A new study reveals that the largest active underwater volcanic eruption recorded in 2018 gave birth to a giant “baby”: an underwater volcano on the scale of a skyscraper.
Scientists have discovered a 2,690-foot (820-meter) volcano in the western Indian Ocean beyond Madagascar after a series of incredible earthquakes near a normally calm area. After collecting geological data, the team realized that the new underwater volcano is 1.5 times the size of the New York volcano, including data from the 2019 Underwater Study of the region. A World Trade Center. In addition, this new “baby” comes from the deep reservoir of volcanic magma known to scientists.
“The source of the magma, the reservoir is very deep,” said Natalia Foyer, a 55-kilometer underground geologist at the University of Paris. “This is the first time in the volcano that a reservoir so deep can be seen at the base of the lithosphere,” said the Earth’s exosphere, which includes the crust and the crust.
Between May 2018 and May 2021, the small island of Mayotte and the French territory between Madagascar and Mozambique were shaken by more than 11,000 earthquakes detected. It was a strong earthquake with a force of 5.9 points, but even that Strange seething earthquakesOr very low frequency earthquakes that form deep in the earth; It cannot be felt on the surface, but it has been felt by seismologists all over the world. These low frequency earthquakes are associated with volcanic activity.
The epicenter has, however, been reported below the bottom of the Pacific Ocean; no tsunami alert was issued for the epicenter.
In July 2018, scientists realized that Mayotte was moving about 7.8 inches (20 cm) east per year, according to GPS data. At the time, there were only three or four GPS stations on the island, so scientists installed global navigation satellite systems and seismic maps to learn more about the geological changes at the bottom of the sea. island ocean. The results are extraordinary: between February and May 2019, researchers found that land and sea seismic measurements recorded 17,000 cases.
In May 2019, Willett and his colleagues had the opportunity to sail aboard the research vessel Marion Dufresne. The team knew there was a rocky event east of Mayotte, but they didn’t know if the magma was buried deep or if it had seeped into the ocean.
“We expected to see something, but it wasn’t clear,” Foyer said.
In 2019 MailHe writes: “We have developed a protocol for analyzing seismic signals recorded by OPS. [ocean-bottom seismometers]. Working 24 hours a day, in teams, the teams were able to accurately detect nearly 800 earthquakes (between 3.5 and 4.9) in two weeks. ”
Their efforts paid off: “We found that most of these earthquakes were very close to the island (10 km). [6 miles] From the east coast of the island), but it was deep (20 to 50 km [12 to 31 miles] Deep), ”Foyers wrote.
The ship’s multibeam echo probe transmits sound waves to map ocean waves and the water column, then finds a “very large” one 31 miles east of Mayotte, Wolet said. It was an underwater volcano, the pyramid-shaped building measuring about 5 cubic kilometers. This volcano is completely new; This was not the case in 2014, according to a previous survey by the Marine, Hydrography and Oceanography Service.
According to the 2014 census, the area is “almost flat – approximately 3,300 square meters [10,827 feet] Below sea level.
These volcanic eruptions are 30 to 1000 times larger than other documented deep water eruptions. This is three times the size of the Howrah 2012 eruption in New Zealand and 2.5 times the size of the 2014 Bournemouth eruption in Iceland, the largest eruption in Iceland in 200 years.
Seems Tectonic plates This movement caused the growth of lava in the austenosphere, the molten layer above the shell below the hard lithosphere. This magma flows into geological dams, which could explain the earthquake and the mass eruption that followed.
Also, this eruption is not visible for the first time near Mayotte. “Large pyroclastic flows and cones on the upper slope and on the myocyte shore suggest this has happened in the past,” the researchers wrote in the study.
The team is also monitoring the area for seismic and volcanic activity. “It’s always exploding,” Foyer said. The last source of lava in the ocean dates back to January 2021. “
The study was published in an online journal on August 26. Natural Earth Sciences.
First published in Live Science.