Thinning ice has caused bedrock deposits underneath Antarctica to rise higher than ever before, a new study published in the journal Science reports.
As the ice melts, it takes the weight off the bedrock below. Though that process does not happen right away, large amounts of ice have melted across Antarctica through the years. That in turn caused the bedrock to rise up in response.
This new finding — which comes from researchers at the Technical University of Denmark — is both good and bad news.
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It is good news because the uplift of supporting bedrock may help anchor other ice sheets and make them more stable. However, the rising rock has likely skewed past satellite measurements on ice loss and those predictions may be underestimated by as much as 10 percent.
Though computer models help scientists understand how the Earth’s mantle behaves, they do not have a full idea of the different reactions that drive its mechanisms. These findings are a good example of such processes, and they could shed more light on the geological movements of our planet.
“The study of this — the distribution of viscosity in the mantle — is still in its infancy,” said lead study author Valentina Barletta, a postdoctoral researcher at DTU Space, the National Space Institute at the Technical University of Denmark, according to Live Science. “We know where the Earth is hotter and cooler — more or less. However, the viscosity of the mantle depends not just on temperature, but also on water content.”
While scientists previously believed changes like the ones in the recent study took tens of thousands of years, the newly documented process occurred over decades. That suggests the mantle under Antarctica may flow more quickly than previously suspected.
To measure those changes, the team installed six GPS stations at locations around a region of the ice sheet known as the Amundsen Sea Embayment (ASE). They placed the monitors at exposed bedrock and gathered data at a spatial resolution of 0.6 miles.
That revealed the rising bedrock.
The team hopes this new information will be incorporated into models and help inform future decisions.
“These data will be of great value to the modeling community who examine the complex relationships between GIA, sub-ice shelf ocean circulation, and ultimately, ice sheet stability,” said Doug Kowalewski, the Antarctic Earth Sciences program director in the National Science Foundation’s Office of Polar Programs (OPP) who was not involved in the research, according to Phys.org.