Superstorm Sandy Powerful Enough to Rock West Coast: Waves Shake Earth

When Superstorm Sandy roared ashore on October 30 last year, it didn't just cause flooding. It also shook the ground as far away as the West Coast, triggering seismometers monitoring the vibrations in the Earth's crust. Now, scientists have announced their findings about this massive storm at the Seismological Society of America's annual meeting.

Hurricane Sandy churned off of the East Coast last October. With howling winds and rains, meteorologists predicted it would land further south than it did. Instead, it swept northward, hooked left and then slammed ashore just northeast of Atlantic City, New Jersey. Once a Category 3 storm, it degenerated to a Category 2 storm off of the East Coast before finally turning into a tropical storm. That said, it was still impressive; it was the most destructive tropical cyclone of the 2012 Atlantic hurricane season and the second-costliest hurricane in United States history. It affected 24 states, and its storm surge flooded New York City's streets, tunnels and subway lines. Total damage estimates in the U.S. were about $71 billion.

Long before it made landfall, though, miniscule vibrations triggered in Earth's crust could be picked up on instruments onshore. In fact, these tremors were roughly similar to a magnitude-2 or magnitude3 earthquake; however, they had a unique signal on seismometers that were distinct from the rapid shaking caused by earthquakes. While some of the vibrations were actually produced by surf pounding beaches, a larger amount of these were actually from large storm waves far offshore slamming into each other.

"The turning of the storm created strong wave-on-wave interactions that increased the microseism energy," said Keith Koper, study co-author, in an interview with OurAmazingPlanet. "When the storm turned north of the Bahamas, we saw a bump in the microseismic energy, and when it took that sharp left-hand turn, we saw an even bigger bump."

These storm-induced vibrations aren't anything new, though. They were picked up in 2005 from Hurricane Katrina, and even storms far from land can trigger motions. Yet what is new is the fact that scientists are now recognizing the usefulness of this data, according to ScienceNow. The recorded vibrations could potentially be used to make images of large structures within Earth's crust and underlying mantle due to their large wavelengths.

Currently, the researchers are examining microseisms from Hurricane Sandy and other natural ocean sources as a tool to investigate climate change.

"Because these microseisms are happening all over the Earth, we could have a better understanding of climate, ocean and solid-Earth interactions," said Oner Sufri, lead study author, in an interview with LiveScience.com.