Image Credits: Kyodo News
In response to heightened seismic activity and a recent warning from the Japan Meteorological Agency (JMA), Japanese authorities are urging residents in the Nankai Trough area to prepare for a possible major earthquake. The call for preparedness follows the issuance of a “Megathrust Earthquake Attention” alert on Thursday, which was prompted by a significant magnitude 7.1 earthquake that struck southern Miyazaki Prefecture earlier in the day.
This alert, marking the JMA’s inaugural issuance of such a warning, reflects an increased likelihood of a devastating megaquake in the Nankai Trough region. Naoshi Hirata, professor emeritus at the University of Tokyo and chair of the Nankai Trough Earthquake Assessment Committee, emphasized the heightened risk, stating that the probability of a major quake occurring has risen substantially. Hirata’s comments, made during a press conference, highlighted the need for vigilance despite the warning’s current status.
Historically, strong earthquakes of magnitude 7 or higher have been recorded 1,437 times globally from 1904 to 2014, with a notable incidence of large quakes occurring within a short time frame following initial seismic events. For instance, a magnitude 7.3 quake preceded the magnitude 9 Great East Japan Earthquake in 2011. While the JMA’s analysis suggests a one-in-several-hundred chance of a magnitude 8 or greater quake, the current risk is deemed elevated.
The warning system, established in May 2019, is designed to alert residents following significant seismic activity in the Nankai Trough area. If a magnitude 6.8 or higher quake or a slow slip event occurs, the JMA is set to issue a formal announcement. The recent magnitude 7.1 quake, occurring in the critical Hyuganada Sea area, prompted an immediate response from the JMA, culminating in the issuance of the Megathrust Earthquake Attention.
Seismologist Shoichi Yoshioka from Kobe University noted that while the recent quake was smaller than what would typically trigger a megaquake, it nonetheless increases the potential for a larger event in the Nankai Trough.
Authorities stress that residents in the affected area should not evacuate immediately but should prepare for the possibility of strong earthquakes over the coming week. This preparation includes ensuring family members’ locations are known and having emergency supplies readily accessible. Should a magnitude 8 or greater quake occur, a “Megathrust Earthquake Alert” will be issued, prompting immediate evacuation procedures, particularly for vulnerable individuals and non-Japanese speakers.
In light of the warning, disaster preparedness experts like Nobuo Fukuwa, professor emeritus at Nagoya University, advise against panic buying or hoarding supplies. Fukuwa cautions that misinformation and unverified earthquake forecasts may circulate on social media, urging the public to rely solely on official updates from the JMA and local government authorities.
The call for calm and preparedness reflects Japan’s ongoing commitment to managing and mitigating the risks associated with its seismic activity, ensuring that the public remains informed and ready for potential emergencies.