Scientists have warned there could be a big increase in numbers of devastating earthquakes around the world next year. They believe variations in the speed of Earth’s rotation could trigger intense seismic activity, particularly in heavily populated tropical regions.
Although such fluctuations in rotation are small – changing the length of the day by a millisecond – they could still be implicated in the release of vast amounts of underground energy, it is argued.
The link between Earth’s rotation and seismic activity was highlighted last month in a paper by Roger Bilham of the University of Colorado in Boulder and Rebecca Bendick of the University of Montana in Missoula presented at the annual meeting of the Geological Society of America.
“The correlation between Earth’s rotation and earthquake activity is strong and suggests there is going to be an increase in numbers of intense earthquakes next year,” Bilham told the Observer last week.
In their study, Bilham and Bendick looked at earthquakes of magnitude 7 and greater that had occurred since 1900. “Major earthquakes have been well recorded for more than a century and that gives us a good record to study,” said Bilham.
From the article in science mag
The research started as a search for synchrony in earthquake timing. Individual oscillators, be they fireflies, heart muscles, or metronomes, can end up vibrating in synchrony as a result of some kind of cross-talk—or some common influence. To Bendick, it didn’t seem a far jump to consider the faults that cause earthquakes, with their cyclical buildup of strain and violent discharge, as “really noisy, really crummy oscillators,” she says. She and Bilham dove into the data, using the only complete earthquake catalog for the past 100 years: magnitude-7 and larger earthquakes.