Climate change could trigger gigantic deadly tsunamis from Antarctica, new study warns

An artist's illustration of a tsunami wave poised to crash down upon a beach.
An artist's illustration of a tsunami wave poised to crash down upon a beach. (Image credit: Shutterstock)

Climate change could unleash gigantic tsunamis in the Southern Ocean by triggering underwater landslides in Antarctica, a new study warns. 

By drilling into sediment cores hundreds of feet beneath the seafloor in Antarctica, scientists discovered that during previous periods of global warming — 3 million and 15 million years ago — loose sediment layers formed and slipped to send massive tsunami waves racing to the shores of South America, New Zealand and Southeast Asia. 

And as climate change heats the oceans, the researchers think there's a possibility these tsunamis could be unleashed once more. Their findings were published May 18 in the journal Nature Communications.

Related: Widening chasm births Antarctic iceberg larger than Los Angeles

"Submarine landslides are a major geohazard with the potential to trigger tsunamis that can lead to huge loss of life," Jenny Gales, a lecturer in hydrography and ocean exploration at the University of Plymouth in the U.K., said in a statement. "Our findings highlight how we urgently need to enhance our understanding of how global climate change might influence the stability of these regions and potential for future tsunamis."

Researchers first found evidence of ancient landslides off Antarctica in 2017 in the eastern Ross Sea. Trapped underneath these landslides are layers of weak sediment crammed with fossilized sea creatures known as phytoplankton. 

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

By analyzing the sediment cores, the scientists learned that the layers of weak sediment formed during two periods, one around 3 million years ago in the mid-Pliocene warm period, and the other roughly 15 million years ago during the Miocene climate optimum. During these epochs, the waters around Antarctica were 5.4 degrees Fahrenheit (3 degrees Celsius) warmer than today, leading to bursts of algal blooms that, after they had died, filled the seafloor below with a rich and slippery sediment — making the region prone to landslides. 

"During subsequent cold climates and ice ages these slippery layers were overlain by thick layers of coarse gravel delivered by glaciers and icebergs," Robert McKay, director of the Antarctic Research Centre at Victoria University of Wellington and co-chief scientist of International Ocean Discovery Program Expedition 374 — which extracted the sediment cores in 2018 — told Live Science in an email. 

The exact trigger for the region's past underwater landslides isn’t known for sure, but the researchers have found a most-likely culprit: the melting of glacier ice by a warming climate. The ending of Earth’s periodic glacial periods caused ice sheets to shrink and recede, lightening the load on Earth’s tectonic plates and making them rebound upwards in a process known as isostatic rebound. 

After the layers of weak sediment had built up in sufficient quantities, Antarctica’s continental upspringing triggered earthquakes that caused the coarse gravel atop the slippery layers to slide off the continental shelf edge — causing landslides that unleashed tsunamis.

The scale and size of the ancient ocean waves is not known, but the scientists note two relatively recent submarine landslides that generated huge tsunamis and caused significant loss of life: The 1929 Grand Banks tsunami that generated 42-foot-high (13 meters) waves and killed around 28 people off Canada’s Newfoundland coast; and the 1998 Papua New Guinea tsunami that unleashed 49-foot-high (15 m) waves that claimed 2,200 lives.

With many layers of the sediment buried beneath the Antarctic seabed, and the glaciers on top of the landmass slowly melting away, the researchers warn that — if they’re right that glacial melting caused them in the past — future landslides, and tsunamis, could happen again.

"The same layers are still present on the outer continental shelf — so it is 'primed' for more of these slides to occur, but the big question is whether the trigger for the events is still in play." McKay said. "We proposed isostatic rebound as a logical potential trigger, but it could be random failure, or climate regulated shifts in ocean currents acting to erode sediment at key locations on the continental shelf that could trigger slope failure. This is something we could use computer models to assess for in future studies."

This story was provided by Live Science.

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Ben Turner
Live Science Staff Writer

Ben Turner is a U.K. based staff writer at Live Science. He covers physics and astronomy, among other topics like weird animals and climate change. He graduated from University College London with a degree in particle physics before training as a journalist. When he's not writing, Ben enjoys reading literature, playing the guitar and embarrassing himself with chess.

  • Atlan0001
    *** Warning *** Repeating the Biblical 'Deluge', Noah's flood from the Bible, is religion as science, and science as religion. Environmentalism is a paganistic religion more ancient than even every major religion today recognized as such. And it isn't the Civilized State being repeated today as future history. It is very much the Savage State repeating in Mankind's (in Earth Life's) Iron Curtain imposed isolation from the 'High Frontier' and a new, latest, version of 'Exodus'.

    It, the new 'Noah's Arks' of the next 'High Frontier' (the High Seas and Hyper-Surface of Space Frontier), a new version of Biblical 'Exodus', is being withheld from "All Mankind" in every possible way a ruling totalitarian tyrannical / anarchic Orwellian Big Brother savage state can find to withhold it.
    Reply
  • billslugg
    Flood myth in the Bible is likely the catastrophic filling of the Black Sea ~6kya as glaciers melted and Bosporus was breached. Intact dwellings found on sea bottom attest to this.
    Parting of the seas most likely northern Red Sea flats becoming exposed due to stalled low pressure system in eastern Mediterranean Sea producing strong NNW winds over an extended period of time.
    Reply
  • Atlan0001
    billslugg said:
    Flood myth in the Bible is likely the catastrophic filling of the Black Sea ~6kya as glaciers melted and Bosporus was breached. Intact dwellings found on sea bottom attest to this.
    Parting of the seas most likely northern Red Sea flats becoming exposed due to stalled low pressure system in eastern Mediterranean Sea producing strong NNW winds over an extended period of time.
    Yes, I've read about the first in my readings of history, including having read about the opening of the Mediterranean basin at the Pillars of Hercules to becoming a sea. Talk about a tsunami, that had to be one heck of an awesome in-pouring.

