On Sunday November 11, around 9.30 am, a series of strange seismic waves rolled around the world. The ripples, that originated 15 miles off the shores of a tiny island Mayotte in the Indian Ocean, lasted for 20 minutes.
Mayotte is located between Madagascar and Africa. After originating in the island, the seismic pulses rolled across Africa, in Zambia, Kenya, and Ethiopia. It then crossed the Atlantic and were recorded in Chile, New Zealand, Canada, and even Hawaii nearly 11,000 miles away, reported the National Geographic.
Strangely, no human being felt or noticed it. But machines did.
One earthquake enthusiast with the handle @matarikipax picked up the unusual activity.
“This is a most odd and unusual seismic signal,” the handle tweeted, later adding “The signal can be seen all around the world.”
This is a most odd and unusual seismic signal.
Recorded at Kilima Mbogo, Kenya ...#earthquakehttps://t.co/GIHQWSXShd pic.twitter.com/FTSpNVTJ9B— ******* Pax (@matarikipax) November 11, 2018
The post has generated the tremendous interest of seismologists on Twitter, starting a global discussion as to what caused the caused the waves.
The seismic activity was quite similar to those seen after massive earthquakes. In a typical earthquake, the fastest travelling signal known as primary or P waves reach seismographs first. This is a reading of strong repeated tremors. This is followed by S or Secondary waves, a long side-to-side motions. And finally, the 'slow waves', which are like a prolonged rumble – similar to the waves triggered at Mayotte.
But interestingly no such earthquake took place at that time in Mayote and anywhere else it was recorded.
So what's the cause behind it?
Several theories are now floating around it. Was it a meteorite activity? Some ancient underwater monster? A submarine volcano? Nuclear test?
"I don't think I've seen anything like it," Colombia University seismologist Göran Ekström tells National Geographic. "It doesn't mean that, in the end, the cause of them is that exotic."
This is a most odd and unusual seismic signal.
Recorded at Kilima Mbogo, Kenya ...#earthquakehttps://t.co/GIHQWSXShd pic.twitter.com/FTSpNVTJ9B— ******* Pax (@matarikipax) November 11, 2018
Researchers are now predicting it could be a signal of magma beneath the volcanic island shifting offshore or underwater quake. But the jury is still out on what caused these ripples.
