Gigantic Seafloor Valleys Discovered Beneath West Antarctica Glaciers

Posted: Jan 19 2017, 2:48am CST | by , Updated: Jan 19 2017, 3:50am CST, in News | Latest Science News

 

Gigantic Ocean Valleys Discovered Beneath West Antarctica Glaciers
West Antarctica glaciers observed during October 2014. Credit: NASA / Michael Studinger
 

The valleys could accelarate the melting of some of the some of biggest glaciers in West Antarctica

Geologists have uncovered large valleys in the seafloor underneath some of the massive glaciers of West Antarctica. The valleys lurking inside the ocean floor are putting fragile glaciers at an increased risk of melting from the below as they are paving the way for warm, salty water to reach the undersides of the glaciers.

The discovery was made by measuring the sea ice motion of some of the massive glaciers like Pine Island, Thwaites, Smith and Kohler. University of California, Irvine’s own mass conservation algorithm provided exquisite details of sea-ice thickness, shape and other physical features that are essential for understanding changes in sea-ice mass balance, interactions between sea floor and glaciers and for predicating their response under warming climate.

Researchers combined the information with gravity data collected by airborne NASA Operation IceBridge missions from 2009 to 2014 to generate comprehensive maps of oceanic troughs below ice sheets in West Antarctica. This high-resolution maps of the ocean floor enabled researchers to detect a deep cavity beneath the Pine Island Glacier and a shallow trench beneath Thwaites Glacier.

“These oceanic features are several hundreds to a thousand meters deeper than what we thought before,” said lead researcher Romain Millan from University of California, Irvine. “It gives new insight into the future fate of these glaciers and the potential influence of warm ocean water that can melt away ice from below.”

The most important findings were the gigantic valleys under the Crosson and Dotson ice shelves that drop 1,600 feet beneath Crosson and 2,500 feet beneath Dotson and could contribute to accelerate submarine ice melting in Smith, Pope and Kohler glaciers.

Not only does the mapping provide a clearer picture of troughs hiding beneath the glaciers of vulnerable sector of West Antarctica but also make us aware of the threats associated with it. These oceanic features could lead to the collapse of entire Amundsen Sea Embayment region of Antarctica which contains both Thwaites Glacier and Pine Island Glacier. If this happens, it would cause additional 4 meter rise in global sea levels.

“We've revealed that West Antarctic glaciers include natural pathways for water intrusion, but all water sources are controlled by a 700-meter-deep sill which blocks access to the truly warmest waters," said Eric Rignot, co-author of the study. 

“This is good news in terms of having these glaciers not fully exposed, but it makes the projections more challenging because all tiny details will be important in controlling ocean heat access to the glaciers."

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Hira Bashir covers daily affairs around the world.

 

 

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