One of the largest glaciers in Antarctica, Pine Island, is irreversibly melting due to volcanic activity recently discovered by scientists.
The study published in the journal Nature Communications, allows us to understand how the ice sheet of the western part of Antarctica works and its relationship with climate change.
How was the discovery
In 2014, a multi-month expedition to Antarctica aimed at testing different noble gases present in dehilee water, accidentally found high concentrations of Helium-3, an indicator of volcanic activity.
“We were looking to better understandthe role of the ocean in melting the ice shelfor, ”said Brice Loose, a chemical oceanographer at the University of Rhode Island, who authored the study in a statement. “I was analyzing the water to measure five different noble gases, including helium and xenon. Use these noble gases to track ice melting and heat transport. Helium-3, the gas that indicates volcanism, is one of the gases that we obtained from this tracking method. "
Although the finding seemed a mistake to the scientists, the situation was not entirely strange since the West Antarctic ice sheet sits on top of a major system of volcanic crevasses located under many kilometers of ice.
When you find helium-3, it's like a fingerprint from volcanism. We found it to be relatively abundant in seawater on the Pine Island shelf, ”says Loose.
“Helium Isotope Measurements and noble gases provide geochemical evidence for the production of subglacial meltwater that is subsequently transported to the Pine Island ice shelf cavity "
So far no magmatic activity had been detected. The last activity of this kind was 2,200 years ago. And what the scientists found on Pine Island was new.
The causes of glacier melt
Pine Island has been going back almost 80 years, a trend that has been more pronounced since 1992 and that is related to climate change.
Pine Island is the fastest losing mass in Antarctica, but Loose cautions that this does not imply that volcanism is the main cause. On the contrary, "there are several decades of research documenting the heat from ocean currents destabilizing the glacier, which in turn appears to be related to a change in the climatological winds around Antarctica," he clarifies. Mind you, new evidence for volcanism is a new factor to consider when monitoring ice sheet stability. According to scientists, the heat source under Pine Island can be about 25 times greater than most of the heat flux from an individual dormant volcano.
As Karen Heywood, a professor at the University of East Anglia in Norwich, UK, and chief scientist on the expedition explains, 'the discovery of the volcanoes beneath the Antarctic ice sheet means that there is an additional source of heat to melt the ice. , lubricate its passage to the sea, and add it to the warm waters of the ocean. It will be important to include this in our efforts to estimate whether the Antarctic ice sheet may become unstable and further increase sea level rise. '
Does that mean that global climate change is not a factor in the stability of the Pine Island Glacier? No, says Loose. "Climate change is causing most of the glacial melt that we observe, and this recently discovered heat source is having an effect yet to be determined, because we do not know how this heat is distributed beneath the ice sheet."
As the scientists explain, predicting the rate of sea level rise is going to be a key role for science in the next 100 years, and for this scientists must know these glaciers perfectly.