UNIVERSITY OF PLYMOUTH
Scientists have discovered the cause of giant underwater landslides in Antarctica which they believe could have generated tsunami waves that stretched across the Southern Ocean.
An international team of researchers has uncovered layers of weak, fossilised and biologically-rich sediments hundreds of metres beneath the seafloor.
These formed beneath extensive areas of underwater landslides, many of which cut more than 100metres into the seabed.
Writing in Nature Communications, the scientists say these weak layers – made up of historic biological material – made the area susceptible to failure in the face of earthquakes and other seismic activity.
They also highlight that the layers formed at a time when temperatures in Antarctica were up to 3°C warmer than they are today, when sea levels were higher and ice sheets much smaller than at present.
With the planet currently going through a period of extensive climate change – once again including warmer waters, rising sea levels and shrinking ice sheets – researchers believe there is the potential for such incidents to be replicated.
Through analysing the effects of past underwater landslides, they say future seismic events off the coast of Antarctica might again pose a risk of tsunami waves reaching the shores of South America, New Zealand and South East Asia.
The landslides were discovered in the eastern Ross Sea in 2017 by an international team of scientists during the Italian ODYSSEA expedition.
Scientists revisited the area in 2018 as part of the International Ocean Discovery Program (IODP) Expedition 374 where they collected sediment cores extending hundreds of meters beneath the seafloor.
By analysing those samples, they found microscopic fossils which painted a picture of what the climate would have been like in the region millions of years ago and how it created the weak layers deep under the Ross Sea.
The new study was led by Dr Jenny Gales, Lecturer in Hydrography and Ocean Exploration at the University of Plymouth, and part of IODP Expedition 374.
She said: “Submarine landslides are a major geohazard with the potential to trigger tsunamis that can lead to huge loss of life. The landslides can also destroy infrastructure including subsea cables, meaning future such events would create a wide range of economic and social impacts. Thanks to exceptional preservation of the sediments beneath the seafloor, we have for the first time been able to show what caused these historical landslides in this region of Antarctica and also indicate the impact of such events in the future. 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.”
Professor Rob McKay, Director of the Antarctic Research Centre at Victoria University of Wellington and co-chief scientist of IODP Expedition 374, added: “The main aim of our IODP drilling project in 2018 was to understand the influence that warming climate and oceans have had on melting Antarctica’s ice sheets in the past in order to understand its future response. However, when Dr Gales and her colleagues on board the OGS Explora mapped these huge scarps and landslides the year before, it was quite a revelation to us to see how the past changes in climates we were studying from drilling were directly linked to submarine landslide events of this magnitude. We did not expect to see this, and it is a potential hazard that certainly warrants further investigation.”
Laura De Santis, a researcher at the National Institute of Oceanography and Applied Geophysics in Italy, and also co-chief scientist of IODP Expedition 374, said: “The sediment cores we analysed were obtained as part of IODP, the international seafloor scientific drilling project that has been active in the field of geoscience for over 50 years. The project aims to explore the history of planet Earth, including ocean currents, climate change, marine life and mineral deposits, by studying sediments and rocks beneath the seafloor.”
Jan Sverre Laberg, from The Arctic University of Norway, Tromsø, said: “Giant submarine landslides have occurred both on southern and northern high latitude continental margins, including the Antarctic and Norwegian continental margins. More knowledge on these events in Antarctica will also be relevant for submarine geohazard evaluation offshore Norway.”
Dr Amelia Shevenell, Associate Professor of Geological Oceanography at University of South Florida, College of Marine Science, said: “This study illustrates the importance of scientific ocean drilling and marine geology for understanding both past climate change and identifying regions susceptible to natural hazards to inform infrastructure decisions. Large landslides along the Antarctic margin have the potential to trigger tsunamis, which may result in substantial loss of life far from their origin. Further, national Antarctic programs are investigating the possibility of installing submarine cables to improve communications from Antarctic research bases. Our study, from the slope of the Ross Sea, is located seaward of major national and international research stations, indicating that marine geological and geophysical feasibility studies are essential to the success of these projects and should be completed early in the development process, before countries invest in and depend on this communication infrastructure.”
