By drilling into sediment cores hundreds of feet below the Antarctic sea floor, scientists have discovered that during previous periods of global warming, between 3 million and 15 million years ago, loose sediment layers formed and slid to send massive tsunamis racing to the shores of South America. New Zealand and Southeast Asia.
As climate change heats up the oceans, scientists believe there is a potential for these tsunamis to be unleashed again, according to Live Science.
“Undersea landslides pose a significant geographic hazard that could lead to tsunamis that could lead to massive loss of life,” Jenny Gales, Lecturer in Marine Surveying and Ocean Exploration at Plymouth University in the UK, said in a statement. The urgent need to enhance our understanding of how global climate change affects the stability of these regions and the possibility of future tsunamis.”
Scientists first found evidence of ancient landslides off Antarctica in 2017 in the eastern Ross Sea.
Beneath these landslides are layers of weak sediment crowded with fossilized marine organisms known as phytoplankton.
Scientists returned to the area in 2018 and dug deep into the sea floor to extract sediment cores, which are long, thin cylinders of the Earth’s crust that show, layer by layer, the geological history of the area.
By analyzing the sediment cores, scientists learned that the weak sediment layers formed during two periods, one about 3 million years ago in the middle of the warm Pliocene, and the other about 15 million years ago during the Miocene climate.
During these ages, the waters around Antarctica were 5.4 degrees Fahrenheit (3 degrees Celsius) warmer than today, triggering algal blooms that filled the sea floor below with rich, slippery sediment, making the area vulnerable to landslides.
“During subsequent cold climates and subsequent ice ages, these slippery layers were covered by thick layers of coarse gravel that were carried by glaciers and icebergs,” said Robert Mackay, director of the Antarctic Research Center at Victoria University of Wellington and chief scientist.
He added: “The same layers are still present on the outer continental shelf, so it is poised for more of these slides to occur, but the big question is whether the trigger for the events is still there.”
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