Antarctic glacial melt rate triples in Amundsen Sea embayment

Scientists analyzed 21 years of data from 1992-2003

Glaciers in the west Antarctic have tripled their melt rate over the past decade, a new study has found after scientists examined 21 years of data.

Glaciers in the west Antarctic have tripled their melt rate over the past decade, a new study has found after scientists examined 21 years of data. (NASA/Associated Press)

Glacial melt rate in a region of west Antarctica tripled over the past decade, a new study suggests.

Scientists from the University of California and NASA analyzed 21 years of data tracking how much ice glaciers in west Antarctica’s Amundsen Sea embayment lost from 1992 to 2003. The area is considered the fastest melting region in Antarctica.

“The mass loss of these glaciers is increasing at an amazing rate,” scientist Isabella Velicogna, a co-author of a published paper explaining the findings, said in a written statement.

The researchers found glaciers in the area lost a total average of 83 gigatons of mass per year. The researchers say this is the water weight loss equivalent of Mount Everest’s weight every two years.

That measurement accelerated about 6.1 gigatons annually during the period studied.

The scientists studied four sets of observations spanning 2003-09, including two data sets from NASA, as well as the European Space Agency and the University of Utrecht in the Netherlands.

During this time, scientists found the glaciers lost an average of 84 gigatons of mass and the melt rate increased 16.3 gigatons annually on average. This is “almost three times the rate of increase for the full 21-year period,” according to a statement announcing the results.

The paper was published in Geophysical Research Letters.

Oceanic heat transport onto the Amundsen Sea shelf through a submarine glacial trough

antarctic-through

Swath bathymetry showing the shelf break and the submarine glacial trough A non-linear color scheme is used to clearly show the trough features, and depths >1400 m are colored the same.

Hydrographic data measured across the glacial trough. (a) Temperature, (b) salinity, and (c) neutral density γn.

The white line is the upper limit of Circumpolar Deep Water (CDW) (γn = 28.00 kg m−3).

What it comes down to is that the glacier no longer reaches the bottom of a valley it sits on and this valley (trough) is being filled with “warm” ocean water. Warm in this case is about +1 degree C.

While the top layers of the glacier are in the -1.75C range the lower layers are about +0.5C

If this is your field of expertise please comment (at the bottom of the page) but right now what I’m understanding is that as the “warm” water melts the ice covering the trough from the bottom, the trough becomes bigger holding more warmer water and thus the acceleration in ice loss.

That’s my brief “book report” on a scientific paper based on 21 years of data.

But go ahead, read the Geophysical Research Letter yourself and then we’ll compare notes. BTW, you can get an App for your iPad from the iTunes store.

 

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