viernes, 22 de mayo de 2009
Global Warming Now Audible, Study Says
Waves crash at Blackpool, U.K., in 2008. A May 2009 study says earthquake-station recordings can be used to trace global warming, because they register the sounds of crashing waves. The waves are indications of storms at sea, which many scientists believe are increasing due to rising temperatures.
Let's hope global warming doesn't go to 11. Now that climate change appears to be audible, that Spinal Tap-ian benchmark may someday be the ultimate gauge of climate catastrophe.
According to a new study, it's now possible to hear the rise of global warming in the form of more, larger, more intense storms—signs of climate change, many scientists say.For decades, seismologists have been filtering out the sounds of massive, storm-driven ocean waves crashing into coastlines. The pesky noise was getting in the way of earthquake detection.
But now some experts are electronically filtering out the quakes—and turning up the volume on the storm waves.
The noise of waves crashing ashore creates very specific vibrations, according to study leader Peter Bromirski of the Scripps Institution of Oceanography. And those vibrations indicate how severe storms at sea actually are.
Bromirski and others are still studying seismological data on storms from the 1930s to the present and are waiting to release the full analysis to the public.
But a trend is already obvious, he said. "There is a definite increase in severe storm events over the years that we are noticing at the recording stations."
The world stage is very well set for full-scale eavesdropping on open-ocean storm waves.
Seismic recording stations have been monitoring the vibrations of the Earth worldwide since the 1930s in roughly the same way.
That consistency may be reassuring to scientists. For example, weather-satellite data have been used to identify evidence of a trend of intensifying storms, but some scientists say satellite tech, having changed so much over the decades, is problematic for tracking storms in the long term.
"The nice thing about these [quake] recording stations," Bromirski said, "is that they are such stable devices that so consistently measure the vibrations produced by storm activity."