Earthquake hits Japan
Friday morning’s 8.9 magnitude earthquake off the coast of Japan was unusual in more ways than one.
“It’s a historic earthquake,” said Rick Aster, principal investigator for IRIS Passcal, the geological consortium with offices in New Mexico Tech’s Research Park. “It’s one of largest earthquakes in Japan’s history, and possibly one of the top five in terms of raw power.”
There were tremendous aftershocks, which is common, but Aster said what was unusual was that there were tremendous foreshocks as well, including a magnitude 7.2 foreshock a couple of days earlier.
Foreshocks aren’t the norm, and aren’t a useful indicator of activity to come. In fact, Aster said, there was no way to predict what happened.
“Earthquakes are the last natural hazard for which we have no predictive capability,” he said.
Aster described the combination of the strong shaking and the tsunami as a tremendous blow to Japan.
“It’s fortunate that they were extremely well-prepared,” he said, referring to the country’s strict building codes. “We’re hoping that the deaths are limited to 1,000, at this point.”
The disaster was unique in another way, Aster said. “It’s the first time a highly modern country with a very sophisticated infrastructure has been hit with a quake of this magnitude,”
IRIS Passcal, he said, has seismic instruments all over the world, targeted for specific areas, but added that he doesn’t expect the consortium to be called on to provide data.
“The Japanese have a highly developed seismological capability,” he said. “They have the densest array of seismic equipment and instruments anywhere in the world. They will certainly follow up.”
But not, of course, until they’ve had a chance to deal with the immediate aftermath of the quake and tsunami.
“These giant earthquakes only happen a few times in a century,” Aster said. “We’re expecting to learn a lot about the response of a modern developed country and about the science of earthquakes.”
The more we learn, the better, because the next seismic event of this magnitude could happen a lot closer to home.
“This earthquake is not a bad analog for the giant earthquake that we expect to happen off the coast of northern California, Oregon and Washington, where there are similar fault lines,” Aster said. “You could call it a harbinger of what will eventually happen in the Pacific Northwest.”
Contact Suzanne Barteau