"We detected seismic waves created by the ocean's waves both hitting the East Coast and smashing into each other," with the most intense seismic activity recorded when Sandy turned toward Long Island, New York and New Jersey, Keith Koper, director of the University of Utah Seismograph Stations, said.
Oner Sufri, a Utah doctoral student who co-authored a study with Koper, was in Salt Lake City Thursday for the Seismological Society of America's annual meeting.
"We were able to track the hurricane by looking at the 'microseisms' [relatively small seismic waves] generated by Sandy," Sufri said. "As the storm turned west-northwest, the seismometers lit up."
Some of the shaking was caused by waves hitting the East Coast but much more was the result of waves colliding with other waves in the ocean, setting up "standing waves" that reach the seafloor and transmit energy to it, Sufri and Koper said.
Sandy's microseisms ranged from roughly 2 to 3 on an earthquake magnitude scale, Koper said, adding a conversion is difficult because earthquakes pack a quick punch while storms unleash their energy for many hours.
While seismologists didn't track Sandy in real time, he said, the seismographic data of the storm suggests it might be possible to help track ocean storms in the future using their seismicity.