Antarctica’s grounding lines are retreating across the seafloor. The Southern Ocean melted 565 square miles of underwater ice between 2010 and 2016.
And this new study provides clear evidence that retreat is happening across the ice sheet due to ocean melting at its base. But please don’t forget that recent discoveries have revealed just how volcanic Antarctica really is, despite being hidden underneath massive ice sheets.
Why is Antarctica ice melting?
The grounding lines of Antarctica are on the retreat on the ocean floor. According to a new study, warm ocean water is shrinking Antarctica’s underwater footprint.
Antarctica’s glaciers have been retreating at an average rate of 82 feet per year. But the rate retreat of the grounding lines of eight of the ice sheet’s 65 largest glaciers is five times greater, roughly 410 feet per year. The most dramatic rates of grounding line retreat were measured along the coast of West Antarctica.
“Our study provides clear evidence that retreat is happening across the ice sheet due to ocean melting at its base, and not just at the few spots that have been mapped before now,” lead researcher Hannes Konrad said. “This retreat has had a huge impact on inland glaciers, because releasing them from the sea bed removes friction, causing them to speed up and contribute to global sea level rise.“
And what about the volcanoes in Antarctica?
But please scientists! Don’t forget that recent discoveries have revealed just how volcanic Antarctica really is, despite being hidden underneath massive ice sheets.
Back in August 2017, scientists discovered 91 volcanoes under Antarctica ice but it wasn’t sure if they were active or not.
Now, in November 2017, a new heat source was discovered under Antarctica driving ice melt and volcanism.
A few days after this discovery, the British Antarctic Survey (BAS), had revealed a new Antarctic heat map showing sub-ice hotspots across the icy continent and thus representing the ‘geothermal heat flux’ at the base of the Antarctic Ice Sheet.
Ocean melting surely plays a role in this epic ice melting phenomenon, but this source of heat is not as hot and dramatic as the heat released by those hot spots and volcanoes situated under the thick ice mantle of Antarctica. [Nature]