Wednesday, January 24, 2018

Interacting Antarctic Glaciers May Cause Faster Melt and Sea Level Contributions

New research shows the Thwaites Glacier in Antarctica, pictured here, may be at risk of melting further inland than previously thought. (Credit: NASA) Click to Enlarge.
A new study shows that a large and potentially unstable Antarctic glacier may be melting farther inland than previously thought and that this melting could affect the stability of another large glacier nearby -- an important finding for understanding and projecting ice sheet contributions to sea-level rise.

The findings, by a Stanford-led team of radar engineers and geophysical glaciologists, came from radar data collected at the same locations in 2004, 2012 and 2014, each revealing details of the glaciers miles below the surface.  The surveys show that ocean water is reaching beneath the edge of the Pine Island Glacier about 7.5 miles further inland than indicated by previous observations from space.

The team also found that the Southwest Tributary of Pine Island Glacier, a deep ice channel between the two glaciers, could trigger or accelerate ice loss in Thwaites Glacier if the observed melting of Pine Island Glacier by warm ocean water continues down the ice channel. The results were published online in the Annals of Glaciology.

"This is a potentially really dynamic place between these two glaciers, and this is somewhere where further study is really warranted," said lead author Dustin Schroeder, an assistant professor of geophysics at the School of Earth, Energy & Environmental Sciences. "If this tributary were to retreat and get melted by warm ocean water, it could cause the melt beneath Pine Island to spread to Thwaites."

Sea-level rise has become a major concern in recent years based on research showing extra ocean water from melting glaciers could swamp coastal areas around the world, contaminate drinking and irrigation water, threaten wildlife populations and hurt the economy. This new perspective on the Southwest Tributary shows melting beneath Pine Island may be currently or imminently causing the melting of Thwaites and speeding the rate of sea-level rise.

"These results show that the ocean is really starting to work on the edge of this glacier, which means that we're likely at the onset of it having an impact," Schroeder said.

Read more at Interacting Antarctic Glaciers May Cause Faster Melt and Sea Level Contributions

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