S At first, the whale chatter was just a nuisance.
When Seattle scientists set out to monitor earthquakes off the Northwest coast,
they expected their underwater seismometers to occasionally pick up the booming
voice of the fin whale -- the second-largest creature on Earth. But what they
wound up with was such a cacophony that they had trouble zeroing in on the
actual tremors.
"It was a very big pain," said William Wilcock, a marine geophysicist at the
University of Washington.
To separate tens of thousands of small quakes from hundreds of thousands of
whale calls, he and his students were forced to write their own automated
program. Now, they're mining that mountain of discarded data for insights into
one of the sea's least-known and most endangered giants.
"Basically, we can track the whales using techniques very similar to the ones we
use to locate earthquakes," Wilcock said.
Second only to blue whales in size, fin whales remain shrouded in mystery
because they're so challenging to study. Nobody knows where they give birth or
even why they sing.
"When I started this project, I was really surprised by how little is actually
known about them," said doctoral student Michelle Weirathmueller. With seafloor
seismic monitoring on the rise, her goal is to fill in some of those gaps.
"The thing that's neat about this is that we are basically piggybacking on
experiments that were designed for something completely different," she said.
Already, the UW team has discovered that some fin whales migrate north in the
fall -- a time when biologists assumed most of the whales would be headed south
to breed.
Learning more about the species' movements, behavior and communication patterns
could bolster efforts to protect fin whales from further harm, now that they are
beginning to rebound from decades of whaling, said John Calambokidis, whale
biologist and co-founder of the Olympia-based Cascadia Research Collective.
A recent study found that fin and blue whales are more likely to be struck by
ships than any other whale species on the West Coast, he pointed out.
Puget Sound residents got a gory demonstration last month, when part of a
fin-whale carcass washed up on a beach near Burien. Scientists said the animal
was killed by a ship and dragged into the sound.
Usually, fin whales stick to deep water offshore _ which is one of the reasons
they haven't been studied much, Calambokidis said. Tagging and tracking is
expensive, and so are ship-based expeditions to observe and follow whales.
Fixed arrays of seismic instruments offer a promising alternative.
"It's clearly going to be an important and very-cost effective future
direction," he said.
Reaching up to 85 feet in length and weighing in at up to 80 tons, fin whales
earned the nickname "greyhounds of the sea" because of their sleek build and
explosive speed. They also produce some of the loudest noises in the animal
kingdom.
"It's just this amazing sound," Weirathmueller said.
The whales let loose with their short, basso profondo blasts roughly every 25
seconds, often continuing for a day or more. They pause only to breathe. The
pattern is so regular that scientists who first recorded the song thought it was
coming from some man-made device.
The whales' calls can travel thousands of miles through water. If unleashed on
