Arab News Japan

TOKYO: A strong earthquake rocked eastern and northeastern Japan on Tuesday morning, measuring lower five on the Japanese seismic intensity scale in Ibaraki Prefecture, the Japan Meteorological Agency and local media reported.

The eyewitness said that the quake caused Tokyo buildings, especially the high-rise floors, to shake mildly for more than 15 seconds.

The 8:16 a.m. quake epicenter had an estimated magnitude of 5.4 at a depth of 93 kilometers in Fukushima Prefecture, Ibaraki’s northern neighbor, the agency said. The level of lower 5, recorded in the northern Ibaraki town of Shirosato, is the fifth-highest on the scale.

According to local reports, the earthquake caused a suspension and delays of trains in the region. The Nuclear Regulation Authority said no abnormalities were reported in the nuclear plants in the area, including Tokai and Fukushima reactors.

Experts said the epicenter is located deep inland on the border between Fukushima and Ibaraki prefectures, but it is not a typical inland earthquake (shallow crustal earthquake). A normal inland earthquake occurs at a depth of about 20 km or less, but this time the epicenter is as deep as 90 km, and it seems that the earthquake occurred at the top of the subducted Pacific plate. It was the same type of earthquake off Fukushima prefecture on February and March 16.

Local authorities in areas with strong shaking advised residents to be careful of earthquakes with a maximum seismic intensity of less than 5 for about a week after the occurrence of the earthquake. In particular, large-scale earthquakes often occur in the next few days. 

According to the preliminary analysis of the Japan Meteorological Agency, the mechanism of this earthquake seems to be a strike-slip fault type with a tension axis in the north-northwest-south-southeast. Due to the deep epicenter and relatively large scale, moderate tremors probably reached a wide area.

*With JIJI Press