Japan on high alert for ‘huge’ second quake after issuing tsunami warning

Earthquake and Initial Response

A 7.7-magnitude tremor near Japan’s northeastern coast has prompted officials to heighten preparedness for a potential “major” follow-up quake within the coming days. The seismic event, which occurred in waters off Iwate prefecture, 530km north of Tokyo, led to evacuation orders and alerts for tsunami waves up to 3 meters high. While the largest recorded wave reached 80cm, the meteorological agency noted the possibility of stronger quakes in the near future, which could generate larger waves.

Regional Impact and Public Reaction

Tsunami warnings were extended to areas closest to the epicenter, including Honshu and Hokkaido. In Hokkaido, alerts remained active two hours after the quake struck at 16:52 local time. Chaw Su Thwe, a Myanmar resident in the region, described the scene: “As soon as we heard the earthquake alert, everyone ran downstairs.” She noted the shaking was milder than previous events, though authorities are now using loudspeakers to urge residents to remain vigilant. Office workers in affected zones were allowed to leave early as a precaution.

“Tsunami waves are expected to hit repeatedly. Do not leave safe ground until the warning is lifted,” said Japan’s Meteorological Agency (JMA) in the aftermath of the quake. Prime Minister Sanae Takaichi echoed this advice, emphasizing the need for people to seek higher, safer locations.

Infrastructure and Damage Reports

Japan’s Cabinet Secretary, Minoru Kihara, reported disruptions to several bullet trains and power outages affecting 100 homes. However, no significant damage or injuries were immediately reported. The tsunami warning was later reduced to an alert, signaling a lower but still present risk. The JMA highlighted that the likelihood of an 8.0 or stronger earthquake has now surpassed typical levels.

Historical Context and Seismic Activity

Japan’s position on the Ring of Fire exposes it to frequent seismic events, with approximately 1,500 quakes annually. The country accounts for 10% of all 6.0-magnitude or higher earthquakes globally. The 2011 disaster, a 9.0-magnitude quake off Iwate province, remains a stark reminder of the region’s vulnerability. That event triggered a massive tsunami and the Fukushima nuclear meltdown, which are among the worst in history. Since then, the government has prioritized early warnings to ensure residents can reach elevated ground swiftly.