The birth of a submarine volcano in the Indian Ocean has caused mysterious seismic ripples

The birth of a submarine volcano in the Indian Ocean would have caused a succession of mysterious earthquakes around the world throughout the past year.

Seismic sensors detected short bursts of seismic activity up to a distance of 10,000 km from the location of the "submarine volcano" near the French island of Mayotte.

The birth of the mountain caused a series of earthquakes that were felt daily by islanders and further by experts using seismographs.

Researchers from France's National Center for Scientific Research (CNRS) wanted to clarify the origin of the small earthquakes that rocked the island, located between Africa and Madagascar.

According to the French Bureau of Geological and Mining Research, the team discovered a new "submarine volcano" located 50 km away.

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In the photo, reflected sonar waves on the seabed near the French island of Mayotte reveal the outlines of a 800-meter (red) volcano and a gas-rich ascending plume. The French office says that the birth of a submarine volcano was observed for the first time

The office reported that the birth of the volcano, located 3,500 meters under water, was observed for the first time.

Sitting from the bottom of the ocean, the summit has an estimated height of 2,600 feet (800 meters) and a width of three or four miles.

They also claim that its plume of volcanic fluids emanating from its highest point, or crater, extends for 2 km.

In the previous cards, there was nothing there. & # 39; This thing was built from scratch in 6 months! & # 39; said Marc Chaussidon, director of the Institute of Geophysics of Paris (IPGP).

The small population (500,000 inhabitants) of Mayotte knew for months that something was happening.

Since the middle of last year, they have felt almost daily small earthquakes, said Laure Fallou, sociologist at the Euro-Mediterranean Seismological Center of Bruyères-le-Chatel, France.

Mayotte has a seismometer, but the triangulation of the source of the rumblings would require several instruments, the closest being in Madagascar and Kenya.

A scientific campaign only began in February, when the team placed six seismometers at the bottom of the ocean, near the activity.

Unexpected seismic activity was felt on the French island of Mayotte, wedged between Madagascar and Africa, in the Indian Ocean and recorded by seismograms located 10,000 miles away since 2018.

The seabed map, made by the ship's multibeam sonar, indicates that no less than 5 cubic kilometers of magma broke into the bottom of the sea.

The sonar also detected plumes of water rich in bubbles rising from the center and flanks of the volcano.

In the previous cards, there was nothing there. & # 39; This thing was built from scratch in 6 months! & # 39; Mr. Chaussidon said.

Scientists are currently processing data acquired in recent months and are attempting to evaluate seismic, volcanic and tsunami effects.

The crew also dredged rocks on the flanks of the newborn volcano, which "burst as they brought them on board"

The Paris Institute of Geophysics (IPGP), said Nathalie Feuillet – a sign of high-pressure gas trapped inside black volcanic material.

The study should be published in the journal Nature at an indeterminate date.

How are earthquakes measured?

Earthquakes are detected by following the size or magnitude and intensity of the shock waves they produce, called seismic waves.

The magnitude of an earthquake differs from its intensity.

The magnitude of an earthquake refers to the measure of energy released at the origin of the earthquake.

The magnitude is calculated on the basis of measurements made on seismographs.

The intensity of an earthquake refers to the force of the tremor produced by the sensation.

A magnitude 5.3 earthquake hit the Channel Islands off the south coast of California at 10:30 am Thursday.

According to the United States Geological Survey, "Intensity is determined from the effects on people, human structures and the natural environment".

Earthquakes occur below the surface of the Earth in a region called the hypocentre.

During an earthquake, part of a seismograph remains motionless and a part moves with the surface of the Earth.

The earthquake is then measured by the difference in position of the fixed and moving parts of the seismograph.