TEMPO.CO, Jakarta - Authorities have warned residents in northeastern Japan to prepare for a potentially larger earthquake following the 7.7-magnitude earthquake that hit off the coast of Iwate on Monday, which triggered a tsunami in the region, as reported by The Japan Times.
The current warning will remain in effect until April 27 at 17:00 local time.
Cabinet Secretary Minoru Kihara, the government's chief spokesman, stated in a Monday evening press conference that the government has established a crisis management center.
"We are making every effort to assess the situation and carry out emergency disaster response measures, including search-and-rescue operations," he said. He added that power outages have been reported in around 100 households in Aomori Prefecture so far.
Speaking to reporters in Tokyo, Prime Minister Sanae Takaichi urged residents to continue their daily activities but remain prepared for evacuation at any time.
"It is particularly important in coastal areas to evacuate immediately if you feel tremors or if a tsunami warning is issued," she said.
Residents in areas under special warning - for 182 municipalities from Hokkaido to Chiba Prefecture - have been urged to stay vigilant and prepared to evacuate at any time, according to officials from the Japan Meteorological Agency (JMA) and the Cabinet Office in a joint press conference on Monday evening.
Residents have been urged to confirm their evacuation plans, including evacuation routes and communication methods with family.
Although the likelihood of a powerful earthquake with a magnitude of 8 or higher is greater than usual, at about 1 percent, or 10 times higher than the 0.1 percent during normal times, said the JMA.
If a major earthquake occurs, an accompanying tsunami is also expected. Smaller earthquakes in the region may also occur.
The last special warning was announced in December, following a 7.5-magnitude earthquake off the east coast of Aomori Prefecture.
The JMA has had a system in place since 2022, where if a 7-magnitude earthquake strikes off the coast of Iwate and Hokkaido, they will consider issuing a warning for a potential stronger earthquake - referred to as a "subsequent quake advisory" - given past similar occurrences.
Earthquake in Iwate
Monday's earthquake, which occurred at a depth of 20 kilometers about 100 kilometers off the coast of Iwate Prefecture at 16:52, registered a magnitude of 5 on the Japanese seismic scale up to 7 in some parts of Aomori, Iwate, and Miyagi prefectures, according to JMA.
The earthquake struck off the northeastern coast of Sanriku, Japan, and 530 kilometers from the country's capital, Tokyo, with an epicenter in the Pacific Ocean.
Tokyo and its surrounding areas - where buildings shook for several minutes - recorded a 3 on the Japanese scale.
Two people sustained minor injuries from the earthquake - an elderly man in his 80s in Morioka, Iwate Prefecture, and a woman in her 20s in Tohoku, Aomori Prefecture, reported NHK. Twenty-six non-residential buildings, including schools and restaurants, were damaged in Aomori, the prefectural government said.
The earthquake triggered a 80-centimeter tsunami at Kuji Port in Iwate Prefecture, while Miyako Port, also in Iwate, experienced a 40 cm tsunami. Waves are also expected to reach other locations along the extensive coastline of the prefecture.
In Hokkaido, the town of Urakawa experienced a 40 cm tsunami. Hachinohe Port in Aomori recorded a 30 cm tsunami, while the city of Erimo and Ayukawa Port in Miyagi Prefecture experienced a 20 cm tsunami.
Some JR Hokkaido trains in affected areas were canceled, but trains operated normally in the Sapporo area, including between Sapporo and New Chitose Airport.
Throughout Hokkaido and the prefectures of Iwate, Aomori, Miyagi, and Fukushima, evacuation orders were issued for nearly 172,000 people, reported NHK, citing the Ministry of Internal Affairs. Over 156,000 people were reported to have been evacuated in five prefectures along the country's coastline.
The earthquake initially triggered a tsunami warning, where waves were estimated to reach up to 3 meters. The warning was lifted on Monday evening.
The earthquake and its accompanying tsunami warnings prompted TV news program hosts to urge residents to move to higher ground, away from rivers and coastlines, calling on people to "remember the 3/11 disaster."
"Tsunami! Evacuate!" appeared on NHK in English. "Don't turn back."
The warnings and notifications serve as a clear reminder of the Great East Japan Earthquake and tsunami on March 11, 2011, which struck the area, resulting in almost 20,000 deaths and forcing around 125,000 people to evacuate.
Following a 6.9-magnitude earthquake that also struck off the Sanriku coast in 2015, a 6.5-magnitude earthquake hit three days later and another 6.4-magnitude earthquake occurred after five days.
Secondary impacts, such as landslides, are also a concern for the coming days, with rain expected on Tuesday, April 21, 2026, in Hokkaido and Aomori.
Japan Maritime Self-Defense Force SH-60K helicopters flew over the Sanriku coast in the Tohoku region to gather information and assess damage, MSDF said.
No anomalies were reported at the damaged Fukushima No. 1 and No. 2 nuclear power plants in Fukushima Prefecture or the Onagawa nuclear power plant in Miyagi Prefecture, said Tokyo Electric Power Company Holdings.
JMA also stated that it had observed a level 3 earthquake called a long-period earthquake - or seismic waves with different durations that last longer - in Akita Prefecture.
Read: Tsunami Threat Eases After Powerful 7.7 Earthquake in Japan
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