Tsunami Moved Too Quickly for Warning System
All Things Considered, April 2, 2007 · The deadly tsunami that hit the Solomon Islands early Monday (4:39 p.m. Sunday EDT) struck faster than scientists could warn residents, despite an elaborate tsunami warning system that spans the entire Pacific. Scientists say earthquakes close to shore create tsunamis that move too fast for their seismic network to pinpoint.
The tsunami that struck the Solomons, in the western Pacific, has reportedly taken more than 12 lives. And there are local accounts of dozens more people missing. Witnesses described waves at least 10 feet high sweeping over parts of the islands, washing away houses and people.
Within about 15 minutes of the quake, the Pacific Tsunami Warning Center in Hawaii sent out a warning saying it could create a tsunami. The warning goes out electronically to scientists and public safety officials around the world.
But the quake, with a magnitude of 8.1, struck only about 30 miles from the Solomon Islands — which means that the tsunami probably rolled onto land within five minutes of the quake, according to geophysicist Barry Hirshorn.
Hirshorn says that in Hawaii, "We can issue a warning in about three minutes" because of its extensive system.
But the Solomon Islands doesn't have that kind of sophisticated warning system. Installing one would require dozens of costly tide gauges and tsunami detectors.
Scientists say they have measured some 20 good-sized aftershocks since the quake. And although the tsunami threat has subsided for the moment, they say the quake could have created stress in nearby faults — which could lead to more undersea earthquakes.