Stay Alert for Strong Aftershocks, Review Preparedness Measures

In the middle of an extended holiday period, the Noto area of Ishikawa Prefecture was hit by a powerful earthquake registering upper 6 on the Japanese seismic intensity scale of 7. With the possibility of strong aftershocks, local people need to remain vigilant.

The earthquake, centered in the Noto area, occurred shortly after 2:40 p.m. on Friday. With a magnitude of 6.5 at a depth of 12 kilometers, the quake registered upper 6 in Suzu, Ishikawa Prefecture, while recording upper 5 in the town of Noto and lower 5 in Wajima, both in the prefecture.

In Suzu, there have been reports of casualties, including one man who fell from a ladder and other people who were trapped under collapsed buildings or got injured after losing their balance. It is hoped that the central and local governments will swiftly assess the damage and do their utmost to rescue victims.

In the Noto area, relatively moderate earthquakes had occurred frequently since late 2020. In June last year, earthquakes registering lower 6 and upper 5 occurred on two consecutive days in Suzu, prompting the Japan Meteorological Agency to call for people to be on the alert.

The movement of underground water and magma is believed to be the cause, but the connection between Friday’s strong earthquake and these previous frequent quakes is not yet specifically known, the agency said.

The agency said that earthquakes of a similar intensity could occur for a week or so. If such quakes occur in coastal areas, they could trigger tsunami. Local residents should check evacuation routes and locations where they can take refuge.

Rainfall is expected in the Noto area. Ground loosened by the tremors may collapse due to aftershocks and rain. It is important to stay away from hillsides and other risky places.

Local residents should choose a place to sleep where furniture and cupboards will not topple on them in the event of an earthquake. They also need to be careful of objects likely to fall.

Many travelers may have been forced to change their plans due to the earthquake, which occurred during a major holiday period. Transportation systems were affected, with some Shinkansen bullet train services suspended.

The number of foreign tourists visiting Japan is increasing as border-control measures against COVID-19 have been lifted. Some foreign visitors must have been surprised by the sudden quake.

It is crucial for the central and local governments to accelerate efforts to disseminate information and implement measures against disasters for tourists, including foreign visitors.

Following Friday’s earthquake, the agency issued its first earthquake early alert concerning long-period ground motion. When long-period ground motion occurs, large and slow horizontal shaking will continue for a long period of time on the upper floors of high-rise condominiums and other tall buildings.

In urban areas, this is considered an issue in the event of a major earthquake, but it is hard to say that the risk is widely known. It is hoped that this occasion of issuing such an alert will motivate those who work in high-rise buildings or live on upper floors to keep in mind the need to make preparations for long-period ground motion as well.

(From The Yomiuri Shimbun, May 6, 2023)