A new find in the antartida suggests that this continent is vulnerable to submarine landslides due to global warming, which could trigger gigantic tsunamis in south america and other areas of the southern hemisphere.
The study, published on May 18, 2023 in the journal Nature Communications, details that drilling was carried out on the Antarctic seabed to extract sediments and analyze them.
Thus, they discovered that in ancient times of global warming, layers of loose sediment formed and slipped, generating huge tsunami waves off the coasts of South America, Southeast Asia and New Zealand.
“Submarine landslides are a significant geological hazard with the potential to trigger tsunamis that can cause great loss of life,” Jenny Gales, professor of hydrography and ocean exploration at the University of Plymouth in the United Kingdom, said in a statement.
“Our findings highlight how we urgently need to improve our understanding of how global climate change could influence the stability of these regions and the potential for future tsunamis.”
According to the study, during the times when the analyzed sediments were formed (3 million and 15 million years ago), the waters around Antarctica were 3 °C warmer than today, which caused the spread of algae that, after dying, filled the seabed with a rich, slippery sediment. That made the region prone to landslides.
“During cold climates and subsequent ice ages, these slippery layers were covered by thick layers of coarse gravel spewed up by glaciers and icebergs,” Robert McKay, director of the Victoria University of Wellington’s Center for Antarctic Research and co-director, told LiveScience. expedition scientist who extracted the sediments in 2018.
From global warming to giant tsunamis
According to the authors, the most likely cause of the submarine landslides was melting ice from glaciers due to warmer weather. During these epochs, the ice sheets contracted and receded, lightening the load on Earth’s tectonic plates and causing them to bounce upward. A process known as isostatic rebound.
With the weak sediment layers accumulated in sufficient quantities, the continental rise of Antarctica triggered earthquakes which caused coarse gravel on slippery layers to slide off the edge of the continental shelf. This caused landslides that ended in tsunamis.
In this sense, the researchers warn that, if their hypothesis is correct, the current thaw due to global warming could cause new submarine landslides in Antarctica, so that tsunamis of great proportions would occur again.
However, they emphasize that they handle other hypotheses to explain the landslides. For example, a fault in the tectonic plates or changes in ocean currents that erode sediments. “It’s something we could test in future studies using computer models,” MacKay concludes.