Melting Antarctic Ice Formation May Trigger Unstoppable Sea-Level Rise
Yet another melting ice formation in Antarctica may dump so much water into the ocean that it could trigger an unstoppable rise in sea level for thousands of years to come, a new study published in Nature Climate Change revealed.
The current region threatening to raise our seas is the Wilkes Basin, the largest region of marine ice on rocky ground in East Antarctica. Currently, only a rim of ice at the coast holds the ice behind in place.
"East Antarctica's Wilkes Basin is like a bottle on a slant," said lead study author Matthias Mengel. "Once uncorked, it empties out."
The Antarctic air remains cold, but warming oceans can cause ice loss on the coast. Ice melting could make this relatively small cork disappear - and once that happens, it would trigger a long-term sea-level rise of 300-400 centimeters.
"The full sea-level rise would ultimately be up to 80 times bigger than the initial melting of the ice cork," added co-author Anders Levermann.
The mechanism behind melting Antarctica is the grounding line - the spot where the ice on the continent meets the sea and starts to float. The rocky ground beneath the ice forms a huge inland sloping valley below sea level.
Melting causes the grounding line to retreat, causing the rim of the ice facing the ocean to become higher than before. More ice is then pushed into the sea, eventually breaking off and melting. And the warmer it gets, the faster this happens.
Researchers say that based off of simulations, theoretically, the entire East Antarctica cork under speculation should take 5,000 to 10,000 years to melt. But once the melting process starts, there is no stopping it, even if climate warming stopped.
"This is the underlying issue here," said Matthias Mengel. "By emitting more and more greenhouse gases we might trigger responses now that we may not be able to stop in the future."