A new study reveals that the largest active underwater volcanic eruption recorded in 2018 gave birth to a giant “baby”: an underwater volcano on a skyscraper scale.
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 quiet area. After collecting geological data, the team realized that the new underwater volcano is 1.5 times larger than the New York volcano, including data from the 2019 underwater survey of the area. 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 34-mile (55-kilometer) underground geologist at the University of Paris. “This is the first time in the volcano that such a deep reservoir can be seen at the base of the lithosphere,” said the Earth’s exosphere, which includes the crust and crust.
Related: Photos: A fiery volcano erupts from the Klavia volcano in Hawaii
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 detected earthquakes. It was a strong earthquake with a strength of 5.9 points, but even that Strange bubbling earthquakesOr very low frequency earthquakes that form deep in the earth; This cannot be felt on the surface, but it has been felt by seismologists around the world. These low frequency earthquakes are associated with volcanic activity.
The epicenter was reported below the Pacific Ocean floor, however; no tsunami alert was issued for the epicenter.
In July 2018, scientists realized that the Mayotte was moving about 7.8 inches (20 cm) east a 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 geological changes on the island’s ocean floor. The results are extraordinary: between February and May 2019, researchers found that land and sea seismic measurements recorded 17,000 cases.
Sea voyage
In May 2019, Willett and his colleagues had the opportunity to sail aboard the research ship Marion Dufresne. The team knew there was a rocky event east of Mayotte, but they did not know if the magma was deep in the surface or leaked into the ocean.
“We were expecting to see something, but it wasn’t clear,” Foyer said.
In 2019 MailHe wrote: “We have developed a protocol for analyzing seismic signals recorded by the OPS. [ocean-bottom seismometers]. Working 24 hours a day, in shifts, 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 multi-beam echo probe transmits sound waves to map the ocean wave and water column, and then finds one “very large” 31 miles east of Mayotte, Wolet said. It was an underwater volcano, the pyramid-shaped building measuring about 1.2 cubic miles (5 cubic kilometers). This volcano is completely new; This is not the case in 2014, according to a previous survey by the French Navy, Hydrographic and Oceanographic Service.
According to the 2014 census, the area is “almost flat – about 3,300 square meters [10,827 feet] Below sea level.
These volcanic eruptions are 30 to 1000 times larger than other documented deep-sea eruptions. It is three times the size of the 2012 Howrah 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 lava to grow in the austenosphere, the molten layer on top of the shell below the hard lithosphere. This magma flows into geological dams, which could explain the earthquake and subsequent mass eruption.
Also, this eruption is not visible for the first time near Mayotte. “Large pyroclastic flows and cones on the upper slope and on the shore of the myocyte suggest that 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 still explodes,” Foyer said. The last source of lava in the ocean was in January 2021. “
The study was published in an online journal on August 26 Natural Earth Science.
First published in Live Science.