Tiny tremors can track extreme storms in a warming planet

Terra Daily: Data from faint earth tremors caused by wind-driven ocean waves-often dismissed as "background noise" at seismographic stations around the world-suggest extreme ocean storms have become more frequent over the past three decades, according to research presented at the annual meeting of the Seismological Society of America.

The International Panel on Climate Change (IPCC) and other prominent researchers have predicted that stronger and more frequent storms may occur as a result of global warming trends. The tiny tremors, or microseisms, offer a new way to discover whether these predictions are already coming true, said Richard Aster, a geophysics professor at the New Mexico Institute of Mining and Technology.

Unceasing as the ocean waves that trigger them, the microseisms show up as five- to 30-second oscillations of Earth's surface at seismographic stations around the world. Even seismic monitoring stations "in the middle of a continent are sensitive to the waves crashing all around the continent," Aster said. As storm winds drive ocean waves higher, the microseism signals increase their amplitude as well, offering a unique way to track storm intensities across seasons, over time, and at different geographical locations….

Ocean waves photo by Sean O'Flaherty (aka Seano1), Wikimedia Commons, under the Creative Commons Attribution ShareAlike 2.5 License.