Japan quake generates tsunami

A 6.9-intensity earthquake that rocked the east coast of Honshu, Japan, generated a tsunami, based on sea level readings, prompting residents on- and off-island to barrage the Emergency Management Office with telephone calls about the event. The EMO said no Pacific-wide tsunami occurred and the CNMI felt no unusual sea movements.

The EMO, however, maintained yesterday the high surf advisory that it issued Monday, warning beachgoers of hazardous surf rising up to 8 feet along the north, northeast and east exposures of Saipan, Tinian and Rota.

The EMO advised residents and tourists—including swimmers, divers and marine tour operators—to stay away from exposed reefs and beaches on the three islands, saying that rip currents, especially on the northeast coast, would be life-threatening to anyone entering the water.

The Japan quake occurred off the east coast of Honshu, approximately 220 miles east of Sendai and east-northeast of Tokyo. The EMO estimated the epicenter’s distance at 1,578 miles north of Saipan, 1, 602 miles north of Tinian, and 1,659 miles north of Rota. The EMO located the epicenter at about 1,348 miles north of Agrihan, 1,382 miles north of Pagan, and 1,420 miles north of Alamagan.

Preliminary reports indicate the quake’s magnitude at 7.3, but the U.S. National Earthquake Information Center later placed the temblor’s intensity at 6.9. EMO public information officer Ben Cepeda said a tsunami is usually generated after the occurrence of earthquakes with a magnitude of 7.5 or over.

“We received many calls about the possible tsunami,” said EMO public information officer Ben Cepeda. The EMO dismissed any tsunami threat to the Northern Marianas.

But the National Oceanic Atmospheric Administration’s Pacific Tsunami Warning Center reported that the quake generated a tsunami based on sea level readings.

The PTWC said the tsunami might have been destructive along coasts near the epicenter, but said local authorities could assume that the threat had passed after two hours if no gigantic waves were observed along the coasts.

“No tsunami threat exists for other coastal areas in the Pacific, although some other areas may experience small sea level changes,” the PTWC said in advisory issued at about 9:12am, CNMI time.