Antarctic glacier retreats almost 3 miles, could foreshadow huge sea level rise

Rodiano Bonacci
Marzo 28, 2020

Sea levels worldwide could go up almost five feet, researchers say.

A December examination discovered that the trough beneath Denman Glacier goes 3,500 meters under sea degree, making it the planet's deepest land canyon.

Denman Glacier in East Antarctica has retreated three miles over a 22-year period, but researchers are concerned that its demise could just be beginning and a total meltdown would cause global sea levels to rise a whopping 5 feet (1.5 m).

Between 1979 and 2017, the glacier experienced a cumulative mass loss of 268 billion tonnes of ice, according to the study, released Monday.

A visualization of the deep trough below East Antarctica's Denman Glacier.

Scientists have just found a new vulnerability in the Antarctic ice sheet, in a region where there appears to be a climatic change towards warm and has the potential to raise the levels of the sea by almost five feet over a long term.

Scientists have been more concerned about western Antarctica, where ice has melted faster in recent years, Rignot said.

Researchers closely examined Denman's grounding line - the point at which ice leaves land and starts to float in the ocean - using radar interferometer data from the Italian Space Agency's COSMO-SkyMed satellite system.

Denman's eastern flank is protected from exposure to warm ocean water by a roughly 6-mile-wide (10-kilometer-wide) ridge under the ice sheet.

The UCI and NASA JPL scientists report in the Geophysical Research Letters paper that the bed configuration of Denman is unique in Antarctica's eastern sector.

"Because of the shape of the ground beneath Denman's western side, there is potential for the intrusion of warm water, which would cause rapid and irreversible retreat, and contribute to global sea level rise in the future", said lead author Virginia Brancato, a scientist at JPL.

It's going to be essential to trace the 24,000-sq. -kilometer floating extension of Denman Glacier, which incorporates the Shackleton Ice Shelf and Denman ice tongue, Rignot mentioned.

Co-author Eric Rignot, an earth system science professor at UCI, said they will keep an eye on the glacier even as much anxiety is focused on the other side of the continent. This subsea is a trough that is more than 2 miles deep.

This project was funded by NASA's Cryosphere Program and received support from the Italian Space Agency and the German Space Agency. Data and bed topography maps are publicly available at DOI: 10.15146/zf0j-5m50.

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