Two strong earthquakes struck Japan’s central prefecture of Nagano on Saturday afternoon.
The Japan Meteorological Agency says the first one was at 1:20 p.m. and had a magnitude 5.0. It measured a seismic intensity of upper 5 on the Japanese scale of 0 to 7 in the hardest-hit areas. A magnitude 5.1 quake hit the same area at 2:54 p.m.
The second quake’s intensity was lower 5 in the cities of Nagano and Omachi. The agency said the depth was 10 kilometers.
In Omachi, an intensity of upper 5 was observed earlier on the same day.
The agency says there is no threat of tsunami from either quake.
Officials in Omachi say roof tiles were torn off and fell from one house in the city.
There was damage to walls of some other buildings. Gravestones also toppled.
Tokyo Electric Power Company says the No.6 reactor at the Kashiwazaki-Kariwa nuclear plant in neighboring Niigata Prefecture is in operation and no abnormalities have been found so far.
Japan Meteorological Agency official Ebita Ayataka said: “Please be on alert for earthquakes with a maximum intensity of upper 5 for the next week. There have been a series of quakes in this area in the past. As there is a risk of stronger ones, please remain on full alert.”
Officials are also asking people to remain on high alert amid rainy conditions as areas with strong shaking are at risk of falling rocks and landslides.
Saturday’s quakes occurred in areas close to where a magnitude 6.7 earthquake struck in 2014.
An expert says even though it has been over a decade, Saturday’s quakes in a broad sense could be considered as aftershocks of the 2014 event.
Professor Nishimura Takuya of Kyoto University’s Disaster Prevention Research Institute points out that the eastern and western plates meet in Nagano Prefecture. He says this makes the area prone to a buildup of strain.
He adds, “It is possible that a fault zone near the epicenter could slip someday and cause large quakes.” He urged people there to stay on alert.
AloJapan.com