Authorities issued a tsunami alert for the northeast coast Friday after a powerful 7.3-magnitude undersea earthquake struck, setting buildings in Tokyo swaying violently. The warning was lifted at around 7:20 p.m.
They said tsunami up to 1 meter high could sweep ashore in areas badly hit by the March 2011 tsunami that devastated a large swath of the Tohoku region coast, killing thousands.
The Meteorological Agency said the 5:18 p.m. quake was likely an aftershock of the magnitude-9 quake that devastated the region on March 11, 2011, and warned of an aftershock from Friday’s temblor of up to magnitude 6 within a week.
Following the alert, low tsunami reached the coast of Miyagi, Iwate and Fukushima prefectures, according to the agency.
A 1-meter wave was seen in the Ayukawa district in Ishinomaki, Miyagi Prefecture, shortly past 6 p.m., NHK said. In addition, a 20-cm wave was logged by a tsunami gauge off Kinkazan in Miyagi.
Residents in municipalities along the Sanriku coast were advised to evacuate to higher ground.
Those include Rikuzentakata, Ofunato, Yamada in Iwate Prefecture, as well as Miyagino and Wabayashi wards in Sendai and Ishinomaki and Iwanuma in Miyagi Prefecture.
Although the tsunami apparently caused no major damage, the earthquake left at least 10 people injured in six prefectures in the Tohoku and Kanto regions, including Ibaraki, Tochigi and Chiba, the National Police Agency said.
The Aomori Prefectural Government said around 220 households in the town of Gonohe suffered a power outage following the quake.
Telephone operator NTT said the network in the areas was jammed with the weight of calls.
A presenter on NHK repeatedly told viewers to get to safety.
“Remember last year’s quake and tsunami,” he said. “Call on your neighbors and flee to higher ground now!”
The focus of the quake was 240 km off the Pacific coast of Miyagi Prefecture at a depth of 10 km, the Meteorological Agency said.
There was no threat of a Pacific-wide tsunami, U.S. monitors based in Hawaii said. Officials in both Indonesia and the Philippines said there was no threat of a localized tsunami.
Tokyo Electric Power Co. said there were no reports of any problems at its crippled Fukushima No. 1 nuclear plant.
“No abnormalities have been recorded on instruments at the Fukushima No. 1 nuclear plant’s six reactors,” a Tepco spokesman said. “All workers were ordered to take shelter inside buildings at the Fukushima plant.
“No abnormalities were confirmed with the radiation monitoring posts at the Fukushima plant. No abnormalities were seen with the water processing facilities.”
Prime Minister Yoshihiko Noda rushed to his office to monitor the situation, Jiji Press reported.
East Japan Railway Co. temporarily suspended bullet train services on the Tohoku, Joetsu and Nagano shinkansen lines to check for damage.
The Tokaido Shinkansen Line briefly suspended services between Tokyo and Odawara, Central Japan Railway Co. (JR Tokai) said.
Sendai airport near the Miyagi shore grounded all flights, while Narita airport near Tokyo briefly closed its runways. Haneda Airport in Tokyo operated normally.