Climate change could trigger deadly tsunamis, new study warns

Climate change could trigger giant and deadly tsunamis in the Southern Ocean, a new study warns. An international team of scientists has found that global warming millions of years ago may have led to undersea landslides that caused massive tsunamis that reached the coasts of South America, New Zealand and Southeast Asia. As the oceans warm due to climate change, there is a chance that tsunamis will occur again, the international research team warns.

“Undersea landslides are dangerous and can cause deadly tsunamis,” said Jenny Gales, a lecturer in hydrography and ocean exploration at the University of Plymouth in the UK.

Drilling into sediment cores hundreds of meters below the sea floor in Antarctica has shown that millions of years ago there were landslides in the area caused by warming oceans. Researchers first discovered evidence of ancient landslides off Antarctica in 2017 in the eastern Ross Sea. Trapped beneath these landslides are layers of sediment filled with fossilized sea creatures known as phytoplankton.

Scientists returned to the site in 2018 and drilled deep into the sea floor to extract sediment cores – long, thin cylinders of the Earth’s crust that show, layer by layer, the region’s geological history.

The team then analyzed the cores and found that the sediment layers formed during two periods, one about 3 million years ago during the Pliocene warm period and the other about 15 million years ago during the optimum Miocene climate. During these periods, the waters around Antarctica were 3 degrees Celsius warmer than today, leading to bursts of algal blooms. When these died, they created a rich and slippery sediment – ​​making the area prone to landslides.

Scientists do not yet have a definitive answer as to the cause of the underwater landslides in the area, but they estimate that they may be due to melting ice. The end of Earth’s ice ages caused the glaciers to shrink and retreat.

Climate change could trigger deadly tsunamis, new study warns
The scale and size of ancient ocean waves are not known, but scientists note two relatively recent undersea landslides that generated massive tsunamis and caused significant loss of life: The 1929 Grand Banks tsunami that generated waves 13 meters high and killed about 28 people in coast of Newfoundland, Canada – and the 1998 Papua New Guinea tsunami that generated 15m waves and killed 2,200 people.

Layers of sediment buried beneath the Antarctic floor and melting glaciers could trigger landslides and tsunamis in the future.

“The same layers are still present on the outer continental shelf – so it is ‘primed’ for more such landslides to occur. but the big question is whether the trigger for the events is still there,” Robert McKay, director of the Center for Antarctic Research at Victoria University of Wellington and co-scientist of the International Ocean Discovery Program mission — which exported the sediment cores in 2018.

The study’s findings have broader implications, highlighting the importance of scientific ocean drilling and marine geology in understanding past climate change and identifying areas at risk of natural hazards. The researchers also highlight the need for comprehensive studies to assess the risks posed by submarine landslides along Antarctica and inform infrastructure planning.

The findings of the study were published in the scientific journal Nature Communications.

Source: ertnews, Live Science