12:30 JST, October 9, 2022
If an earthquake occurs in winter in the coldest regions of northern Japan, affected residents run the risk of freezing to death even if they escape the tsunami. The key to minimizing damage is to have cold weather measures in place at the vent facilities.
In anticipation of a massive earthquake with its epicenter anywhere in the region, from Iwate Prefecture to Hokkaido in the Japan Trench or the Chishima Trench in the Pacific Ocean, the government has designated 272 municipalities in eight prefectures as areas where countermeasures need to be strengthened. Of these, 108 municipalities have been designated as areas where tsunami flood precautions are particularly required.
Last year the government announced its estimate that up to 199,000 people could die if an earthquake of around magnitude 9 occurred “late at night in winter”, when evacuation is slowed due to snow accumulation and other factors. The government said the height of the tsunami is estimated at 30 meters in some areas.
Each of the designated municipalities will formulate their own disaster management plans. Unlike a Nankai Trough earthquake and an epicentral earthquake directly beneath the Tokyo metropolitan area, most areas affected by an earthquake occurring near the Japan Trench or the Chishima Trench are expected to experience very cold weather during the winter. Seismic countermeasures adapted to cold regions are essential.
Tsunami evacuation towers have been built to allow residents to climb to raised floors for shelter in areas where the tsunami is expected to strike. However, the tops of these towers are exposed to the open air and there is not enough cold weather gear available in some towers.
Roofs and walls should be installed to cut wind and snow, with the possibility of overnight stays in the towers in mind. Preparing items such as tents would also be a good idea. Blankets and heating pads should also be stocked.
It is also important to take measures against the cold in the evacuation centers. In addition to fuel oil or wood-burning stoves, emergency foods that can be eaten hot without a fire should be prepared so that people can stay warm even in the event of a power outage.
In Miyako City, Iwate Prefecture, where a major tsunami is feared, residents held a pre-dawn evacuation drill in March. They used flashlights to light their way to higher ground. Everyone should increase their evacuation awareness so that residents can escape quickly, even late at night in winter.
Areas inundated by tsunamis extend beyond municipal boundaries. A system allowing extensive cooperation between neighboring municipalities as well as a flexible supply of supplies and the dispatch of support staff should be developed.
Last month, Typhoon No. 15 caused a large-scale water supply suspension in Shizuoka Prefecture, but it took two days before the prefectural government asked the Self-Defense Forces to send a disaster relief mission. Local governments should coordinate in advance with the SDF and other related agencies so that aid can be received quickly in the event of an earthquake.
The government says the number of expected deaths can be reduced by 80 percent if central and local governments, businesses and residents promote tsunami countermeasures in advance. Earthquakes can happen at any time. Countermeasures must be prepared now.
(From Yomiuri Shimbun, October 9, 2022)