The fin whale is the second-largest animal ever to live on Earth. It is also, paradoxically（自相矛盾地）, one of the least understood. The animal's huge size and global range make its movements and behavior hard to study. A carcass（尸体，残骸） that washed up on a Seattle-area beach this spring provided a reminder that sleek fin whales, nicknamed "greyhounds of the sea," are vulnerable to collision when they strike fast-moving ships. Knowing their swimming behaviors could help vessels avoid the animals. Understanding where and what they eat could also help support the fin whale's slowly rebounding populations.

University of Washington oceanographers are addressing such questions using a growing number of seafloor seismometers, devices that record vibrations. A series of three papers published this winter in the Journal of the Acoustical Society of America interprets whale calls found in earthquake sensor data, an inexpensive and non-invasive way to monitor the whales. The studies are the first to match whale calls with fine-scale swimming behavior, providing new hints at the animals' movement and communication patterns.

The research began a decade ago as a project to monitor tremors on the Juan de Fuca Ridge, a seismically active zone more than a mile deep off the Washington coast. That was the first time UW researchers had collected an entire year's worth of seafloor seismic（地震的） data.

"Over the winter months we recorded a lot of earthquakes, but we also had an awful lot of fin-whale calls," said principal investigator William Wilcock, a UW professor of oceanography. At first the fin whale calls, which at 17 to 35 vibrations per second overlap with the seismic data, "were kind of just a nuisance（损害，麻烦）," he said.