JOURNAL
Nature Communications
DOI
METHOD OF RESEARCH
Experimental study
SUBJECT OF RESEARCH
Not applicable
ARTICLE TITLE
Climate-controlled submarine landslides on the Antarctic continental margin
ARTICLE PUBLICATION DATE
18-May-2023
Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy
Maybe it is plate tectonics at work? Nothing to do with “climate”.
Part of their training in public relations. In every press release, in every exchange with the media, try really, really hard to mention climate change. This is a must. It will also be a mark that you are a good doobie.
They said in the article that the landslides were caused by earthquakes, and did not make any connection with landslides and the climate that I could see.
Here’s what they said: “However, when Dr Gales and her colleagues on board the OGS Explora mapped these huge scarps and landslides the year before, it was quite a revelation to us to see how the past changes in climates we were studying from drilling were directly linked to submarine landslide events of this magnitude. We did not expect to see this, and it is a potential hazard that certainly warrants further investigation.”
They are saying submarine landslides are directly related to climate but don’t show any connection.
I guess we can chalk it up to religious zealotry.
The connection is their belief that a warmer world would cause these sediment to build up faster.
Dr Jenny Gales has tried really hard, but she is still outside the top ten in the UN official “scary prediction” competition. The judges decided that her submitted scary prediction lacked relevance to people’s lives today because, at the target time of her study, temperatures in Antarctica were up to 3°C warmer than they are today, sea levels were higher and ice sheets much smaller than at present.
3C warmer. That’s funny, considering how cold it is there.
CO2 levels weren’t elevated, therefore it’s impossible for temperatures to have been that warm. /sarc
Or, maybe, “3 degrees less cold”?
That’s a better way to put it.
They are comparing the Miocene-Pliocene a period that lasted about 20 million years with from now until fossil fuels are overtaken by other more efficient energy sources, assuming fossil fuel use has been the main cause of the assumed warming in the past 100 years or so.
That is as absurd as the mixture of time scales and temporal resolution on this graph and many others like it.
I see a “may” in there.
So they don’t really have any evidence.
Somebody needs to teach these scientists the difference between evidence and wishful thinking.
This is true. It does not require climate change. It is a genuine hazard that must be considered appropriately.
Adaptation is the answer. Early warning systems and flood defences.
Both of which need the strongest economy from the cheapest energy.
Coal to the rescue!
No mention of the many volcanoes or the magma chamber….
According to the Guardian we’ve messed up ENSO and we’re all going to die
I see where the ENSO meter has ticked a little bit more towards El Nino.
Well lookee here – these wide-eyed adventurers have stumbled upon soil erosion
Not that they’d know or even want to know even it it bit their backsides.
There-in lies the problem – it will bite all of our backsides – while these hysterical confirmation-seeking clowns are destroying science.
Explain: To set off a tsunami, you need a sudden abrupt ‘volume change’ within the water.
It’s the same if you want to create any sort of ‘wave’ – be it sound, electromagnetic or even gravity.
Classically you may toss a brick into a mill-pond and the resulting ripple(s) are = your tsunami.
e.g Mountains may collapse or as widely foretold, Fuertaventura Island (I think) in the Canaries falls over and floods the entire East Coast.
It will – its a big slab of rock with nothing else to do while a big fugogff subsea vent keeps nudging it
OK, underwater earthquakes set off tsunami, landslides above and below water have happened since forever and maybe yes, underwater avalanches on the leading edge of the continental shelf do look like what an earthquake looks like.
But they’re not – in the subsea landslides there is no sudden/abrupt volume change within the water. ‘Things’ underwater are simply re-arranging themselves = mud moves down a slope and corresponding water moves to fill the void. Mud and water swap places. That’s all.
e.g. Where the brick in the pond was already under the water – moving the brick around will not set off any large surface ripples.
Underwater earthquakes are, can be, the equivalent of throwing a brick into a pond BUT, from underneath.
