A magnitude-7.6 earthquake struck off Japan's northeastern coast near Aomori Prefecture at 23:15 JST Monday (14:15 UTC), prompting the Japan Meteorological Agency to issue tsunami warnings for Aomori, Iwate, and parts of Hokkaido with potential wave heights reaching 3 meters (approximately 10 feet), according to JMA. The agency ordered immediate coastal evacuations despite initial observed tsunami heights of only 40 centimeters (16 inches) at monitoring stations in Aomori and Hokkaido, emphasizing that later waves can exceed early readings and local coastal topography can amplify impact unpredictably.
The earthquake occurred approximately 80 kilometers offshore in the Sanriku region at a depth of roughly 50 kilometers, JMA reported. The U.S. Geological Survey placed the epicenter about 70 kilometers (44 miles) off the coast at 53 kilometers depth, parameters broadly consistent with Japanese assessments. Maximum shaking intensity reached upper 6 on Japan's zero-to-seven seismic scale in the hardest-hit areas, according to NHK citing JMA data.
Evacuation orders remain despite small initial waves
JMA has maintained evacuation guidance for coastal populations in Aomori, Iwate, and Hokkaido, instructing residents to move immediately to higher ground and stay away from coastlines and river mouths until an all-clear is issued. The agency emphasized that tsunami heights can significantly exceed initial estimates due to coastal geometry and that residents must not wait for visible water withdrawal before evacuating—a phenomenon that preceded the catastrophic 2011 Tohoku tsunami.
Tsunami advisories, indicating potential waves up to approximately 1 meter, remain in effect for Miyagi and Fukushima prefectures to the south. The Pacific Tsunami Warning Center indicated that "hazardous" tsunami waves are possible within 1,000 kilometers of the epicenter along the coasts of Japan and Russia, according to PTWC statements reported by Al Jazeera and Sky News.
The persistence of evacuation orders despite modest initial observations reflects lessons from Japan's 2011 magnitude-9.1 Tohoku earthquake and tsunami, which devastated the same northeastern coastline and triggered the Fukushima nuclear disaster. That event killed nearly 20,000 people and reshaped Japan's emergency protocols, instilling a conservative doctrine that prioritizes immediate evacuation over waiting to assess wave behavior. Japan sits on the Pacific "Ring of Fire," experiencing frequent significant seismic activity that has reinforced the importance of rapid, precautionary response.
The region has faced multiple natural disasters in recent months. Southeast Asia's monsoon season pushed death tolls past 1,000 as rescue capacity strained across multiple countries, while Typhoon Kalmaegi killed at least 114 in the central Philippines and landslides in Central Java claimed 30 lives amid persistent rainfall.
Members are reading: Why JMA maintains evacuation orders despite modest initial waves—the tsunami physics and 2011 lessons driving today's response.
Government mobilizes emergency response; infrastructure checks underway
Prime Minister Sanae Takaichi stated that the government is acting under the principle of putting human life first, coordinating closely with local officials to assess damage and mobilize emergency response resources. Nuclear power plants in the affected region are undergoing safety checks, though results have not yet been disclosed. Transportation services are experiencing disruptions across the northeastern prefectures, according to broadcast and wire reporting.
NHK reported several people injured at a hotel in Hachinohe, Aomori Prefecture, though details remain preliminary. A CNN team in Tokyo felt strong tremors lasting more than 30 seconds, illustrating the quake's reach across the Kanto region despite the epicenter's northeastern location.
JMA continues to monitor seismic activity and tsunami wave evolution, with updates expected as coastal monitoring stations track subsequent wave arrivals and aftershock sequences develop. Local governments will issue all-clear notices only after confirming that tsunami danger has fully subsided—a process that can take several hours following major offshore earthquakes. Residents in affected areas are advised to follow official guidance and avoid coastal zones and river mouths until authorities confirm it is safe to return.
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