Giant Earthquake Jolts Japan, But Tsunami Warnings Cancelled

TOKYO, Japan, January 13, 2007 (ENS) - A tsunami warning that was in effect for Japan and Russia after a massive undersea earthquake shook the Pacific Ocean northeast of Japan this afternoon has been cancelled.

The earthquake was measured at a magnitude of 8.3 by the Japan Meteorological Agency and at a magnitude of 8.4 by the Pacific Tsunami Warning Center in Honolulu, Hawaii operated by the National Oceanic and Atmospheric Administration, NOAA.

The earthquake was recorded at a depth of 30 kilometers beneath the floor of the northwestern Pacific Ocean near a feature called the Chishima Trench.

But the largest wave reported was a 16 inch tidal swell that hit the shores of Chichi-jima, a Pacific island 620 miles south of Tokyo, about three hours after the quake.

The large orange box represents the latest earthquake. The smaller yellow boxes represent earthquakes that occurred within the past seven days. (Map courtesy USGS)

A one meter (three foot) tsunami wave was expected to hit the Pacific coast of Hokkaido Island and also the island's Okhotsk Sea coast.

An evacuation advisory was issued to households in 14 municipalities and thousands of Hokkaido residents gathered at community centers. But the largest wave was a 16 inch tidal swell that hit the shores of Chichi-jima, a Pacific island 620 miles south of Tokyo.

A tsunami advisory, weaker than a warning, was issued for most of Japan's eastern coast, the Japan Meteorological Agency said.

NOAA's West Coast and Alaska Tsunami Warning Center in Palmer, Alaska issued a tsunami warning for Alaska coastal areas in the Aleutian Islands chain from Dutch Harbor to Attu.

A tsunami watch was in effect for the British Columbia and Alaska coastal areas from the north tip of Vancouver Island, British Columbia to Dutch Harbor, Alaska.

The Pacific Tsunami Warning Center posted a tsunami warning for Russia, Japan, and the Pacific islands of Marcus, Wake, Midway and the Northern Maraianas.

A tsunami watch was posted for Taiwan, the Philippines, Indonesia, Hawaii, and the Pacific islands including Papua New Guinea.

An earthquake of this size has the potential to generate a destructive tsunami that can strike coastlines near the epicenter within minutes and more distant coastlines within hours, meteorologists in Hawaii said.