The Thwaites Glacier Tongue
Thwaites Glacier in Antarctica could be one of the biggest dominoes our planet has seen since the asteroid that ended the dinosaurs over 60 million years ago.
This hunk of ice at the bottom of the world is roughly the same size as Britain or Florida. New research from an international team studying the glacier suggests it could completely collapse by the end of this decade if not sooner, triggering a potentially catastrophic chain of events.
“Thwaites is the widest glacier in the world,” said Ted Scambos, a senior research scientist at the Cooperative Institute for Research in Environmental Sciences (CIRES). “The glacier in its entirety holds enough water to raise sea level by over two feet. And it could lead to even more sea-level rise, up to ten feet, if it draws the surrounding glaciers with it.”
There’s been less than a foot of sea level rise since 1900, and that has been enough to increase flooding in some coastal communities. Ten feet of sea level rise would redraw maps around the world. And this could be a conservative estimate.
Ella Gilbert, Postdoctoral Research Associate in Climate Science at the University of Reading writes for the Conversation that the loss of Thwaites could also trigger the collapse of newly exposed ice cliffs into the ocean in West Antarctica, ultimately causing “several meters” of sea-level rise.
“A sea level rise of several meters would inundate many of the world’s major cities – including Shanghai, New York, Miami, Tokyo and Mumbai,” Gilbert writes. “It would also cover huge swathes of land in coastal regions and largely swallow up low-lying island nations like Kiribati, Tuvalu and the Maldives.”
Experts from the International Thwaites Glacier Collaboration presented their work earlier this month at the American Geophysical Union virtual meeting. It shows three factors driving the Thwaites eastern ice shelf towards collapse by 2030.
The portion of the glacier that hangs over the ocean is being melted from beneath by warming sea water, while the entire structure is losing its grip on an underwater seamount that helps hold it back from flowing out to sea.
“But before it fully looses its grip on the seamount, this eastern ice shelf is likely to shatter into hundreds of icebergs just like the shattering of your car’s window,” explained Erin Pettit in a presentation at the conference.
Pettit added that scientists have already seen fractures propagating across the shelf by up to several miles a year.
The collapse of the Thwaites Glacier and the worst case scenario chain reaction is not guaranteed, however. Other recent research has suggested chunks of ice that break off the glacier will help arrest further collapse.
“But while uncertainty remains about exactly what will happen in West Antarctica,” concludes Gilbert. “One thing is for sure – the retreating Thwaites glacier will continue to add to global sea levels for many years to come.”
Source by www.forbes.com