Japan has lifted all tsunami warnings and advisories following a powerful magnitude 7.7 earthquake that struck off the northeastern coast of Honshu on Monday afternoon, April 20, 2026. The tremor, which occurred at 4:53 p.m. local time at a depth of 19 kilometers, initially triggered a major tsunami warning for Hokkaido, Aomori, and Iwate prefectures, with authorities bracing for waves of up to 3 meters. Residents in 182 coastal municipalities were urged to evacuate immediately to higher ground, evoking memories of the tragic 2011 disaster. However, after waves of approximately 80 centimeters were recorded at Kuji Port and smaller surges were observed elsewhere, the Japan Meteorological Agency (JMA) gradually downgraded and eventually canceled all alerts by Monday evening.
While immediate tsunami threats have subsided, Prime Minister Sanae Takaichi and the JMA have issued a rare “special advisory” regarding an increased risk of a subsequent mega-quake. Officials noted that the probability of a magnitude 8.0 or larger event along the Japan Trench has risen from the baseline 0.1% to roughly 1% over the next week. The government has urged citizens to remain vigilant, keep emergency “grab bags” ready, and re-confirm evacuation routes while continuing their daily activities. Despite the intensity of the shaking—which registered as an “upper 5” on Japan’s seismic scale—preliminary reports indicate only minor injuries and no significant damage to infrastructure or the region’s idled nuclear power plants. Bullet train services, which were temporarily suspended between Tokyo and Shin-Aomori, have begun to resume as safety checks are completed across the affected prefectures.
