Japan's megaquake alert ends amid no major new seismic activity

TOKYO (Kyodo) -- A weeklong government call for increased preparedness based on an advisory over a potential megaquake along the Pacific coast officially ended 5 p.m. Thursday, after no new major seismic activity was confirmed around the Nankai Trough.

The Nankai Trough megaquake advisory, the first since the system was implemented in 2017, prompted the central government and local communities to intensify disaster preparations over the past week. It also negatively impacted some tourism-related businesses during the summer holiday season.

Japan, a quake-prone nation, has long feared a quake of magnitude 8 to 9 along the Nankai Trough within the next 30 years, with predictions that a wide area could be jolted and vast coastal regions engulfed by massive tsunami.

The megaquake advisory was issued just hours after a magnitude-7.1 quake rocked southwestern Japan on Aug. 8, with its focus located in waters off Miyazaki prefecture, on the western edge of the Nankai Trough.

The advisory is intended to inform the public of the higher-than-usual risk of a large-scale quake around the Nankai Trough for a week. The government is urging the public to remain vigilant and prepared, as the possibility of a major temblor has not been eliminated.

The Nankai Trough is an ocean-floor trench that runs along Japan's Pacific coast where the Eurasian and Philippine Sea tectonic plates meet.

The Japan Meteorological Agency stated that as of Wednesday, it had detected no seismic activity indicating any concerning changes in the presumed area where the megaquake could originate.

According to the Cabinet Office, the advisory has been applied to 707 municipalities across 29 prefectures where strong shaking and large tsunami are expected in the event of a