In a new research, scientists have determined that Earth’s tides may help predict some of the most violent earthquakes on the planet.
As tectonic stresses build along a fault, researchers have long suspected that Earth’s crust would show some sign that it is about to break. They have examined everything from radon levels in groundwater to changes in the electrical properties of the ionosphere, but earthquake prediction remains tantalizingly out of reach.
But, according to a report in Discovery News, one researcher, Sachiko Tanaka of the National Research Institute for Earth Science and Disaster Prevention in Japan, has quietly built a case that giant quakes may be predictable using Earth’s tides.
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Scientists have found that tides - the combined effects of the weight of the ocean and gravitational pull of the sun and moon - do have a small but noticeable influence on earthquake behavior.
In a new study, Tanaka analyzed 1,126 earthquakes up and down the fault zone off Sumatra, where the Eurasian tectonic plate grinds beneath the Australian plate.
In the years before the 2004 mega quake, she found that smaller tremors were increasingly triggered by Earth’s tides. That same pattern held for two later quakes to the south of the 2004 event, a magnitude 8.6 temblor in 2005 and a magnitude 8.5 in 2007.
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“These results suggest that tidal triggering may appear only when the stress in the focal region is close to a critical condition to release a large rupture,” Tanaka said.
In other words, as a fault zone winds ever tighter with stress and gets ready to pop, tides start causing more and more small earthquakes.
Thus, tide-triggered quakes could one day become a potent tool for moving people out of harm’s way and saving thousands of lives.