The underwater quake either creates or disappears a large amount of rock and the water does what’s needed to either move out the way, or to fill the void
Result= tsunami
Say if the pond had a plug-hole and you pulled the plug – or if you pushed an inflated air balloon under the water then popped it. Or went surveying for windmills.
That is the fatal flaw of these clowns, they haven’t learned or don’t know of Archimedes – their whole story, and it is just a story, falls flat on that alone.
reply/edit to laugh at self. – I knew what I meant but didn’t quite get there.
It is that whales, the huge lumps of blubber that live under water, are the equivalents of large lumps of mud.
(Big ‘things’ that are not = 100% water = stuff of different density = what defines the stuff making up these underwater slides)
So, do whales, as they move around under the water like what the mud is doing, set off tsunamis or even noticeable ripples on the surface.
Man-made submarines also.
The only time a whale makes anything resembling a tsunami is when it surfaces.
i.e Some or maybe all part of it leaves the water (volume negative) then falls back into the water (volume positive)
(I don’t tink I should have said that, some clown somewhere might see the elimination of whales as a remedy for sea level rise – this planet is now that dumb)
Do whales set off tsunamis? Of course not. The amount of debris sliding is billions of times greater in mass than are whales. Even a pod of whales.
PS: Stop nipping from the sugar bowl.
I read one time that the Navy was working on a system that used satellites to look disturbances on the oceans surface in order to detect submerged submarines.
Yes, if close enough to the surface, they do.
It’s all a matter of learning to think outside the Boolean box.
It’s not ‘does?’ it’s ‘by how much?’
Peta,you should try telling that to the people of Sumatra in 2004, or the (proto)Norwegians when Storegga let go (ca 6,000 BC). In the case of Sumatra, the seabed dropped about 16 feet and caused a tsunami which caused damage in East Africa and the Storegga slides apparently caused tsunamis which inundated a fair bit of Doggerland.
A big part of the problem is that water is incompressible and has a lot of momentum once it does get moving.
When an undersea landslide occurs, the first thing it does is to push a huge amount of water out of its way. Once that water gets moving, the wave it creates is going to keep moving until it hits something.
Also, once the water is pushed out the way, there is going to be a void in the ocean, where the dirt and water used to be. Water is going to rush in to fill that void, and because of momentum it won’t stop when the void is filled, it will keep moving in the other direction.
Kind of like ringing a bell, the ocean will keep oscillating for a while until the energy dissipates.
The volume of the entire ocean doesn’t change, but the volume of the local area can change dramatically.
When the debris starts to slide, it pushes water ahead of it.
Then when the water tries to return to the area that now doesn’t have enough water, because of all that debris on the ocean floor that is now somewhere else, it creates yet another big wave.
You seem to think that tsunamis are water in motion. They are not, they are waves that move through the water.
Well at least they do admit that the world was warmer, and sea levels higher long before mankind arrived on the planet and messed everything up.
Is this a joke? Santa Klaus “might” also come this Christmas.
I had the same reaction: “Is this a joke?”
” …how the past changes in climates we were studying from drilling were directly linked to submarine landslide events of this magnitude . “
Another Send Money ! claim .
With zero proof , only assertion .
“With zero proof , only assertion .”
Yep. It’s the sad state of climate science.
How do we know that the previous land slides weren’t caused by people drilling into the deposits in order to study them? Retiring minds want to know.
So if these undersea landslides occurred when the Antarctic climate was warmer than now and there was less ice, the ice that is now there is holding back further landslides. Some parts of the ice cap has become anchored to the sea floor and prevent further landslides from occurring.
The Ross Sea is partially or totally covered by ice year round, so that if a new landslide occurred, any tsunami generated would be damped out by ice moving up and down, and friction between pieces of sea ice. The tsunami would be strongest if it occurred during March, when the sea ice on the Ross Sea is at its minimum.
Mark Twain said it all: “There is something fascinating about science. One gets such wholesale returns of conjecture out of such a trifling investment of fact.”
Only theories compliant with alarmists’ beliefs will be considered possible!
“generated tsunami waves“, how specious of them.
Other tsunami sites identify landslides involving many cubic miles of landslide to generate significant tsunami.