet. Ninety percent of its 674 glaciers are now in retreat and are calving more icebergs into the sea,...
By measuring the amount of this freshwater, the researchers could estimate how much ice was being lost. The melt rates “were just crazy,” says Adrian Jenkins, a glaciologist from the British Antarctic Survey in Cambridge. According to his calculations, the ice shelf was losing 13 cubic miles of ice per year from its underside; back near the grounding line, the ice was probably thinning up to 300 feet per year.
“It was just beyond our concept that a glacier would melt that fast,” Jenkins says.
Average annual temperatures on its west side have risen nearly 5 degrees Fahrenheit since 1950—several times faster than the rest of the planet—and the winters have warmed an astonishing 9 degrees. Sea ice now forms only four months a year instead of seven.
Between 2002 and 2009 alone, the ice shelf in front of the Smith Glacier thinned by 1,500 feet in some places, the one in front of the Pope Glacier by up to 800 feet.
mapping with ice-penetrating radar has revealed a low-lying region cut by glacially carved channels that drop as far as 8,500 feet below sea level—perfect for guiding warm ocean water deep into the heart of the ice sheet. The Totten Glacier is the largest coastal outlet in this region. If it collapsed, global sea level could rise 13 feet—“roughly as much as all of West Antarctica,” Rignot points out. “One glacier alone.”
This is not carefully aggregated science. However, for several very massive glaciers that had been sitting firmly on the ocean bottom we now have warm salty ocean water sliding under them and melting many cubic miles of ice.
Don