    The second part about the Red Sea parting is, as far as I can tell from my own studies of history, a mythical turning of a very different human event into a natural event in the retelling of the story again and again, Egyptian columns recounting historical events of Pharaonic Egypt nowhere mention such an event. But they do recount the event at about that time of a great invasion and war they just barely finally won against a tremendous horde of the Sea Peoples of the Mediterranean. As I see it, they were so heavily engaged against the one horde that the Hebrew slave horde had their chance, saw their chance, and bolted Egypt. The Sea People horde, heavily engaged against the Egyptians parted their ranks and let the very large Hebrew Horde pour through and go away, meanwhile closing ranks behind them to re-engage the pursuing Egyptians and wiped that particular force out. In the retelling and retelling of the legendary escape, the parting of the Sea Peoples to let them through became just the parting of the Sea, the sea (rather than the sea peoples) closing up behind to destroy their pursuers. It made a better legendary story tied closer, more tightly, into their religion than being just let through by another warring horde -- invading from the sea -- going in the other direction.
    Reply
  • markm
    And the Arctic will be ice free by 2013!
    Reply
  • twr
    Best is, to stop space exploration, stop satellites and that all writers for space.com stop promoting space science, which „pollutes“ the athmosphere and changes the climate,and quit their jobs . Deal?

    Or you get rid of such nonsense writers and cult followers like Turner and concentrate on real sciences.
    Reply
  • murgatroyd
    What is an ink-stained wretch to do when the entire "mainstream" and all who aspire to belong are fully converged on the Climate Cult? The choice is between drawing a meager paycheck from SciAm, PMSNBC, space.com etc. etc. (until replaced by "artificial intelligence", which works for free) or submitting your honest, non-corrupt writings to alternative media, which however can only afford to pay a pittance (or nothing at all).

    As long as the powers that be maintain their iron grip on the taxpayer's pocketbook and public opinion, and thereby get to decree that "the science is settled" and you must fall in line or suffer the consequences ... nothing will change.
    Reply
  • Bill Hancock
    Atlan0101 said:
    *** Warning *** Repeating the Biblical 'Deluge', Noah's flood from the Bible, is religion as science, and science as religion. Environmentalism is a paganistic religion more ancient than even every major religion today recognized as such. And it isn't the Civilized State being repeated today as future history. It is very much the Savage State repeating in Mankind's (in Earth Life's) Iron Curtain imposed isolation from the 'High Frontier' and a new, latest, version of 'Exodus'.

    It, the new 'Noah's Arks' of the next 'High Frontier' (the High Seas and Hyper-Surface of Space Frontier), a new version of Biblical 'Exodus', is being withheld from "All Mankind" in every possible way a ruling totalitarian tyrannical / anarchic Orwellian Big Brother savage state can find to withhold it.
    First of all, every climate prediction that has ever been made by the United Nations has been patently false and has never ever come to pass. We did not slide back into an Ice Age recently and the climate science probably should be tossed into a category of pseudoscience. Secondly, if you wanna talk about the Bible, you probably might consider that there’s also another aspect of the Bible. It is also a history book. It has been proven to be historically accurate over and over. Almost every culture on the entire planet has a flood narrative. Painting with a broad brush and discrediting something by pointing to religion is equivalent to ad hominem attacks. Let’s just stick to facts. So tired of emotional arguments. Any ambitious person can get funding, and published for that matter, as long as they’re willing to tell you the sky is falling and mankind is causing global warming. Let’s not take into consideration what’s happening in space around us, considering this is a space.com website. There can literally be in numerable extraneous variables coming at our planet from the outside to affect climate, but who’s looking? And even if they are looking, who’s getting published? And who’s going to be able to spend a lot of time looking without funding? There’s no political will to learn the truth. There’s only political will to support a narrative that’s already been established. Science is becoming more and more of a religion. You can’t even go against the orthodoxy without being canceled.
    Admin said:
    Slippages in sediment beneath the Antarctic seabed could spawn gigantic tsunamis as oceans warm.

    Climate change could trigger gigantic deadly tsunamis from Antarctica, new study warns : Read more
    Well if you’ve done any reading you know the climate has always been changing. Earth future is never certain. As our solar system is travelling through our galaxy and our galaxy is travelling through the universe, anything can change, and anything can happen. It’s important to acknowledge that every climate disaster prediction that has been made in the 20th century and 21st century has been bogus. First they told us there was going to be an Ice Age. Big panic, let’s spread soot all over the north pole so maybe we can warm up the planet!. And it’s global warming global warming! Now it’s climate change climate change!. I was very little when I first heard the story about the boy who cried wolf. Hasn’t anybody learned yet? These disasters associated to climate change are becoming laughable.
    Reply