Japan quake prompted tsunami watch

By Jan TenBruggencate
Advertiser Staff Writer

A powerful earthquake off Hokkaido, Japan, at 9:50 a.m. yesterday created a couple of tense hours in Hawai'i until scientists determined it had not generated a Pacific-wide tsunami.

Reports from Japan indicated there were local tsunami and direct damage from the quake, which was in the Japan Trench region, about 40 miles below the surface. It was one of the most powerful earthquakes of the year worldwide, with a magnitude of 8.0. As a comparison, the southern Chile quake of 1960, which produced a tsunami that devastated Hilo, had a magnitude of 9.5.

The greatest fear of earthquake experts here yesterday was that the quake would generate an undersea landslide, said Stuart Weinstein, a geophysicist with the Honolulu-based Pacific Tsunami Warning Center.

"I don't think even an 8.1, in and of itself, could pump enough energy into the ocean to create a Pacific-wide tsunami, although it could produce a very large local tsunami," he said. But a big undersea slide could launch a tsunami that could cause damage thousands of miles away.

Weinstein said communications with state Civil Defense officials appeared to run smoothly yesterday.

The state and all four counties activated their civil defense emergency centers with the 11:11 a.m. tsunami watch issued by the Pacific Tsunami Warning Center. The watch was canceled at 12:14 p.m.