TOKYO — A powerful 7.8-magnitude earthquake struck off the northern coast of Hokkaido at 3:47 AM local time on Thursday, prompting the Japan Meteorological Agency to issue a Level 4 tsunami warning — the second-highest category — for the Hokkaido and Tohoku Pacific coastlines.
Authorities began evacuating an estimated 340,000 coastal residents within minutes of the tremor, with sirens sounding in fishing towns and seaside communities as emergency vehicles broadcast evacuation orders through loudspeakers. The Japan Coast Guard deployed three patrol vessels and four helicopters to monitor the shoreline.
Initial Reports
The earthquake's epicentre was located 80 kilometres east-southeast of Kushiro at a depth of 31 kilometres, according to the US Geological Survey. The shallow depth contributed to the tsunami risk. At the time of publication, no fatalities had been confirmed, and structural damage reports were still being compiled by prefectural authorities.
Japan's Self-Defence Force activated 2,400 personnel and pre-positioned rescue equipment at forward bases in Hokkaido. Prime Minister Takahiro Nishida convened an emergency cabinet meeting at 4:30 AM and urged residents to remain at evacuation centres until the all-clear was issued.
The first waves were forecast to arrive at coastal areas between 4:45 and 5:15 AM. JMA officials said the warning would remain in place for a minimum of three hours after initial wave contact.