Massive 7.7 Earthquake Hits Japan, Triggering Tsunami Warnings

A powerful earthquake struck off the northeastern coast of Japan today, Monday, April 20, sending shockwaves through coastal communities still carrying the memory of one of the deadliest natural disasters in recorded history. The Japan Meteorological Agency confirmed the quake at a magnitude of 7.7, striking at 4:53 p.m. local time at a depth of 20 kilometers in the Pacific Ocean, roughly 100 kilometers off the coast of Iwate Prefecture. Buildings swayed in Tokyo, hundreds of miles to the south, for nearly seven minutes.

Tsunami Warning Issued, Then Downgraded

Within minutes of the quake, the Japan Meteorological Agency issued an initial tsunami warning for Iwate Prefecture and parts of Hokkaido and Aomori, with waves of up to 3 meters, roughly 10 feet, expected to hit the coast. Authorities urged residents to evacuate immediately, broadcasting alerts to move to higher ground and stay away from coastal areas and river mouths.

Japan's disaster management agency issued evacuation orders to nearly 172,000 people across five prefectures. NHK footage showed ships sailing out of Hachinohe port as the warning alert flashed across screens: "Tsunami! Evacuate!" Bullet train services were suspended throughout Aomori Prefecture and across local train lines in Iwate.

As the hours unfolded, the actual wave heights measured significantly lower than the warning level. The largest recorded wave hit Kuji Port in Iwate Prefecture at approximately 80 centimeters, or about 2.6 feet. Smaller waves were detected at Miyako Port, Hachinohe, and Ishinomaki. By evening local time, the three-meter warning had been downgraded to a tsunami advisory, and Japan's top government spokesperson Minoru Kihara confirmed that no injuries or major structural damage had been reported. Around 200 power outages were being addressed across the affected regions.