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A violent supervolcano seems to be coming back to life

A supervolcano has had its alert level raised following 700 earthquakes nearby.

Taupō Volcano, which is a supervolcano beneath New Zealand’s largest lake, Lake Taupō, saw its Volcanic Alert Level (VAL) drop from 0 to 1 on September 20. Level 1 indicates minor volcanic unrest, according to GeoNeta geohazard agency in New Zealand.

Lake Taupō sits within the giant caldera of a supervolcano on New Zealand’s North Island, about six miles above the magma chamber. The volcano has erupted 25 times in the past 12,000 years, most recently in AD 232, resulting in the largest and most violent eruption on Earth in the past 5,000 years.

Supervolcanoes, which also include Yellowstone, Long Valley in eastern California and Toba in Indonesia, are volcanoes that erupt with a magnitude of 8 or greater on the Volcano Explosivity Index, meaning that deposits of the eruption extend over 240 cubic miles.

According to GeoNet, more than 700 earthquakes have been recorded under Lake Taupō in 2022, with an increase in the frequency of these earthquakes since May, at depths between 2.5 and 8 miles below the lake.

This is the first time that GeoNet has increased Taupō Volcano’s VAL to 1, however, there have been 17 previous episodes of similar volcanic unrest over the past 150 years, some of which were more severe than currently observed. The VAL scale ranges from 0, with no volcanic agitation, to 8, representing a mega-colossal volcanic eruption.

“None of these episodes, nor the many other episodes believed to have occurred over the past 1,800 years before written records were kept, ended in an eruption,” GeoNet said in a statement. “The probability of an eruption at Taupō remains very low over the course of a year.”

The earthquakes near Lake Taupō were caused by volcanic unrest, according to GeoNet, which is when magma or hot water and steam heated by magma force their way through the ground, resulting in earthquakes and ground movements.

Research published in the New Zealand Journal of Geology and Geophysics in February found that the ground under Lake Taupo had shifted. According to the document, the ground at the south end of the lake sank 5.5 inches, while at the northeast section, with the most active vents, the ground rose about 6.3 inches.

According to GeoNet, volcanic unrest at Taupō could continue for months without a real eruption. However, it could cause landslides resulting from earthquakes, mud lahars (a violent type of mudslide or debris flow), and ground subsidence.

Another New Zealand volcano made headlines in 2019 when White Island or Whakaari suddenly erupted as a group of tourists were hiking on the island, killing 22 people and seriously injuring 25 others.

“Taupō will most likely erupt at some point over the next few thousand years – and so it is important that we monitor and understand these troubled times so that we can quickly identify any signs that may indicate an upcoming eruption,” said Finn, a seismologist from Victoria University of Wellington. Illsley-Kemp told the New Zealand Herald in 2021.

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