Japanese authorities have raised concerns over the possibility of a major earthquake within the coming week, following a powerful 7.7-magnitude tremor off the country’s north-eastern coast that prompted evacuations and tsunami warnings.
The quake struck in waters near Iwate Prefecture, about 530km north of Tokyo, forcing thousands of residents in coastal communities to move to higher ground amid fears of tsunami waves reaching up to three metres.
Although the highest waves recorded measured 80cm, Japan’s meteorological agency cautioned that stronger seismic activity could still occur in the days ahead, potentially generating larger waves.
The agency later warned that the likelihood of an earthquake of magnitude 8.0 or higher is now “relatively higher than during normal times”.
The alert has revived memories of the devastating 2011 disaster, when a massive earthquake and tsunami killed more than 18,000 people and triggered a nuclear meltdown at Fukushima.
Monday’s undersea quake, which occurred at a depth of 10km, led to warnings for residents in areas closest to the epicentre, including parts of Honshu and the northern island of Hokkaido. Tremors were also felt in Tokyo.
In Hokkaido, tsunami alerts remained active for about two hours after the quake struck at 16:52 local time.
“As soon as we heard the earthquake alert, everyone ran downstairs,” Chaw Su Thwe, a Myanmar national living in Hokkaido, told the BBC. “However, this time the shaking was relatively mild.
“Right now, local authorities are using loudspeakers in the neighbourhood to warn people about a possible tsunami and to stay alert,” she added. “Office workers have been allowed to leave work early.”
Authorities reported disruptions to transport services, including some bullet trains, while about 100 homes experienced power outages, according to Japan’s Cabinet Secretary Minoru Kihara.
There were no immediate reports of significant damage or casualties.
A tsunami warning, the second-highest alert level, was issued for parts of Japan’s eastern coastline, urging residents in coastal and riverside areas to evacuate immediately to higher ground or designated safe buildings.
“Tsunami waves are expected to hit repeatedly. Do not leave safe ground until the warning is lifted,” Japan’s Meteorological Agency (JMA) told reporters in the hours after the quake – a plea echoed by Prime Minister Sanae Takaichi, who urged people to get to “higher, safer places”.
The warning was later reduced to a lower-level alert and eventually lifted entirely before midnight.
Located along the seismically active Pacific Ring of Fire, Japan experiences around 1,500 earthquakes annually and accounts for roughly 10% of the world’s quakes of magnitude 6.0 or higher.
In March 2011, the country recorded its strongest-ever earthquake, a magnitude 9.0 tremor off the coast near Iwate, which led to a catastrophic tsunami and the Fukushima nuclear disaster.
Since then, authorities have maintained strict emergency response systems, consistently advising residents to seek higher ground during such threats.
