Cities in northern Japan struggle to prepare for a mega-earthquake

From long distances to evacuation sites to lack of proper shelter structures and warm clothing, municipalities in Hokkaido and the Tohoku region are struggling to prepare for a tsunami caused by a mega-earthquake. in an ocean trench.

Faced with harsh climates, geographical challenges and stretched budgets, this task is proving difficult for many local governments.

The central government predicts that a 9.1 magnitude mega-earthquake would cause up to 199,000 deaths if it struck late at night in winter in the Japan Trench, part of the Pacific Ring of Fire in north- east of Japan.

It also predicts up to 100,000 deaths in the event of a magnitude 9.3 mega-earthquake hitting the Chishima Trench, which lies off Tokachi in Hokkaido and extends to the Kuril Islands.

In the town of Erimo, at the southern end of the Hidaka mountain range in central Hokkaido, houses line the seven fishing ports of Cape Erimo which faces the Pacific Ocean.

The Hokkaido government estimates that a tsunami of up to 26 meters could sweep through the region about half an hour after a mega-quake hit the Chishima Trench.

Most of Erimo’s homes are in areas likely to be flooded by such a tsunami, but the town has no facilities for residents to seek shelter from such a disaster.

Erimo conducted an evacuation drill in the late afternoon of March 2 in a scenario based on an earthquake hitting the area in the early hours of mid-winter.

In the Erimo-Misaki neighborhood, elderly residents rode separately in 70 cars as they evacuated to a parking lot 55 meters above sea level. It took about 20 minutes to get them to safety.

But the head of a residents’ association warned that some may not be able to get there within half an hour if an earthquake hits the area late at night, as they would need more time to prepare.

During the exercise, many residents did not bring anything to warm up. Each district is stocking stoves, blankets and makeshift beds at local evacuation centers. But they can only cover about 30% of Erimo’s population. The city stocks up on these items every year, but can only spend 2 million yen ($16,520).

Erimo Mayor Masaki Onishi, 68, expressed concern that National Highway No. 336, which runs along the east and west coasts of Cape Erimo, could be cut off during a tsunami. If this happened, people injured in the disaster could not be transported to major hospitals because the road is the only highway connecting the city and its neighboring municipalities.

Onishi said he has been asking the central and Hokkaido governments to build a bypass road for five years, but no progress has been made.

In Sendai, the capital of Miyagi prefecture, more than 100 people took shelter in coastal evacuation towers and other structures after the March 16 earthquake.

The city constructed evacuation towers and buildings at 11 locations on the Pacific coast after the Greater East Japan earthquake and tsunami. To protect against the cold, the city stores blankets and stoves in these structures and builds walls in the escape towers that can protect people from the wind.

In Iwate Prefecture, the death toll from a mega-earthquake in an ocean trench could surpass that of the 2011 disaster and reach 11,000 in a worst-case scenario. The prefecture has only one evacuation tower in Kuji because construction costs are high and there are many higher areas to which people in urban areas can easily evacuate.


In its report on disaster preparedness measures in the event of a mega-earthquake in the ocean trenches, a task force of the Central Council for Disaster Prevention recommended the construction of towers and buildings where people could stand shelter from an ensuing tsunami.

According to Cabinet Office data, 15,806 of these structures were built across the country in April 2021.

But about 85% of them are in areas expected to be hit by a mega-earthquake along the Nankai Trough off the Pacific coast. Coastal municipalities in Hokkaido and four Tohoku prefectures near the focus of a mega-earthquake in the Japan Trench or Chishima Trench constructed 743 towers and evacuation buildings, less than 5 percent of the national total.

Municipalities can designate large coastal public facilities as evacuation buildings and construct new evacuation towers if such facilities do not exist.

Hamanaka, Hokkaido, plans to build towers. But a city official said the project would place a huge financial burden on the municipality, given that the central government pays only half of the costs incurred to build the towers.

The government is expected to raise that figure to two-thirds as it revises a special law enacted in 2004 to prepare the public for a mega-earthquake in an ocean trench.

But even that worries municipalities.

“Bearing a third of the cost is always a huge burden for a city with few financial resources,” said an official from another coastal city in Hokkaido. “If we take measures against the cold, the cost increases further. We ask for full (financial) support.