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Scientists Just Observed The World’s Largest Underwater Volcanic Eruption

Last year, scientists were stunned when an unexplained sonic phenomenon was recorded deep under the Indian Ocean. A twenty-minute pulse of extremely low frequency waves were recorded coming from the seafloor near the French-controlled island chain of Mayotte off the coast of Madagascar. Whatever the mysterious disturbance was, it was huge.

Petite-Terre, Mayotte.

Petite-Terre, Mayotte.

A few months ago, scientists discovered that Mayotte is sinking and migrating eastward at a terrifyingly fast rate and began to suspect that a huge pocket of magma was flowing to the Earth’s surface somewhere off the coast. It turns out those suspicions were current, because a team of French scientists has just announced the discovery of the world’s largest underwater volcanic eruption. According to the researchers, this eruption is the most likely cause cause of the 2018 acoustic anomaly.

The French Ministry of the Interior issued a press release this week describing the discovery of a massive magma plume rising from the volcano. “We have never seen anything like this,” says Nathalie Feuillet, leader of the expedition to study the site. Data gathered from seismometers placed 3.5 kilometers (2 miles) beneath the sea and recent multibeam sonar sweeps indicate as much as 5 cubic kilometers (1.2 cubic miles) of magma may have erupted onto the sea floor in recent months. A new mountain rising 800 meters high (.5 miles) and stretching 5 kilometers across (3 miles) has been detected by sonar – a mountain which was not there six months ago.

Sulfur gas bubbles rising from a seafloor volcano.

Sulfur gas bubbles rising from a seafloor volcano.

Local fisherman near Mayotte and Madagascar have reported entire schools of dead fish reeking of sulfur or other chemicals, discoveries which also indicate a massive volcanic eruption somewhere deep under the ocean. Given that volcanic rock has been dredged up from the sea floor, it’s pretty clear that some type of serious magma flow is happening on the bottom of the Indian Ocean, activity which could have dire consequences for Mayotte and its residents. The island has already moved ten centimeters to the east and has sunk by 13 centimeters in just a year. If this volcanic activity continues, there’s the distinct possibility the island could fall further into the sea in our lifetime; of course, it could also be that an entirely new landmass could rise off the coast of Mayotte.

Magma ejecting from a submarine volcano.

Magma ejecting from a submarine volcano.

The face of the Earth has been relatively unchanged throughout our lifetimes. While climate change, pollution, and human population growth have altered the face of our planet somewhat, we haven’t lost or gained any major land masses to volcanic or seismic forces in quite some time. Where will the next Pompeii occur? Could Mayotte be next?