October 23, 2012

Blame it on the rain: The proposed links between severe storms and earthquakes

The U.S. Geological Survey’s website states it in no uncertain terms: “There is no such thing as ‘earthquake weather.’”

Not too surprising, right? After all, how could the seemingly insignificant stresses imposed on the planet’s surface by mere weather instigate seismic shaking far underfoot? (Meteorologists measure atmospheric pressures in kilopascals; geophysicists measure tectonic pressures in mega- and gigapascals.) Earthquakes and heavy rainstorms do occasionally produce comparable results on the planet’s surface, devastating landscapes and impacting humans, but it’s hard to imagine any more of a connection between such disparate phenomena. The physical processes involved operate in different realms — below- versus above-ground — and predominantly on very different timescales: Stress builds on faults over the course of years, in some cases hundreds to thousands of years, whereas storm systems persist only for days or, in the case of seasonal monsoons, a few months.