A scientific study revealed 368 glacial earthquakes hidden beneath the Antarctic layersa sign of the intense life that flows in this white giant, says a work published in Open ESS archive.
An expert with the latest technology and many days in front of surveillance screens Australia managed to identify what no one had seen before: invisible seismic movements that reveal the pulse of the Thwaites and Pine Island glaciers.
The study, which is still awaiting peer review, suggests that Antarctica’s heart is constantly beating and creaking, which has direct effects.
These earthquakes can foreshadow the release of large blocks of ice and sudden changes in the glacial shelf.one of the fundamentals of marine health.
The work was led by Thanh-Son Phạm des Australian National University Geosciences Research School.
The idea of searchingGlacial earthquakes“ in Antarctica arose from a question: Why are many events recorded in Greenland and almost none in the Southern Hemisphere?
So far, only a few seismic changes have been recorded, always in remote glaciers in East Antarctica.
The data breach led to questions about whether the seismic phenomenon in Antarctica was unusual or whether previous technology was simply unable to detect it.
This is how the goal was defined: to use a combination of sensors and algorithms to record signals from earthquakes caused by large blocks of ice breaking off from glaciers.
The focus was on two colossi: Thwaites And Pine Islandchosen because of their size and their importance to the balance of the ocean.
The aim was to find out whether these giants cause seismic movements like those that have already been studied in the northern hemisphere.
The main method of the study was crucial. A network of seismic stations stationed over the western Antarctic region between 2010 and 2023.
The stations collected signals for thousands of hours, tracking Rayleigh waves that propagate through the Earth’s crust during seismic events.
To extract the glacial earthquakes, an algorithm was used that filtered the signals from the glacial earthquakes “Coherence of surface waves”.
Scientists then examined each case to distinguish regular tectonic movements from those created by ice.
The main result of the work is a catalog of 368 seismic events that were systematically detected using regional surface waves. A comparable list has never been created in Antarctica.
65% of detected earthquakes occurred nearby Thwaites Glacier. The rest on Pine Island.
Satellite images taken before and after the events confirmed that they were associated with large, newly separated blocks, recognizable by their temperature and distinctive texture.
The analysis also found that the vast majority of tremors originated in the region “Rotation or overturning of recently separated icebergs” on the Thwaites Front, with forces aligned in the direction of glacial flow. This phenomenon was observed twenty years ago in Greenland.
This is what the author explained His research showed that glacial earthquakes, different from those in Greenland, occur frequently in Antarctica..
The nature of the signal, which is much slower and localized, would explain why it had not been seen before, even with sophisticated equipment.
There is still no clear explanation for some of Pine Island’s earthquakes. Although they were located near the floating front, it was not possible to assign them to specific landslides. This mystery remains open to new studies.
The measured magnitudes were between 2 and 3 on the surface size scale. The pattern of events did not show seasonality, but rather coincided with periods when the ice tongue at Thwaites accelerated sharply.
The scientist recommended preservation and improvement seismic network in Antarctica so as not to lose details about ice changes that directly affect the global ocean.
Detecting these movements can help predict unexpected shifts and breaks.
Among the caveats, it was noted that the parameters chosen in the algorithms were based on experience, so “the completeness of the identified sample cannot be guaranteed.” Nevertheless, the 368 events reveal a new world beneath the surface.
The future of Antarctic monitoring could include artificial intelligence and more automated sensors to capture even more subtle and frequent signals. It is not yet known how much ice is released by these earthquakes and to what extent this contributes to sea rise.
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