Antarctica's Oldest Ice Shelf Under Threat for 18,000 Years

By analyzing marine sediments and microfossils , it was possible to reconstruct 40 thousand years of exchanges and interactions between ice and ocean in Antarctica : this allowed us to discover that the ancient ice shelf in the Ross Sea , the largest on the planet , has been threatened by warming for 18 thousand years, after the end of the last ice age, due to the arrival of warmer waters beneath it. This is the result of the international study led by the Institute of Polar Sciences of the National Research Council of Bologna and the Ca' Foscari University of Venice, published in the journal Science Advances. The research, which is essential to understanding how the ecosystem will react to the impact of current climate change , also involved the Institute of Marine Sciences of the CNR, the National Institute of Geophysics and Volcanology and the University of Trieste. "This is the first direct evidence that the Deep Circumpolar Current , a marine current warmer than the typical Antarctic waters, and therefore capable of melting ice, managed to rise up to the base of the ancient floating ice shelf in the Ross Sea, contributing to its breakup at the beginning of post-glacial warming", says Chiara Pambianco of Ca' Foscari University and Isp-CNR, who coordinated the research. This shelf is particularly important because it acts as a link between sea ice and continental ice , and is therefore crucial for the stability of the Antarctic ice sheets . “The ancient platform was about 1,000 kilometers larger than it appears today,” adds Tommaso Tesi of Isp-Cnr, co-author of the study. “Understanding the dynamics that caused the reduction of this ancient platform in the past,” say Pambianco and Tesi, “is fundamental to predicting the future behavior of Antarctica in response to global warming and, consequently, how sea levels could change.”