underwater eruption off the French island of Mayotte gave birth to a new colossal seamount | Smart News

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The volcano (not visible in this image) emerged near the island of Mayotte (photo), located between East Africa and Magagascar.
International Space Station via Wikicommons in Public Domain

In 2018, seismometers around the world detected mysterious rumblings emanating from a generally calm area of ​​the Indian Ocean between the Comoros and Madagascar. At the time, researchers were amazed to find an underwater volcano 2,690 feet tall, about 1.5 times the height of One World Trade Center in New York City.

The volcano formed after the largest underwater eruption ever detected and now scientists suspect the volcano is drawing its lava from the deepest reservoir of volcanic magma known to researchers, reports Laura Geggel for Live Science. The study was published in August in the journal Geosciences of nature.

Scientists first noticed volcanic activity about 50 kilometers east of the French island of Mayotte in 2018 when seismic hums, or low-frequency earthquakes, were detected by seismometers all over the place. the world. However, the huge underwater volcano shocked scientists as only two seismic events had been recorded near Mayotte since 1972. Before that, a 4000-year-old layer of pumice stone in a nearby lagoon was the only further evidence of it. ‘a rash never found, by Live Science.

After the researchers noticed that the island was moving eastward about 7.8 inches per year, they installed ocean floor seismometers and GPS systems to track the island’s fascinating geological activity, through Live Science.

To understand the origin of the tremors that began in 2018, the main author of the study, Nathalie Feuillet, marine geoscientist at the National Center for Scientific Research, and her team embarked on a mission called MAYOBS1 aboard the ship. French research. Marion dufrense in 2019.

“We expected to see something, but it was not certain,” says Feuillet. Live Science.

The team kept an eye on the area near the island of Mayotte, covering more than 8,500 square kilometers of seabed, with seismometers and sonar located about 3,500 meters below sea level, Daniel reports. Lingenhöhl for American scientist. The team knew there was a magma event to the east of the island, but they weren’t sure whether the magma had remained under the crust or if it had erupted on the seabed, for example. Live Science.

An underwater eruption off the French island of Mayotte has given rise to a colossal new seamount

Scientists first noticed volcanic activity off the island of Mayotte in 2018 when seismic buzzes or low-frequency earthquakes were detected by seismometers around the world. The top image shows the seismic swarms detected in the east of the island of Mayotte in October 2019. The bottom image shows the new lava flows observed.

IPGP, BRGM, IFREMER, CNRS and University of Paris

Between February and May 2019, the team’s equipment recorded 17,000 vibrations from 20 to 50 kilometers below the sea crust. Next, the ship’s echosounder, a system that maps the seabed using sound waves, detected an underwater volcano measuring about 1.2 cubic miles, Live Science reports.

Using all the data combined, the research team closely analyzed the seismic waves collected by the equipment and were able to reconstruct the formation of the underwater volcano, by American scientist. Before the volcano emerged at 8,465 feet below sea level, the area was nearly flat. In addition, the submarine massif did not appear in a previous geological study carried out by the Hydrographic and Oceanographic Service of the Navy in France in 2014.

“For me, the claim ‘the largest active underwater eruption ever documented’ misses the most important point,” said William W. Sager, a geophysical expert not involved in the research. American scientist. “Few underwater eruptions have been documented as they are typically hidden under miles of opaque ocean water. Little is known about the formation of seamounts, but the authors captured it as it occurred. More importantly, they were able to show where the magma came from and how it came to the surface.

The colossal submarine volcano formed from a large magma chamber just below the earth’s crust. The movement of the tectonic plates tore the rock in the crust, and the magma rose up and formed geological dykes, which are rocks that fill larger holes and cut through the surrounding rock layers, reports American scientist. This process created the seismic activity, and as soon as the magma hit the seabed, it built the volcano as its lava reservoir emptied. Scientists are still monitoring the area for more quakes and volcanic activity. The most recent evidence of seabed magma was recorded in January 2021, Feuillet said Live Science.


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