Home / Science / The Antarctic ice sheet melts to a higher than expected sea level.

The Antarctic ice sheet melts to a higher than expected sea level.

A Harvard study indicates that the Antarctic ice sheet will cause sea levels to rise more than previously thought.

This picture was taken in the Scotia Sea during the 2007 campaign.Credit: Michael Weber.

The global sea level rise associated with a possible collapse of the West Antarctic ice sheet was significantly lower than in previous studies, meaning that sea level The warming world is higher than expected, according to a new study by Harvard researchers.

The report is published in Scientific breakthroughNew calculations are made for what the researchers refer to as the ejection mechanism. This happened when the hard shale of the West Antarctic Ice Sheet sits on a rebound as the ice melts and the total weight of the ice sheet decreases. The rock is located below sea level, so as it lifts, it pushes water from its surroundings into the ocean, raising the global sea level.

The new forecasts show that in the event of all ice sheet erosion, projections of global sea-level rise will expand by another meter within 1

,000 years.

“The magnitude of the impact shocked us,” said Linda Pan, PhD. In the field of Earth and Planetary Sciences at GSAS, who led the study in collaboration with fellow graduate student Evelyn Powell, “a previous study that considered the mechanism abolished this study was negligible.”

“If the West Antarctic Ice Sheet collapses, the most widely cited forecast of the global average sea level rise, which will result in 3.2 meters,” Powell said. “What we’ve shown is that the water drive mechanism adds an additional meter 1 meter, or 30 percent of the total.”

But this is not just a story about the impact that will be felt in hundreds of years. One of the simulations at Pan and Powell has shown that by the end of the global sea level rise caused by the melting of the West Antarctic Ice Sheet, there will be a 20 percent increase by the water drive mechanism.

“All sea level rise forecasts published due to the melting of the West Antarctic Ice Sheet are based on climate models, whether forecasts extend towards the end of this century or longer.” That in the future will have to be modified to be higher because From their work, ”said Jerry X. Mitrovica, a Frank B. Baird Jr. professor of science at the Department of Earth and Planetary Sciences and senior author, in this paper,” Everyone. “

Pan and Powell, both researchers in Mitrovica’s lab, began this research while working on another sea level change project. But switched to the project when they noticed more water was draining from the West Antarctic Ice Sheet than they had expected.

The researchers wanted to investigate how repulsion mechanisms influence sea level changes when determining the low viscosity or the easy-flowing material of the mantle of western Antarctica. By incorporating this low viscosity into the calculations, they realized that the ejection of the water occurred much faster than the previous model had expected.

“Regardless of the circumstances of the West Antarctic ice sheet collapse, we often find that one meter of sea level rise occurs,” Pan said.

The researchers hope that their calculations will show that, to accurately estimate the global sea level rise associated with melting ice sheets, scientists need to combine both water-repellent and low-viscosity effects. Of the mantle under Antarctica

“Sea levels don’t stop when the ice stops melting,” Pan said. “The damage we do to our shoreline will continue for centuries.”

Antarctica’s impact on sea level rise over the next several centuries.

More information:
“The rapid post-ice recovery has boosted global sea levels after the West Antarctic Ice Sheet collapsed.” Scientific breakthrough (2021). DOI: 10.1126 / sciadv.abf7787

Provided by Harvard University

Reference: Antarctic ice sheets melt to raise sea levels higher than previously thought, study states (2021, April 30) .Retrieved May 1, 2021 from https://phys.org/news/2021-04-antarctic-ice-sheet-. sea-higher -thought.html

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