Quake rumbles can help provide quick tsunami warningsApril 22nd, 2009 - 1:05 pm ICT by ANI
London, April 22 (ANI): A team of seismologists has developed an early-warning system that can gauge how long an earthquake rumbles, thus helping tsunami warnings to reach vulnerable coastlines within minutes.
Most tsunami-warning systems work by measuring an undersea earthquake’s magnitude, because those above magnitude 7.5 are considered highly likely to generate a tsunami.
However, it takes at least 30 minutes to measure this accurately.
Previous studies have shown that quakes that shake for a long time are more likely to produce a tsunami.
Now, according to a report in New Scientist, Anthony Lomax, a consultant seismologist based in Mouans-Sartoux, France, and Alberto Michelini of the National Institute of Geophysics and Volcanology in Rome, Italy, have developed a way to spot this signature quickly.
The pair studied the seismic waves from 76 underwater earthquakes.
Sure enough, rumbles that produced high-frequency waves for more than 50 seconds had a high probability of generating a damaging tsunami wave.
Using this information, they developed an algorithm to filter out quake duration from seismic data.
If adopted in an early-warning system, “it could provide a warning within 10 to 15 minutes”, said Lomax.
“Used alongside other methods it could be promising,” said Emile Okal, a seismologist at Northwestern University in Evanston, Illinois.
The work will appear in Geophysical Research Letters. (ANI)
Tags: alberto michelini, coastlines, early warning system, evanston illinois, frequency waves, geophysical research letters, new scientist, northwestern university, okal, quakes, rome italy, seismic data, seismic waves, seismologists, tsunami warning systems, tsunami warnings, tsunami wave, undersea earthquake, underwater earthquakes, volcanology