A magnitude 7.5 earthquake shook the northeastern coast of Japan this Monday, as reported by the country’s Meteorological Agency. The earthquake, recorded at 4:52 p.m. local time (9:52 a.m. in mainland Spain), has generated a tsunami in the prefecture of Iwate and on the island of Hokaido, according to the alert system of Japanese public television NHK. The authorities have observed waves almost one meter high and warn that they could reach three meters.
The epicenter of the tremor was located in the Pacific Ocean and had a depth of ten kilometers, according to authorities, who have urged residents to stay away from coastal areas. It reached a magnitude of 5 on Japan’s seismic intensity scale (which measures the shaking perceived by the population), strong enough to make it difficult for people to move around.
7.5 magnitude earthquake in Japan
Several witnesses have reported collapses of unreinforced concrete walls. The Aomori bullet train, on the northern tip of Japan’s main island of Honshuha, has suspended operations, according to the Kyodo agency. Several port cities, including Otsuchi and Kamaishi, both severely affected by the historic 2011 tsunami, have issued evacuation orders for thousands of residents.
In statements to the press, Prime Minister Sanae Takaichi announced that the Government has created an emergency task force, and has asked citizens of the affected areas. “Possible damage and victims are being investigated,” he said. The NHK network has suspended its programming for the day and broadcasts images from cameras installed in the affected areas and maps with large coastal areas marked in red and the label “Tsunami, Evacuate!”, in Japanese and English. The presenters read the list of municipalities where sea level rises are detected.
“It may take several hours until the maximum wave arrives. It is possible that in some places the tsunami reaches a height greater than that observed at the control stations,” explains the broadcast, which has a calm tone following the public channel’s regulations of warning without instilling panic.
The instructions warn that the tsunami can rise up the slopes and continue inland through rivers or canals.
The Ring of Fire
Japan is one of the countries with the highest seismic activity in the world: it registers at least one tremor every five minutes. Located in the so-called Ring of Fire of volcanoes and oceanic trenches that partially surround the Pacific basin – the area where most of the planet’s active volcanoes are located – the country concentrates 20% of the world’s earthquakes of magnitude 6 or higher, Reuters reports.
As a consequence of this powerful seismic activity, Japan also has one of the most advanced earthquake and tsunami warning systems in the world. It is designed to quickly detect the first seismic waves and anticipate the arrival of stronger waves seconds in advance. It is distributed throughout the country.
The largest earthquake that the archipelago has suffered since records began was the one that occurred on March 11, 2011, which reached a magnitude of 9, causing a gigantic tsunami with waves eight meters high—and, in some inland areas, up to 40 meters—and causing an accident at the Fukushima nuclear power plant. More than 10,000 people died.
There are currently no operating nuclear power plants in the Hokaido and Tohoku regions, but Hokkaido Electric Power Co. and Tohoku Electric Power Co. have several decommissioned nuclear power plants in the area. Tohoku Electric has said it is assessing the impact of the earthquake and tsunami on its Onagawa plant.
