When Hurricane Sandy roared ashore on the Northeast coast last October, it not only caused flooding, but it also shook the ground as far away as the West Coast, triggering seismometers monitoring vibrations in the Earth's crust.
Scientists announced their findings about the massive storm at the Seismological Society of America's annual meeting, which wraps up today in Salt Lake City.
Hurricane Sandy slammed ashore just northeast of Atlantic City, N.J., on Oct. 30 as a Category 2 storm and became the most destructive tropical cyclone of the 2012 Atlantic hurricane season and the second-costliest hurricane in U.S. history. Total damage estimates in the United States were about $71 billion.
Long before it made landfall, though, minuscule vibrations triggered in the Earth's crust could be picked up on instruments onshore. Sandy's fateful left turn Oct. 29 toward the mid-Atlantic coast lit up earthquake monitors all the way to Seattle, according to results presented at the SSA meeting.
The earthquake-detection network picked up waves pounding the Atlantic coastline, but the energy from colliding ocean waves was much more powerful, Keith Koper, study co-author and director of the University of Utah Seismograph Stations, told OurAmazingPlanet.com.
The sudden increase in crashing ocean waves sent rumbles through the Earth that were detectable on seismometers. The wave-on-wave collisions created what are called standing waves, doubling the energy directed at the seafloor, scientists reported.
"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," Koper said.