A large-scale earthquake in the Sea of Japan has the potential to generate a tsunami that could reach as high as 23 meters, a Japanese government commission predicts.
Despite its massive scale, such a tsunami would still pale in comparison to the 38.9 meter tsunami that hit Japan’s northeast coast on March 11, 2011, killing well over 10,000 people and causing widespread destruction throughout the region.
Through investigation and large-scale modeling, the commission, which is under the aegis of the Ministry of Land, Infrastructure, Transport and Tourism, or MLIT, is hoping to mitigate the potential damage that a tsunami off of the west coast of the Japanese archipelago could have. Tsunami predictions in the lead-up to the 2011 disaster were notoriously under-target, resulting in the construction of insufficient flood defenses throughout Japan’s northeast coast.
The commission projected that an earthquake with a magnitude between 6.8 and 7.9 could generate such a tsunami, which would affect the entire Sea of Japan coast from Hokkaido to southern Kyuushuu. That would only be slightly stronger than the 2007 Chuetsu offshore earthquake, which was also located in the Sea of Japan, and well below the 9.0 magnitude of the 2011 Tohoku earthquake.
The commission also estimated the worst of the tsunami would likely hit the country’s northwest coast, where maximum wave heights are projected to hover 12 to 23 meters. In Japan’s south the maximum height will likely taper down to around five to seven meters.
While the tsunami could possibly reach 23.4 meters in the town of Setana on the northern island of Hokkaido, a call from The Wall Street Journal to the ministry confirmed that in flat areas within 200 meters of the coast, the average tsunami height will reach only as high as 10.4 meters.
At Tomari, the location of Hokkaido’s only nuclear power plant, the tsunami could rise to as high as around 5.8 meters, while at the Monju fast breeder reactor and Takahama nuclear power plant in Fukui prefecture, the earthquake-generated tidal wave is estimated to reach 2.7 and 3.3 meters respectively, a representative from MLIT said. At the Kashiwazaki-Kariwa nuclear power plant in Niigata, one of the largest in the world, waves are projected to reach a maximum of 3.5 meters. All four estimates are lower than the almost 15 meter high wave which hit the Fukushima Daiichi plant in March 2011.
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