TOKYO — Authorities in Japan issued a special earthquake advisory on April 20 following a powerful offshore tremor that struck the country’s northeast and briefly triggered tsunami warnings.
According to the Japan Meteorological Agency, the earthquake, initially measured at magnitude 7.4 and later upgraded to 7.7, occurred at 4:53 p.m. local time in Pacific waters off Iwate Prefecture. The quake was strong enough to sway buildings in Tokyo, located hundreds of kilometers from the epicenter.
In an advisory issued hours later, the agency warned that “the likelihood of a new, huge earthquake occurring is relatively higher than during normal times,” while clarifying that the notice reflects elevated risk rather than a specific prediction.
Local governments in affected areas issued non-mandatory evacuation advisories to more than 182,000 residents, according to the Fire and Disaster Management Agency. About 40 minutes after the quake, an 80-centimeter tsunami wave was recorded at a port in Kuji, also in Iwate.
By late evening, tsunami warnings for waves of up to one meter were downgraded to advisories across parts of northeastern Japan, including Hokkaido, Aomori Prefecture, Iwate, and Fukushima Prefecture. These advisories were fully lifted around midnight, according to Kyodo News.
Chief Cabinet Secretary Minoru Kihara said there were no immediate reports of serious injuries or significant damage. Initial footage from NHK showed no visible destruction in several coastal areas, though officials cautioned that aftershocks could continue over the coming week, particularly within the next two to three days.
The International Atomic Energy Agency reported no abnormalities at nuclear facilities. Utility operators, including Tohoku Electric Power, said they were conducting inspections, including at the Onagawa nuclear plant. No nuclear plants are currently operational in the Hokkaido and Tohoku regions.
Prime Minister Sanae Takaichi said a crisis management team had been activated to assess potential damage and coordinate response efforts. “For those of you who live in areas for which the warnings have been issued, please evacuate to higher, safer places,” she said.
Transport services were also disrupted, with bullet train operations in Aomori temporarily suspended due to the tremors.
As of April 21, authorities have reported a series of minor aftershocks in the affected region, but no escalation to a major event. Infrastructure inspections are ongoing, and transport services have largely resumed. Officials continue to urge residents to remain vigilant and review emergency preparedness measures.
Japan remains one of the most seismically active countries in the world, located along the Pacific “Ring of Fire,” where several tectonic plates converge. The country experiences around 1,500 earthquakes annually, accounting for roughly 18 percent of global seismic activity.
Memories of the 2011 Tōhoku earthquake and tsunami, which killed or left missing about 18,500 people and triggered the Fukushima nuclear crisis, continue to shape disaster preparedness policies.
Authorities have also previously warned of the potential for a major earthquake along the Nankai Trough, a zone capable of generating a devastating quake and tsunami. Government estimates suggest such an event could result in up to 298,000 deaths and economic losses reaching $2 trillion.
Officials reiterated that while the probability of a larger quake remains low, heightened caution is necessary in the days following a major seismic event.
Paraluman P. Funtanilla
Paraluman P. Funtanilla is Tutubi News Magazine's Marketing Specialist and is a Contributing Editor. She finished her degree in Communication Arts in De La Salle Lipa. She has worked as a Digital Marketer for start-up businesses and small business spaces for the past two years. She has earned certificates from Coursera on Brand Management: Aligning Business Brand and Behavior and Viral Marketing and How to Craft Contagious Content. She also worked with Asia Express Romania TV Show.
- Paraluman P. Funtanilla
- Paraluman P. Funtanilla
- Paraluman P. Funtanilla
- Paraluman P. Funtanilla
