The largest underwater eruption caused a massive volcano to rise up from the seafloor, leading researchers to investigate.
On May 10, 2018, researchers recorded a seismic event that caused a volcanic island to emerge from the seafloor between Madagascar and East Africa. Within a few days of the island emerging, researchers recorded a 5.8 earthquake that was traced back down to volcanic activity underwater. In February 2019, teams of researchers mapped 3,320 square miles of the seafloor with sonar in an effort to gain more knowledge of the event.
The researchers found that more than 17,000 seismic events occurred between February and May 2019 at a depth of 30 miles beneath the seafloor. The researchers dubbed the discovery of these seismic events as "highly unusual". From these observations, the researchers were able to construct a model of how the volcanic island came to be and found that the island started with magma below the molten mantle.
The researchers explained, "The earthquakes have been much deeper than usual in a volcanic context and occur below the boundary between the crust and the mantle. They point to the existence of very deep reservoirs and drainage systems spread throughout the lithosphere, which had never before been clearly observed in volcanology."
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