Geologists predict the Earth could see about twice as many earthquakes this year because the world is turning a little slower than usual, prompting the equator to shrink slightly.
Our planetary spin cycle changes constantly — ocean currents and atmospheric changes have an impact, as do the mantle and molten core under them. But the current pattern has a team of geologists worried about earthquakes.
Professors Roger Bilham and Rebecca Bendick warn that the Earth’s slowing could lead to more than twice as many 7-plus-magnitude quakes in 2018.
Bilham, who studies earthquakes at the University of Colorado, told Business Insider that when the Earth’s pace lags for years at a time, its middle contracts. That shrinks the equator , but it’s hard for the tectonic plates that form Earth’s outer shell to adjust accordingly.
Instead of falling in line with the slimmer waistline, the edges of those plates get squeezed together.
This all takes time for us to feel on the ground. But after five years without many high-intensity quakes, we’re approaching the moment when the effects of this squeeze could be felt around the globe, Bilham said. He estimates the planet could see, on average, 20 high-magnitude earthquakes for each of the next four years. (By comparison, just seven earthquakes registered above a 7.0 in 2017.)