Japan Braces for More Damage After Powerful 7.5 Quake, ‘Megaquake’ Alert Issued

Japan is on high alert after a powerful 7.5 magnitude earthquake struck on Monday, triggering dozens of aftershocks and prompting the Meteorological Agency to warn of a potential “megaquake.” Around 30 people were injured, and 90,000 residents were forced to evacuate.

A tsunami warning predicting waves up to 3 metres (10 feet) was issued for the country’s northeastern coast, though the alert was later downgraded to an advisory and eventually lifted early Tuesday.

Japan Earthquake: Key Points

• Japan’s Meteorological Agency has issued a caution about a possible megaquake following Monday’s powerful tremor.

• The quake, initially reported as magnitude 7.6, was revised to 7.5.

• Authorities issued a tsunami warning for waves up to 3 metres before downgrading and lifting it.

• The epicenter was located 80 km off Aomori prefecture, at a depth of 54 km.

• A separate 5.1 magnitude quake was recorded early Tuesday by the U.S. Geological Survey, south of Honcho.

• At least 23–30 people were injured, according to Japan’s disaster agency and PM Sanae Takaichi. Many injuries resulted from falling objects.

• 200 passengers were stranded overnight at New Chitose Airport in Hokkaido.

• 480 people sheltered at Hachinohe Air Base; 18 defense helicopters were deployed to assess damage.

• An emergency team has been set up to evaluate the impact, PM Takaichi said, urging residents to follow official updates.

No Abnormalities at Nuclear Plants

Shortly after the quake, Tohoku Electric Power confirmed that safety systems at the Higashidori nuclear plant in Aomori and Onagawa plant in Miyagi showed no irregularities—a critical reassurance in a region still haunted by the 2011 magnitude 9.0 disaster that killed nearly 20,000 people and crippled the Fukushima Daiichi plant.

Long-Term Megaquake Concerns

Japan’s government has long warned of a major seismic event. In January, a national panel raised the probability of a severe Nankai Trough earthquake in the next 30 years to 75–82%.
A later government projection estimated that a future megaquake and tsunami could cause 298,000 deaths and $2 trillion in economic damage.

A High-Risk Nation

Situated on the volatile Ring of Fire, Japan experiences a tremor roughly every five minutes, accounting for nearly 20% of the world’s earthquakes of magnitude 6.0 or higher.

Authorities continue to urge vigilance as aftershocks persist and seismic risks remain elevated.