Undersea origins of Earth’s mysterious Love waves

Supercomputer simulations of planetary-scale interactions show how ocean storms and the structure of Earth's upper layers together generate much of the world's seismic waves. Decoding the faint but ubiquitous vibrations known as Love waves could yield insights about Earth's storm history, changing climate and interior. Vibrations travel through our planet in waves, like chords ringing out from a strummed guitar. Earthquakes, volcanoes and the bustle of human activity excite some of these seismic waves. Many more reverberate from wind-driven ocean storms. As storms churn the world's seas, wind-whipped waves at the surface interact in a unique way that produces piston-like thumps of pressure on the seafloor, generating a stream of faint tremors that undulate through Earth to every corner of the globe. "There is an imprint of those three Earth systems in this ambient seismic data: atmosphere, Earth's rocky outer layers and ocean," said Stanford University geophysicist Lucia Gualtieri , lead author of a paper in Proceedings of the National Academy of Sciences that helps to resolve a decades-old conundrum over the physics of seismic waves related to ocean storms.