More Trouble at Totten Glacier
May 19, 2016
Today’s headline in the Washington Post is another illustration of why readers and viewers at this blog get some of the best early-warning info on the issues of climate.
My video above, “Trouble at Totten Glacier” discussed a little known, but important and unstable, part of the Antarctic ice sheet, with a key, but very young, scientist, Jamin Greenbaum. You saw it here first.
One more reason to support Dark Snow this year:
Scientists ringing alarm bells about the melting of Antarctica have focused most of their attention, so far, on the smaller West Antarctic ice sheet, which is grounded deep below sea level and highly exposed to the influence of warming seas. But new research published in the journal Nature Wednesday reaffirms that there’s a possibly even bigger — if slower moving — threat in the much larger ice mass of East Antarctica.
The Totten Glacier holds back more ice than any other in East Antarctica, which is itself the biggest ice mass in the world by far. Totten, which lies due south of Western Australia, currently reaches the ocean in the form of a floating shelf of ice that’s 90 miles by 22 miles in area. But the entire region, or what scientists call a “catchment,” that could someday flow into the sea in this area is over 200,000 square miles in size — bigger than California.
Moreover, in some areas that ice is close to 2.5 miles thick, with over a mile of that vertical extent reaching below the surface of the ocean. It’s the very definition of vast.
Warmer waters in this area could, therefore, ultimately be even more damaging than what’s happening in West Antarctica — and the total amount of ice that could someday be lost would raise sea levels by as much as 13 feet.
“This is not the first part of East Antarctica that’s likely to show a multi-meter response to climate change,” said Alan Aitken, the new study’s lead author and a researcher with the University of Western Australia in Perth. “But it might be the biggest in the end, because it’s continually unstable as you go towards the interior of the continent.”
The research — which found that Totten Glacier, and the ice system of which it is part, has retreated many times in the past and contains several key zones of instability — was conducted in collaboration with a team of international scientists from the United States, Australia, New Zealand and the United Kingdom. A press statement about the study from the U.S. group, based at the University of Texas at Austin, described the study as showing that “vast regions of the Totten Glacier in East Antarctica are fundamentally unstable.”
Finally, recent research has suggested that Totten can only lose a tiny 4.2 percent of its remaining ice shelf before the structure starts losing the ability to brace the larger glacier, holding it in place. It all points to a region of enormous vulnerability, and one that is already undergoing change.
The radar, magnetic and gravity measurements conducted in the study found key regions where Totten Glacier and the connected systems of ice behind it lie atop plenty of sediment — suggesting the glacier retreats rapidly in these areas. But it also detected areas where there isn’t much sediment at all, suggesting that it grinds away in these locations a great deal, or in the words of UT-Austin’s Jamin Greenbaum, one of the researchers behind the study, is able to “ping-pong back and forth” over long time periods.
More here on Antarctica, and the instability of the West Antarctic Sheet.
and here, a portion of the key interview with Glaciologist Eric Rignot that left myself, John Cook, and Dr. James Byrne, peeling our jaws off the floor, in December of 2014.