Japan quake and tsunamis
- A 7.5‑magnitude earthquake off Japan’s east coast triggered tsunami and evacuation advisories on April 20–21. (timeout.com) - Tsunami warnings named Hokkaido, Aomori, Iwate, Miyagi and Fukushima, and some ports recorded waves up to 80 cm. ( ) - The U.S. embassy urged Americans to monitor official channels, and Japan’s nuclear authority reported no coastal plant abnormalities. (cntraveler.com)
A powerful offshore earthquake shook northeastern Japan on April 20, sending tsunami warnings and evacuation orders along the Pacific coast before alerts were eased later that night. (apnews.com) Japan’s Meteorological Agency said the quake hit at 4:53 p.m. near Iwate Prefecture, and U.S. Geological Survey data put it at magnitude 7.4 off Miyako. Japanese officials initially issued a tsunami warning for Hokkaido, Aomori and Iwate, with advisories extending to Miyagi and Fukushima. (earthquake.usgs.gov (channelnewsasia.com)) The first forecasts warned of waves up to 3 meters, but reported waves were smaller, reaching 80 centimeters at some ports before the warning was downgraded and then canceled. Reuters reported no immediate widespread damage or casualties as the alerts were lifted. (cnbc.com (usnews.com)) A tsunami is a series of long sea waves pushed by sudden movement of the seafloor, and even waves under a meter can flood harbors, sweep away cars, and pull people into the water. That is why Japanese authorities told residents to leave beaches, river mouths and low-lying coastal roads even after the biggest forecasts were cut back. (jp.usembassy.gov (abcnews.go.com)) The quake also triggered a separate “subsequent earthquake advisory,” a notice that the chance of another large quake in the offshore Hokkaido-Sanriku zone was temporarily higher than usual for about a week. Prime Minister Sanae Takaichi’s government set up an emergency task force as officials monitored aftershocks and coastal conditions. (apnews.com (huffpost.com)) That advisory drew attention because the Sanriku coast has a long record of deadly tsunami earthquakes, including the March 11, 2011 disaster that killed more than 22,000 people and set off the Fukushima nuclear crisis. Monday’s quake was much smaller, but it hit the same broad northeastern coastline where tsunami warnings carry unusual weight. (apnews.com (nytimes.com)) Japan’s Nuclear Regulation Authority said nuclear plants and related facilities in the region showed no abnormalities after the quake. The U.S. Embassy in Japan told Americans to keep checking the Japan Meteorological Agency, local authorities and other official channels because tsunami advisories can be upgraded, downgraded or canceled as conditions change. (newsmax.com (jp.usembassy.gov)) By April 21, the immediate tsunami threat had passed, but the official message had not changed: stay alert for aftershocks, and treat every coastal warning as urgent until authorities say it is over. (cntraveler.com (jp.usembassy.gov))
