A team of US researchers from the University of California, Irvine and NASA’s Jet Propulsion Laboratory have noticed a never-before-seen way in which ice and the ocean interact with each other. A discovery that could increase dissolution projections by 200%.
Glaciologists have in fact stated that, the data obtained while conducting a study on the glacier Petermann in northwest Greenland, they could prove that the climate community has largely underestimated the magnitude future sea level rise caused by the deterioration of polar ice.
According to the article published on “Proceedings of the National Academy of Sciences”thanks to the use of satellite radar data from three European missions, the UCI/NASA team understood that the Petermann ground line, where the ice is released from the earth’s bed and then floats towards the ocean, moves substantially during the tidal cycles, thus allowing thewarm sea water to seep into and melt the ice at an accelerated rate.
Dr Enrico Ciraci, UCI specialist in Earth System Sciences and lead author of the study, said: “The grounding line of the Petermann Glacier it migrates between 2 and 6 kilometers as the tides roll in and out. This is an order of magnitude larger than expected, hardening our conception of glacial melt.”.
In fact, previous knowledge of land lines under glaciers reaching the ocean did not predict them moving even during tidal cycles, nor did they contemplate melting of the ice. This new study shows instead that warm ocean water seeps under the ice through subglacial channels pre-existing, with the highest melting rates occurring in the root zone.
The researchers also found that when the groundline of the Petermann Glacier retreated nearly 4 kilometers between 2016 and 2022, warm water seeped into the interior. creating a cavity of over 200 meters at the bottom of the glacier. A “cave” that has remained unchanged throughout 2022.
Prof. Eric Rignot, professor of Earth System Sciences at UCI and a researcher at NASA JPL, as well as a senior co-author of the study, explained: “These ice-ocean interactions make the glaciers more sensitive to ocean warming. Unfortunately, however, these dynamics have not been included in the predictive models, otherwise, they would increase the sea level rise projections by up to 200%”.
By the way, do you know what would happen if all the glaciers melted? A danger that should not be underestimated, also considering that the melting of the polar ice is deforming the planet.