An earthquake centered in western Shizuoka Prefecture shook Aichi Prefecture with a maximum intensity of 5-strong in the early hours of the 8th, and a Nagoya University professor says residents should treat it as a prompt to prepare for a larger quake rather than as a Nankai Trough event.
The quake had a magnitude of 5.7. The strongest shaking was recorded in Chita, Aichi Prefecture, some distance from the epicenter. Nobuo Fukkawa, an emeritus professor at Nagoya University, told Tokai TV that Aichi had not felt shaking of that strength for about 30 years.
Why Chita shook hardest
Fukkawa said the quake was relatively deep and not especially large. In a quake that rattles rather than sways, he said, ground with good soil conditions can shake more easily. Looking at the distribution of shaking, he said, many of the places that shook hardest had good ground.
Not a Nankai Trough quake
Asked about any link to the Nankai Trough earthquake — the long-anticipated megaquake along the boundary between two tectonic plates off Japan's Pacific coast — Fukkawa said the impact would not be great. The quake did not occur at the plate boundary but inside the subducting plate, so it is not directly a boundary quake. At magnitude 5.7 it is not large enough to trigger a truly major earthquake, he said.
The warning that still applies
Fukkawa said a larger earthquake could still occur and that people should stay alert. Shaking of this kind, he said, is a chance to take countermeasures.
“If you can, I would like you to check your home today.”Nobuo Fukkawa, Emeritus professor, Nagoya University
At least five people were injured in the quake by 3 a.m. on the 8th, including one person struck in the face by a falling object, according to reports. Central Japan Railway warned that some conventional JR lines in the Tokai region could suspend service from the first trains, and Tokaido Shinkansen services were expected to be delayed from the first departures.