30 INJURED IN MAGNITUDE 7.5 QUAKE IN NORTHEAST JAPAN, GOV'T WARNS OF BIGGER TEMBLOR

TOKYO, Dec 9 (Bernama-Kyodo) -- A powerful quake with a magnitude of 7.5 struck northeastern Japan late Monday night, injuring 30 people and triggering tsunami waves as high as 70 centimetres that reached the Pacific coast, Kyodo News Agency reported, citing the Japanese government.

The Japan Meteorological Agency said the quake, which occurred at 11.15 pm off the eastern coast of Aomori Prefecture at a depth of 54 kilometres, could be followed by a temblor of similar or higher magnitude in the same area in the coming days.

It is the first time that the agency has issued such an alert for the coastal regions of Hokkaido and the Sanriku coast, which extends from Aomori through Iwate and Miyagi prefectures.

Prime Minister Sanae Takaichi called on people in the region to remain alert for information from local governments and the weather agency over the next week or so and to prepare for another possible quake, including by securing furniture.

“The government asks residents to continue social and economic activities while maintaining a readiness to evacuate immediately if any shaking is felt,” Takaichi told reporters Tuesday at her office in Tokyo.

The injuries were reported in Aomori Prefecture and Hokkaido.

The quake occurred in an area along a trench running off the coast of Hokkaido and northeastern Japan, where major quakes can be triggered as the Pacific plate subducts beneath the Honshu main island, according to the agency.

The agency, which revised the magnitude from an earlier reported 7.6, warned of a tsunami of up to 3 metres following the quake. The highest tsunami waves observed were 70 cm in Iwate.

Three and a half hours after the quake struck, the tsunami warning was downgraded to an advisory, which was lifted at 6.20 am Tuesday.

The quake logged upper six on the Japanese seismic intensity scale of 7 in parts of Aomori, a level at which it is impossible to remain standing or to move without crawling.

A special weather agency alert for a massive quake along the trench, called “Off the Coast of Hokkaido and Sanriku Subsequent Earthquake Advisory,” is issued following an earthquake with a confirmed magnitude of 7.0 or greater.

The agency assesses there is a one-in-100 chance that a Magnitude 8.0 quake or greater could occur within seven days.

But even when such an alert is in effect, the authorities do not call on the public to evacuate in preparation.

-- BERNAMA-KYODO