In late 2018, geologists and seismologists were baffled by a mysterious seismic event unlike anything seen before. Some type of massive event literally shook the entire Earth, and scientists still aren’t quite sure what it could have been. A team of French researchers published a study of the seismic anomaly this week which offers a few clues about its origins, but the study ultimately poses more questions than it answers. What’s happening deep within the Earth?
The epicenter for the 2018 seismic anomaly was just off of the coast of Mayotte, a small archipelago in the Indian Ocean presided over by France. The event consisted of long pulses of extremely low frequency waves far below the threshold of human perception but quite powerful enough to register on seismological instruments. The pulses did not appear to be caused by earthquakes - at least any type of earthquake we know of - yet also did not appear to be man made.
To add to the mystery of the 2018 seismic anomaly, geologists have found that Mayotte is sinking by as much as 9 mm or .35 inches a month as well as drifting eastward at twice that rate. That observation seems to support the new hypothesis that the 2018 event was caused by an underwater volcanic event the likes of which we’ve never seen. In the new study of the event, researchers write that this event could be “the offshore eruption with the largest volume ever documented.”
The event is thought to have been caused over a cubic kilometer of magma 28 km (17 miles) below the ocean surface somehow flowed outward into surrounding sedimentary layers as opposed to flowing upward, hence why nothing was observed on the surface. If that’s true, though, it leaves a lot of unanswered questions about the event. In the months since the seismic anomaly, large fish kills have been observed; if all of the magma remained underground, what’s killing the fish? What is causing the high frequency pulses which were recorded alongside the low frequency rumbles? And could this activity be related to the island’s eastward and downward migration?
The 2018 seismic anomaly is only one example of recent disquieting developments in eastern Africa which suggest something big may be happening below the Earth’s surface. Last year, a massive crack was found to have formed in eastern Africa running through Kenya and Somalia, a crack which is pulling away from the rest of the continent at 2.5 cm or 1 inch per year. A few months earlier, scientists published a study of the so-called “South Atlantic Anomaly,” a strange and unexplained disturbance in the Earth’s magnetic field which suggests “there’s something unusual about the core-mantle boundary under Africa that could be having an important impact on the global magnetic field.”
Could all of these events and phenomena be related? What exactly is happening deep within the Earth under Africa? Do we really want to know, or is it better to be surprised in the middle of your breakfast burrito by the massive wall of magma rushing to engulf you and everyone you know? At least it wasn't a good breakfast burrito. That new girl on the taco truck always puts the cheese in a big clump right in the middle instead of spreading it out evenly throughout the whole burrito.
Life is just a series of disappointing burritos. Bring it on, magma. End it already.