The climate crisis is causing ice in Antarctica to melt faster than at any other time in recorded history. And scientists just found another troubling sign for Antarctic ice. Record warm water is surging under an Antarctica glacier that’s fate is intertwined with the millions of people who live along the coast. Needless to say, the results could be catastrophic.
The massive Thwaites Glacier slides down from the West Antarctic ice sheet into the Amundsen Sea, which part of the glacier floats over. It’s the most vulnerable glacier on the entire continent, and its collapse could be part of a chain of events that would cause seas to rise 10 feet. No wonder it’s nicknamed the doomsday glacier. Researchers have known for decades that it’s unstable, but a recent daring research expedition onto the ice has revealed for the first time that warm water have reached a particularly crucial location underneath it.
A team of 100 researchers from the U.S. and UK were deployed to the glacier in November as the first major expedition to Thwaites Glacier. The team fanned out across the ice in groups to do a variety of work, including capturing stunning video from under the ice. While out on the ice, another group drilled an almost 2,000-foot deep hole through ice to ocean below. The scientists then dropped a device that could sense temperatures and ocean turbulence down into the depth. They recorded water temperatures of about 0 degrees Celsius (32 degrees Fahrenheit). That’s more than 2 degrees Celsius (3.6 degrees Fahrenheit) warmer than that location’s freezing point owing the chemistry of saltier water.
The alarming readings were taken at the glacier’s “grounding line,” where the ice transitions between resting on bedrock and floating on the ocean. Thwaites has unfortunate under-ice topography where the bedrock slopes downward, allowing waters to cut deep under the ice. To make matters worse, the waters there were turbulent, which means the ocean’s saltwater and the glacial freshwater are mixing together. That turbulence may push the warm water toward the glacier, causing the ice to melt even faster. The finding “suggests that it may be undergoing an unstoppable retreat that has huge implications for global sea level rise,” David Holland, a glaciologist from New York University who performed the research, said in a press release.
Those rising sea levels won’t just affect the remote areas where the glaciers are melting. Communities up and down the world’s coasts would have to contend with the extra water pouring into the ocean.
Advertisement
“Warm waters in this part of the world, as remote as they may seem, should serve as a warning to all of us about the potential dire changes to the planet brought about by climate change,” said Holland.
The Thwaites Glacier spans 74,000 square miles, which is roughly the size of Florida, and it already contributes to four percent of global sea level rise. If it collapses, Thwaites alone would drain enough ice from the West Antarctic to raise global sea levels almost three feet.
Advertisement
But the effects could be even worse than that. Thwaites and another large glacier, the Pine Island Glacier, act as a brake on part of the West Antarctic Ice Sheet. Pine Island has a similar setup to Thwaites with bedrock sloping downward under the ice and warm water swirling beneath it. If they both melt, huge amounts of ice could break off and flow into the sea. That would cause the oceans to rise up to 10 feet, drowning many coastal cities.
It’s not clear exactly how fast the Thwaites will melt, but it is clear that the climate crisis is accelerating the process. And that’s dangerous for many parts of the world because what happens in Antarctica doesn’t stay in Antarctica.
Advertisement
https://news.google.com/__i/rss/rd/articles/CBMiXmh0dHBzOi8vZWFydGhlci5naXptb2RvLmNvbS9zY2llbnRpc3RzLW1ha2UtZmlyc3QtZXZlci1vYnNlcnZhdGlvbi1vZi13YXJtLXdhdGVyLXVuLTE4NDE0Mjg2MTXSAWJodHRwczovL2VhcnRoZXIuZ2l6bW9kby5jb20vc2NpZW50aXN0cy1tYWtlLWZpcnN0LWV2ZXItb2JzZXJ2YXRpb24tb2Ytd2FybS13YXRlci11bi0xODQxNDI4NjE1L2FtcA?oc=5
2020-02-03 17:06:00Z
52780584570805
Tidak ada komentar:
Posting Komentar