Widely felt quake occurred within Pacific Plate

Measuring a maximum of upper 6 on the Japanese seismic intensity scale, the quake was a different type from the Great East Japan Earthquake, which occurred at the boundary of the oceanic Pacific Plate and a continental plate. The Pacific Plate subducts under a continental plate.

Strong tremors were felt over a wide area on Wednesday night, including Fukushima and Miyagi prefectures.

“There have been many earthquakes inside a plate that had a deep focus, and in which seismic tremors were felt widely, because they’re easily transmitted far through the plate,” said Prof. Takashi Furumura of the University of Tokyo’s Earthquake Research Institute.

“This time, the quake involved shaking with a cycle of about one second, which tends to cause damage to wooden houses, and slighter, more frequent tremors that are likely to cause disasters such as landslides. The quake also lasted for a long period of time,” Furumura said. “This may have led to such damage as the collapse of houses.”

However, long-period tremors, which tend to shake high-rise buildings, were also observed in many areas.