Seismic sensors first took an event near the island between Madagascar and Africa. Then the alarm bells started calling as far as Chile, New Zealand and Canada.
Hawaii, located almost on the other side of the planet, also hosted an "event".
No one knows who it was.
Meteorite? Underwater Volcano? Nuclear testing?
"I do not think I've seen anything like that," says Goran Extreme, seismologist at Columbia University of National Geographic news. "It does not mean that ultimately their cause is so exotic."
The center of Mystery is the small island of Mayotte, located approximately halfway between Africa and Madzahar. Since May it has been subjected to earthquakes. Most of them are small, but most – on May 8 – was the largest island in history, exceeding 5.8.
But the earthquake in the west was reduced before the detection of a mysterious bell began at the beginning of this month.
Extreme, who specializes in unusual earthquakes, points a lot to the 11th of November, which was strange. It was as if the planet was calling as a bell, keeping the low frequency monotonous as it spread.
Earthquakes usually occur in nature as short, sharp "cracks". As suddenly released tensions in the Earth's crust, explicit seismic wave pulses radiate out of the place where slipping occurs.
The first signal is called the primary wave: high-frequency compression waves that emit bunches.
Then comes the secondary wave: these high-frequency waves usually "overdo" a little more.
Only then comes the surface of the surface: these slow, deep rumbles tend to be delayed and can crop the Earth several times.
The November 11 event is significant because no primary or secondary waves were discovered.
Everything that was registered was a deep, resonant surface wave. And it was not "rumble" because the earthquake surface wave tends. Instead, it retained a much cleaner – almost musical – frequency.
French Geological Survey National Geographic reports suspect that the new volcano may develop on the coast of Mayotte. While the islands were volcanic, it has been slowed down for more than 4,000 years.
The French people believe that strange bells can be caused by magma moving about 50 km from the coast and below the deep water. It is supported by GPS sensors that reveal that Mayotte has moved about 5 cm south-east for less than five months.
But this is a badly mapped region. Only what lies beneath the ocean can only be guessed.
Extreme believes that an unusually pure signal could be caused by the magma that precipitates inside the chamber or it is forced through the space underwater stones.
But he is not sure.