As the oceans get warmer, sediment slippages under the seabed of Antarctica could foster massive and destructive tsunamis.
Tsunamis in Antarctica?
Per Live Science, scientists have found out that in earlier global warming periods, around 15 million and 3 million years ago, loose layers of sediment ended up forming and slipping. These enabled strong tsunamis to surge over Southeast Asian, New Zealand, and South American shores. The scientists discovered this by drilling sediment cores situated hundreds of feet below the Antarctic seafloor.
Now, as climate change worsens and affects global waters, the scientists think that these tsunamis could be unleashed once again over Antarctic waters. They noted their findings in the Nature Communications journal.
If they were to happen, these strong waves could leave major infrastructures devastated, such as subsea cables, the Pacific Daily News reports. This may lead to economic turmoil and significant casualties thousands of miles from where they originated.
Dr. Jenny Gales, a hydrology and ocean exploration lecturer from the University of Plymouth in the UK, explains that submarine landslides are serious geohazards that may potentially facilitate life-threatening tsunamis. Dr. Gales adds that their findings stress the urgent need to know more about how climate change may affect how stable these regions are and the possibility of tsunamis happening in the future.
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Climate Change in Ancient Antarctica
Initial evidence of landslides in Antarctica was first found in 2017 in the eastern Ross Sea. Weak sediments and phytoplankton were found to be trapped beneath such landslides.
The scientists then revisited the area in 2018 and drilled under the seabed in order to have sediment cores extracted. By examining them further, they discovered that these weak sediment layers formed in two distinct prehistoric periods, namely, 3 million years ago and 15 million years ago. During these times, Antarctic waters were just 5.4 degrees Fahrenheit warmer than their present temperature. This led to algal blooms bursting that filled the seabed below with slipper and rich sediments after they died. This, in turn, made the area prone to landsliding.
Robert McKay, the co-chief scientist of the International Ocean Discovery Program Expedition 374 and the director of the Antarctic Research Center at Victoria University of Wellington, explains that in the subsequent cold weather and ice ages, such slippery layers were overlain by thick, coarse gravel layers that icebergs and glaciers brought.
Though the precise trigger behind earlier underwater landslides remains unknown, researchers have pinpointed the potential culprit with the highest likelihood: glacier ice melting due to global warming.
Live Science reports that after the buildup of weak sediment, the continental upspringing of Antarctica triggered strong earthquakes that caused landslides that eventually unleashed massive tsunamis.
While the exact scale remains a mystery, researchers have noted two submarine landslides that are relatively recent and that triggered strong tsunamis and led to significant life loss. These were the Grand Banks Tsunami in 1929 and the Papua New Guinea tsunami in 1998.
Considering the sediment layers buried under the seabed of Antarctica and the melting of glaciers, the researchers caution that landslides and tsunamis could take place once more. McKay adds, however, that the huge question lies in whether this trigger is still in play. Future studies may examine it further.
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