Western Antarctica Ronne Shelf Ice long lasted a warm time
Modis / Zuma wire / shutterstock
An important ice sheet of Antarctica seems to last more than 120,000 years ago, as we thought that the collapse of the western Antarctic ice sheet is not a collapse created as a result of climate change. could raise the sea level. But there are great uncertainty.
“It’s good news and they are bad news,” he says Eric Wolff University of Cambridge, United Kingdom. “We didn’t get the worst case. But I can’t put your hand in my heart and say that he wouldn’t happen in the next century.”
Human climate change does not have the future of the western ice sheet without sure. If we continue to emit high levels of greenhouse gases, some models projects will disappear completely in the coming centuries. In 2023, in extreme scenarios projected by climate change in climate change, this could increase the level of 2100 meters of 2 meters.
Wolff and his colleagues looked at Ronne’s humble ice, a large section of the ice sheet that extends in the ocean to see how it was played between 117,000 and 126,000 years ago. At the time, this is Last time interglacialChanges in Earth Orbits are exacerbated by Antarctic temperatures than today.
To determine the modest ice ice in that warm time, researchers measured the concentrations of sea salt in a 650-kilometer-drilled ice nucleus. If the humble ice had melted during the last clump, he would attract his edges closer to the location of the nucleus. As a result, researchers would be expected in the core of salt concentrations during those years, because the location of the nucleus would be much closer from the open ocean. “It would be a coastal resort,” Wolffer says.
Instead, they found salt concentrations in the latest interglacials were similar or smaller than today, indicated that the edge of the ice sheet was kept far away. Other measurements of water isotopes, which are preserved by weather models that affect the changing ice sheet, also lasted the last interglacial of the Ronne Ice.
This warm-term temperature suggests ice stability, that Antarctic ice sheet will completely collapse when climate change drives global temperatures, as Wolff says. However, he and other researchers said the sea ice still has a high risk of melting.
“It assumes that the full desglacement of the western Antarctica, but it doesn’t give us enough information to relax,” he says Timothy Naish New Zealand at Victoria University.
For joint, ronne shelf survival does not mean other areas of ice, like Thwaites or Pine Island GlaciersIt didn’t melt. In fact, the water isotope record believes Wolff says Wolff. The researchers used also used the ice nucleus that did not cover the hottest period of interglacials.
The latest interglacial dynamics of the most varied in the region is also global warming today temperatures are rising throughout the planet. For example, warm ocean water that arrives in Antarctica can speed up the ice under the ice, Wolff.
“It’s really important observation, but I think it will take us longer to figure out what it means,” he says Andrea Dutton At the University of Wisconsin-Madison. The researchers emphasized that they spend 50 years ago trying to work on what happened to the west Antarctic ice sheet during the last club.
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