Been meaning to post this for a week or so.
Unusual seismic waves traveled around the world on Nov. 11 and scientists say they haven't seen anything like it before.
The rumbling originated just offshore of Mayotte, an island between the southeast coast of Africa and Madagascar, before shaking through Africa. Locations in Zambia, Kenya and Ethiopia recorded the rumbling. Even further away, places in Chile, New Zealand, Canada and Hawaii picked up the rumblings.
What the French Geological Survey (BRGM) called the "atypical very low-frequency signal" was a repeating wave that would register about every 17 seconds and lasted some 20 minutes total. Strangely, nobody felt it.
"I don't think I've seen anything like it," Columbia University seismologist Göran Ekström told National Geographic. "It doesn't mean that, in the end, the cause of them is that exotic."
A typical earthquake will release the extent of its energy in one burst, containing several different types of waves.
First are P-waves, otherwise known as compressional waves, according to the U.S. Geological Survey. They shake the ground back and forth in the motion the wave moves. They typically are felt in small jolts or light shaking, though sometimes, they're not felt at all.
Next come S-waves, or shear waves. Shear waves shake the ground in the direction perpendicular to the movement of the wave. These are felt in larger jolts or stronger shaking.
The third type of wave is surface waves, which are trapped near the Earth's surface. A rolling motion can be felt with surface waves.
Surface waves are the most comparable type of wave to that of the one recorded Nov. 11. In a large earthquake, surface waves can buzz around the globe multiple times.
But there was no earthquake large enough to fuel a wave like the one recorded across such a widespread area, and no P- or S-waves were recorded. Even more bizarre, the waves that stemmed from Mayotte were too clean-cut and uniform compared to a normal earthquake, which has waves of differing frequencies.
Scientists suggest that the recent strange waves are linked to an earthquake swarm that's been taking place off the Mayotte coast for months. Several hundred seismic events have shaken Mayotte since its start in May — the largest being a magnitude 5.8, strong enough to be the largest in the island's recorded history — but no regular earthquakes were recorded where the enigmatic shaking took place in mid-November.
It's been proposed that, with what's known about the seismic swarm off the coast, the waves could've been caused by new volcanic activity emerging off Mayotte. This theory would compliment the fact that Mayotte has moved some 2.4 inches east and 1.2 inches south since the swarm began due to the movement of large amounts of magma, an analysis by the country's National Institute of Geographical and Forest Information suggests.
"These observations therefore back up the hypothesis of a combination of tectonic and volcanic effects accounting for a geological phenomenon involving a seismic sequence and a volcanic phenomenon," the BRGM wrote, adding that their hypothesis will have to be backed by future studies.
But for now, the cause of the mystery waves remains unknown.
It's nice to know that with everything we think we know about the universe, there are still mysteries back here. My vote is split between A) Cthulhu awakening B) The Hollow Earth theory is true and the under grounders were simply having a big ass party.
