On the morning of November 11, 2018 simply earlier than 9:30 UT, a mysterious rumble rolled around the world.
The seismic waves started roughly 15 miles off the shores of Mayotte, a French island sandwiched between Africa and the northern tip of Madagascar. The waves buzzed throughout Africa, ringing sensors in Zambia, Kenya, and Ethiopia. They traversed huge oceans, buzzing throughout Chile, New Zealand, Canada, and even Hawaii practically 11,000 miles away.
These waves did not simply zip by; they rang for greater than 20 minutes. And but, it appears, no human felt them.
Only one individual observed the odd sign on the U.S. Geological Survey’s real-time seismogram shows. An earthquake fanatic who makes use of the deal with @matarikipax noticed the curious zigzags and posted photos of them to Twitter. That small motion kicked off one other ripple of types, as researchers around the world tried to suss out the supply of the waves. Was it a meteor strike? A submarine volcano eruption? An historic sea monster rising from the deep?
“I don’t think I’ve seen anything like it,” says Göran Ekström, a seismologist at Columbia University who makes a speciality of uncommon earthquakes.
“It doesn’t mean that, in the end, the cause of them is that exotic,” he notes. Yet many options of the waves are remarkably bizarre—from their surprisingly monotone, low-frequency “ring” to their international unfold. And researchers are nonetheless chasing down the geologic conundrum.