CALLS FROM THE DEEP

摘要

Even without the beard, Christopher Fox would look nothing like Jodie Foster. Yet as he sits in his office trying to zero in on mysterious sounds emanating from far away, I'm reminded of the scene in Contact where Foster is sitting on her car, wearing headphones and listening for a message from outer space. Only in this case, Fox is tuned in to unidentified noises from the deep ocean, sounds with strange names like Train, Whistle, Slowdown and Bloop. "Just when you think there're no mysteries left in this world, we have a whole bucket of them on the screen here," says Fox, who directs the US National Oceanic & Atmospheric Administration's Acoustic Monitoring Project at the Pacific Marine Environmental Laboratory in Newport, Oregon. Earth's oceans are full of noise: boats, whales, submarines and earth tremors all add to the aquatic cacophony. The study of ocean acoustics has helped scientists monitor whale communication and migration, pinpoint the locations of undersea earthquakes and volcanoes, and even measure ocean temperatures, yet there's still a handful of sounds that continue to baffle researchers. They are generally very low-frequency and must be speeded up to be audible. Some last just a few minutes, while others go on continuously for years at a time. Nobody knows for sure what causes these sounds, but suspicion has fallen on volcanoes, icebergs and even huge, undiscovered beasts.