TOKYO, Japan — Authorities in Japan have warned of an increased risk of a major earthquake in the coming days after a powerful 7.7 magnitude tremor struck off the country’s north-east coast, triggering tsunami alerts and mass evacuations.
The undersea quake hit waters off Iwate Prefecture, about 530 kilometres north of Tokyo, prompting officials to order thousands of residents in coastal areas to move to higher ground amid fears of waves reaching up to three metres.
The Japan Meteorological Agency (JMA) said the largest waves recorded were about 80 centimetres but cautioned that stronger seismic activity could follow.
“We cannot rule out earthquakes causing even stronger shaking in the next week,” the agency said, later warning that the likelihood of a quake measuring magnitude 8.0 or higher is now “relatively higher than during normal times.”
Tremors from the quake, which struck at a depth of about 10 kilometres, were felt across a wide area, including parts of Honshu and Hokkaido, where tsunami alerts remained in place hours after the event.
Residents described scenes of urgency as warnings were broadcast through emergency systems. “As soon as we heard the earthquake alert, everyone ran downstairs,” said Chaw Su Thwe, a resident in Hokkaido, adding that authorities used loudspeakers to urge continued vigilance.
Infrastructure disruptions were reported, with bullet train services affected and about 100 homes experiencing power outages, according to Chief Cabinet Secretary Minoru Kihara. However, there were no immediate reports of major damage or casualties.
A tsunami warning—Japan’s second-highest alert level—was issued along sections of the eastern coastline, with officials urging residents to remain in safe locations until the advisory was lifted.
“Tsunami waves are expected to hit repeatedly. Do not leave safe ground,” the JMA said, a message echoed by Prime Minister Sanae Takaichi, who urged citizens to seek higher, safer ground.
Japan, located along the seismically active Pacific “Ring of Fire,” experiences around 1,500 earthquakes annually and accounts for roughly 10pc of the world’s major quakes.
The latest warnings have revived memories of the devastating 2011 Tōhoku earthquake and tsunami, which killed more than 18,000 people and triggered a nuclear meltdown at Fukushima Daiichi Nuclear Power Plant.
Since that disaster, Japan has strengthened its early warning systems and evacuation protocols, with authorities emphasising preparedness as the key defence against future seismic threats.
Officials say the coming days will be critical as monitoring continues for aftershocks and the potential escalation of seismic activity.
