Science | November 4, 2017 9:00 am

Could Tracking Changes in the Earth’s Rotation Help Predict Major Earthquakes?

Scientists find minute slowdowns in planet's spin correlate to more extreme seismic activity.

Two geophysicists think that minute changes in the Earth’s rotation are enough to influence the timing of major earthquakes. And they argue that tracking these changes could help us predict when those major earthquakes will come, according to Science Magazine.

Over the past century, Earth’s slowdowns have correlated with a global increase in magnitude-7 and larger earthquakes, according to Roger Bilham of the University of Colorado and Rebecca Bendick at the University of Montana-Missoula. The spike, they claims, adds two to five more massive quakes than is typical.

The good news is these spikes happen well after the slowdown begins. In effect, Bilham claims, the Earth gives us almost a five year “heads up” about the arrival of more extreme seismic activity.

The first pattern Bilham and Bendick reported was that major quakes appear to cluster in time but not space. Second, the number of large earthquakes appears to peak at 32-year intervals. But definitive links between the two phenomenon is still unclear, however.

When our planet’s day lengths slightly change over decades, Earth’s magnetic field seems to develop a temporary ripple, the researchers say. They suspect that slight changes in the flow of the molten iron in the planet’s liquid outer core may be responsible.

Seismologists tend to agree that predicting earthquakes is still a dangerous, imprecise game. But other researchers say the correlation Bilham and Bendick found is “remarkable, and deserves investigation,” reports Science.

What could this mean for us? A more dangerous next few years, for starters. According to the researchers’ theory, beginning in 2018, Earth should expect five more major earthquakes a year than average.