The strongest ever seismic activity recorded in Antarctica saw a swarm of 85,000 earthquakes triggered in a span of just four months back in 2020. It was caused by a volcano, that had long been dormant, finally waking up.
The swarm of earthquakes kicked off in August of 2020 and waned in around 4 months by November the same year. The massive quake swarm was likely the result of a “finger” of hot magma pushing into Earth’s crust, new research published in the journal Communications Earth & Environment suggests.
Such “intrusions” have been observed in other regions on the planet but the August-November 2020 activity was the first recorded in Antarctica, co-author of the study Simone Cesca GFZ German Research Centre for Geosciences in Potsdam was quoted by Live Science.
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The phenomenon that occurred in Antarctica usually occurs over extremely long durations of time compared to the life span of humans, which makes the observation a “lucky” one, says the scientist.
The place where the earthquake swarm was triggered is known as Orca Seamount, which is an inactive volcano that is 900 metres (2,950 feet) above the floor of the sea in the Bransfield Strait which lies between the north-western tip of the continent and the South Shetland Islands. It was at one of the research stations on King George Island in the South Shetland Islands where scientists first noted the small tremors.
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One tectonic plate going under another one has resulted in a network of fault zones in the region which has created rifts in places and stretched the crust in others, a study published in the journal Polar Science in 2018 found out.
Among the series of earthquakes that hit the region, the two strongest ones were of 5.9 magnitued (in October 2020) and 6.0 magnitude (in November 20020). The activity subsided after the large November earthquake. The scientist added that an underwater volcanic eruption, if any happened, was likely at this time. However, direct evidence hasn’t been found till now that could point to a massive volcanic eruption undersea.
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