In the coming decades, sea level rise may accelerate more quickly than anticipated due to a massive flow of ice crawling out of Greenland's remote interior while also slowing down.
More than six times as much sea level rise as previously thought might occur globally by the end of the century due to the ice stream's degradation, researchers mentioned in a study published in Nature.
Northeast Greenland Ice Melting Faster
Researchers at Dartmouth College, the University of California, Irvine, and the Technical University of Denmark said that the largest basin of Greenland's ice is melting much more quickly than predicted by current climate models. It might increase the worldwide contribution to sea level rise by up to six times by 2100.
By the end of this century, the Northeast Greenland Ice Stream (NEGIS), equivalent to the contribution of the Greenland ice sheet during the preceding 50 years, may have raised sea levels by more than half an inch.
The study includes numerical modeling, satellite data, and GPS data collected over the next ten years from the complex interior of Greenland.
In 2012, the floating extension of the NEGIS collapsed due to the arrival of warm ocean currents, which worsened ice flow and sparked an upstream wave of rapid ice thinning, according to a statement.
The researchers found that numerous glaciers in the nation may suffer from the same issue. The thinning stretches 200-300 km (124-186 miles) inland from Greenland's coast.
Significant Factor in Sea Level Rise
Zachariae Isstrm's floating extensions disintegrated in 2012 after a decade of melting, and the glacier has subsequently been retreating inland more quickly. Additionally, the glaciers continue to recede despite the freezing winter of 2021 and summer of 2022. The ice sheet is not renewing enough to stop the melt since northeastern Greenland is a so-called Arctic desert with precipitation as low as 25 mm per year in certain areas. Calculating how much ice is lost and how far into the ice sheet the process takes place is difficult, though. Making precise estimates is challenging due to monitoring the ice sheet's interior, which changes less than one meter each year.
"Amazingly, we can detect a subtle speed change from high-precision GPS data, which ultimately when combined with a model of ice flow, inform us on how the glacier slides on its bed," said coauthor Mathieu Morlighem, a professor of earth sciences at Dartmouth College (per SciTechDaily).
He continued by saying that what was occurring in northeast Greenland may also be appearing in other areas of the ice sheet.
In recent decades, the thinning and acceleration of several glaciers along the boundary have increased. If the results are accurate, ice dynamics will affect Greenland's total mass loss more than current models predict.
The Zachariae Isstrm remained stable until 2004, after which the ice front gradually retreated until 2012, when a significant chunk of the floating portions detached. It is anticipated that the IPCC's predictions of a global sea level rise of 22-98 cm will need to be revised upward if more accurate measurements of the change in ice velocity are included in models.
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