Coastwide
In August 2009, Hurricane Bill (shown) tracked northwest from Puerto Rico toward Newfoundland in Canada. As it passed offshore of New England, the winds churned up the ocean. The forces interacted with the seafloor to create stormquakes. JEFF SCHMALTZ/MODIS RAPID RESPONSE TEAM/NASA GODDARD SPACE FLIGHT CENTER

Powerful storms may be causing ‘stormquakes’ offshore

Strong ocean swells hammer ridges in the seafloor — producing earthquake-like shakes

Powerful hurricanes can whip the ocean into a frenzy. That wave energy hammers the seafloor. Sometimes it can be strong enough to produce a novel kind of quake, new research reveals.

Wenyuan Fan led the new research. He’s a seismologist at Florida State University in Tallahassee. His team described these stormquakes online October 14 in Geophysical Research Letters. These tremors are a newly identified type of interaction between Earth’s atmosphere, ocean and crust.

Stormquakes differ from earthquakes. Earthquakes are triggered by subsurface shifting within the solid Earth. The driving force behind stormquakes are ocean waves that have been whipped into deep swells by a hurricane or nor’easter. Stormquakes can be as powerful as a magnitude 3.5 earthquake, the new report says. That’s a level barely noticeable to people but detectable by seismometers.

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