Earthquake sensors can analyze fin whale song patterns
Fin whales are magnificent, but poorly-understood, endangered creatures. Understanding their songs would be one of the keys to making sense of why they act the way they do, and now a group of seismologists has just found a way to do that.The team said last week at the annual meeting of the American Geophysical Union, in San Francisco, that seismometers installed on the ocean floor to keep track of earthquakes and other ground movements can be used to keep track of how fin whales communicate.
What is interesting to note here is that these devices have always picked up the whales' songs. Until now, experts analyzing tremors simply removed these recordings from their datasets, in order to be left with the signals released by the crust exclusively.
But the whales also produce booming calls, which are recorded by the instruments in nearly-perfect conditions. What the new study did was check to see how these datasets looked like once the seismology-related data were removed from the equation.
Surprisingly, scientists at the University of Washington in Seattle (UWS) say that they are left with extremely useful datasets, which may help them figure out the elusive animals' social habits, breeding grounds, and seasonal migration patterns, among other things.
One of the reasons why fin whales are so little-understood is that they tend to keep to themselves, in the waters of the deep ocean, far below the surface. Radio-tagging and visual survey – the two most commonly used methods of tracking whales – are very expensive and difficult in such conditions.
UWS seismologist and team leader William Wilcock says that his team used filters to remove the ground rumblings from all the recordings. They did so by reversing the function of existing filters, previously used to cull the whale songs from the data.
Most of the data the team used in their research were collected from near the Juan de Fuca Ridge, close to Vancouver Island, Canada. This is where fin whales tend to come together, near the Endeavour hydrothermal vents. A total of about 300,000 calls were recorded over the course of 3 years.
The disposition of the 8 sensors the team had access to allowed them to pinpoint the position of each fin whale that made a call within an area of 500 meters (1,640 feet) across, ScienceNow reports.
The group has already extracted some data from the new readings, but scientists plan to conduct even more in-depth studies in the future. The researches may finally provide more insight into these amazing creatures.