rki.news | Sources: Xinhua

TOKYO: The Japan Meteorological Agency has revised the magnitude of the powerful earthquake that struck northeastern and northern Japan on Monday afternoon to 7.7, up from an initial estimate of 7.5.

Tsunami waves were observed along the Pacific coasts of Hokkaido, Aomori Prefecture and Iwate Prefecture. Officials reported an 80-centimeter wave at Kuji Port and a 40-centimeter wave at Miyako Port.

Emergency services said a man in his 60s in Hachinohe, Aomori Prefecture, was hospitalized after falling at his home during the tremor, according to local reports.

Evacuation orders were issued for more than 170,000 residents across Hokkaido, Aomori, Iwate, Miyagi and Fukushima prefectures, with authorities urging people to move to higher ground immediately.

Operators confirmed no abnormalities at nuclear facilities including the Higashidori, Onagawa, Fukushima Daiichi and Fukushima Daini plants.

The quake also disrupted transportation, including suspension of Tohoku Shinkansen bullet train services between Tokyo and Shin-Aomori.

The earthquake struck at 4:53 p.m. local time off the Sanriku coast at a depth of 20 kilometers, initially measured at magnitude 7.4 before being revised twice upward.

The agency warned that aftershocks of similar strength could occur in the coming week as monitoring continues.