Past Climate Change Caused Massive Underwater Landslides in Antarctica – Watts Up With That?
UNIVERSITY OF PLYMOUTH
Scientists have discovered the cause of giant underwater landslides in Antarctica that they believe may have created tsunamis that spread across the Southern Ocean.
An international team of researchers has discovered layers of weak, fossilized and biologically rich sediment hundreds of meters below the seafloor.
They are formed beneath large areas of underwater landslides, many of which cut more than 100 meters into the seafloor.
written in natural communicationThese weak layers – made up of historic biological material – make the area vulnerable to destruction in the face of earthquakes and other seismic activity, scientists say.
They also note that the layers were formed at a time when Antarctica’s temperatures were up to 3°C warmer than today, when sea levels were higher and ice sheets were much smaller than they are today.
With the planet currently undergoing a period of extensive climate change – again including warmer waters, rising sea levels and shrinking ice sheets – researchers believe it is likely that these events will occur. The same attempt will repeat.
By analyzing the impact of past underwater landslides, they say future seismic events off the coast of Antarctica could once again pose a tsunami risk to the coast of South America. , New Zealand and Southeast Asia.
The landslides were discovered east of the Ross Sea in 2017 by an international team of scientists during the Italian ODYSSEA expedition.
The scientists revisited the area in 2018 as part of the International Ocean Discovery Program’s (IODP) Expedition 374, where they collected sediment cores extending hundreds of meters below the seafloor.
By analyzing those samples, they found microscopic fossils that paint a picture of what the climate would have been like in the region millions of years ago and how it created weak layers deep under the Ross Sea.
The new research was led by Dr Jenny Gales, Lecturer in Oceanography and Exploration at the University of Plymouth, and part of IODP Expedition 374.
She speaks: “Undersea landslides are a major geological hazard with the potential to trigger a tsunami that can lead to great loss of life. Landslides can also destroy infrastructure including underground cables, meaning that such events in the future will create many economic and social impacts. Thanks to With special conservation of seafloor sediments, we are able to show for the first time what caused these historic landslides in this Antarctic region and also show the impact of such events in the future. future. Our findings highlight the urgent need to improve our understanding of how global climate change may affect the stability of these regions and the likelihood of future tsunamis. future.”
Professor Rob McKay, Director of the Center for Antarctic Studies at Victoria University of Wellington and co-lead scientist of IODP Expedition 374, added: “The main aim of our IODP drilling project in 2018 was to understand the effects of climate and ocean warming on past Antarctic ice melting in order to understand its response in the future. . However, when Dr Gales and her colleagues aboard the OGS Explora mapped these massive cliffs and landslides last year, we made the rather exciting discovery of seeing changes in the landscape. The climate past that we’re studying from drilling is directly related to undersea landslide events of this magnitude. We didn’t expect to see this, and it’s a potential danger that definitely needs further investigation.”
Laura De Santis, a researcher at the National Institute of Oceanography and Applied Geophysics in Italy, and co-chief scientist of IODP Expedition 374, said: “The sediment cores we analyzed were obtained from IODP, the international seabed science drilling project that has been active in the geosciences field for more than 50 years. The project aims to explore the history of planet Earth, including ocean currents, climate change, marine life and mineral deposits, by studying the sediments and rocks of the seafloor.”
Jan Sverre Laberg, from Norway’s Arctic University, Tromsø, said: “Massive underground landslides have occurred on both the southern and northern high-latitude continental margins, including the continental margins of Antarctica and Norway. Further knowledge of these Antarctic events would also be relevant for undersea geological risk assessment off the coast of Norway.”
Amelia Shevenell, Associate Professor of Oceanography at the University of South Florida, College of Marine Sciences, said: “This study illustrates the importance of scientific ocean drilling and marine geology to understand both past climate change and to identify disaster-prone areas to inform decisions about climate change.” the infrastructure. Large landslides along the edge of Antarctica have the potential to trigger tsunamis, which can lead to significant loss of life far from their origin. Furthermore, the National Antarctic Program is investigating the possibility of installing submarine cables to improve communications from research facilities in Antarctica. Our study, from the slope of the Ross Sea, which lies to the sea of major national and international research stations, indicates that feasibility studies of marine geology and geophysics are needed for the success of these projects and should be completed early in the development process, before the countries that invest in and depend on this communication infrastructure.”
MAGAZINE
natural communication
DOI
RESEARCH METHODS
Experimental study
RESEARCH SUBJECTS
do not apply
ARTICLE TITLE
Climate-controlled underground landslides at the edge of the Antarctic continent
ARTICLE PUBLICATION DATE
May 18-2023
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