Strange seismic waves were captured around the globe on November 11th. Seismologists are now trying to understand why

Seismic sensors first detected the event near an island located between Madagascar and Africa. Then, warning signals sounded as far as Chile, New Zealand and Canada

Hawaii, almost exactly on the other side of the planet, also picked up "the event".

Nobody knows what he was. 19659004] Meteorite? Underwater volcano? Nuclear test?

"I do not think I have seen anything like it," said Göran Ekström, a seismologist at the University of Colombia, quoted by National Geographic. "It does not mean that in the end, their cause is exotic."

At the center of the mystery lies the small island of Mayotte, located halfway between Africa and Madagascar. It has been subjected to a swarm of earthquakes since May. Most were minor, but the most important – on May 8 – was the largest in the history of the island, reaching a peak magnitude of 5.8

But the swarm of tremors was declining before the mysterious ring was detected earlier this month.

Ekström, a specialist in unusual earthquakes, points out that the November 11 event was strange. It was as if the planet was ringing like a bell, maintaining a low frequency single frequency throughout its spread.

Earthquakes, by their very nature, usually record very short "cracks". As tensions in the Earth's crust subside rapidly, clearly identifiable seismic waves radiate from where the landslide occurs.

The first signal is called the primary wave: the high frequency compression waves that radiate in clusters.

a secondary wave: these high frequency waves tend to "move" a little more.

Next come surface waves: these slow, deep snores tend to linger and can circle the Earth several times.

The event is notable in that no primary or secondary wave has been detected.

The recording was only the deep surface wave and resonant. And that was not "scolded" as would the surface wave of an earthquake. Instead, he maintained a much cleaner frequency – almost musical.

According to National Geographic, French geological authorities suspect a new volcano to develop off the coast of Mayotte. Although the island was created by volcanic activity, it has been dormant for more than 4000 years.

The French believe that this strange ringing may have been generated by a movement of magma located about 50 km from the coast and under deep water. This is corroborated by the GPS sensors that detect that Mayotte has moved about 5 cm to the southeast in less than five months.

But it is a poorly mapped region.

Ekström thinks that the unusually pure signal could have been caused by the slippage of magma inside a chamber or by the forced pbadage through a hole in the subterranean rocks.

But it is not certain