Photo/IllutrationA house tilts in Sapporo's Kiyota Ward after a powerful earthquake on Sept. 6. (Reina Kitamura/ The Asahi Shimbun)

A strong earthquake struck Hokkaido in the early hours of Sept. 6, leaving dozens of people dead or missing and causing serious damage to infrastructure.

As rescuers grasp the scale of the damage and work to save lives, the magnitude-6.7 quake, whose epicenter was in the Iburi district in southern Hokkaido, reminded us again of the Japanese archipelago’s vulnerability to seismic activity.

The temblor triggered landslides in wide areas. The search for missing people, the top priority, is being carried out in the town of Atsuma, where the intensity of the quake reached the maximum intensity of 7 on the Japanese seismic scale and many houses collapsed.

In Sapporo, the capital of the northern main island, soil liquefaction cause road subsidence. The number of injured people continues to increase.

The Japan Meteorological Agency (JMA) has warned that strong aftershocks that could measure as high as an upper 6 could hit the affected areas during the next week or so.

At homes, schools, workplaces and other facilities, effective preparations should be made for such aftershocks.

It is important to assess the damage to the buildings and ensure swift evacuations in case the ground starts shaking again.

Substantial rainfalls forecast for the affected region on the night of Sept. 7 could trigger additional landslides. It is vital to avoid dangerous areas, such as places close to mountains.

Also worrisome are the cuts in power and water supplies that have affected far wider areas than expected.

The entire island was without electricity for long hours. It is extremely rare for a whole region to be without power supplied by a major utility.

Hokkaido Electric Power Co. says a chain reaction caused the total power cut.

A coal-fired thermal plant in Atsuma, the largest in Hokkaido and responsible for half of the overall power supply to the island, was heavily damaged in the earthquake. The suspension of operations at the plant caused an imbalance in the supply and demand for electricity, forcing operations to be stopped at all other thermal plants in Hokkaido, according to the utility.

The large-scale power failure has exposed the weak underbelly of the highly centralized power supply system.

It will take at least a week to fully restore the power supply, the utility says.

In addition to affecting people’s daily lives, the prolonged power outage will also cause a wide range of disruptions, from the suspension of railway and airline services to the failure of city traffic lights. Disruptions to transportation networks will directly lead to failures in distribution systems.

Hokkaido Electric Power should spare no effort in restoring power as soon as possible.

Many people have taken refuge at evacuation centers in Sapporo and other areas.

Do these centers have sufficient supplies of drinking water, food and bedclothes for the evacuees? Are the toilets and air-conditioning equipment in good condition?

It is also vital to bring emergency supplies to people who cannot leave their homes and secure electricity supplies to medical institutions.

To ensure adequate and proper emergency aid to quake-hit areas, the central government needs to provide the necessary manpower and emergency supplies to local governments.

As many as 2,000 active faults are confirmed across Japan. Many earthquakes at active faults come unexpectedly because they occur at intervals of 1,000 to several tens of thousands of years.

The Sept. 6 earthquake hit an area of Hokkaido that was considered at a much lower risk for giant quakes than the high-risk areas along the Chishima Trench, including near the city of Nemuro.

The quake sends a clear message that we must remain on guard.

This summer, Japan has been battered by a series of deadly natural disasters, including floods, typhoons and earthquakes.

Earthquakes are especially hazardous because of their unpredictability. Daily efforts to prepare for big quakes can make the difference between life and death.

The disaster in Hokkaido should remind people in other parts of the nation that they are also vulnerable.

--The Asahi Shimbun, Sept. 7