There will be a significant rise in the number of devastating earthquakes around the world in 2018 because the speed of the Earth’s rotation has changed, said scientists studying the link between rotation and seismic activity.

Roger Bilham from the University of Colorado in Boulder and Rebecca Bendick from the University of Montana in Missoula presented a paper on the subject at the annual meeting of the Geological Society of America. Their study showed that while the changes in rotation were small – it will only alter the length of a day by a millisecond – they could still lead to the release of vast amounts of underground energy.

“On five occasions in the past century, a 25% to 30% rise in the number of earthquakes [of magnitude 7.0 or greater] has coincided with a slowing in the mean rotation velocity of the Earth,” the scientists said, after observing powerful earthquakes since 1900.

The Earth’s rotation began one of its periodic slowdowns more than four years ago, the researchers said, adding that the inference was clear then. “We have had it easy this year,” Bilham told The Guardian. “So far we have only had about six severe earthquakes. We could easily have 20 a year, starting 2018.”