Japan Revises Nankai Trough Megaquake Probability

Tokyo, Sept. 26 (Jiji Press)–A Japanese government panel said Friday it now thinks that a huge earthquake will occur along the Nankai Trough with a probability of 60 pct to 94.5 pct or higher within the next 30 years. In its report issued the same day, the Earthquake Research Committee widened the probability range for an 8- to 9-magnitude earthquake occurring off the country’s Pacific coast from “around 80 pct” it announced previously, due to some unreliabilities in the past ground uplift data from Muroto Port in the western prefecture of Kochi and nonconstant plate strain accumulation. “An actual earthquake is an unpredictable natural phenomenon,” Naoshi Hirata, honorary professor at the University of Tokyo and head of the panel, said. “We can’t clearly say when it will happen. It may be more than 30 years away but may come within a year.” Maga earthquakes have occurred along the Nankai Trough once every 90 to 150 years. The last one, with an estimated magnitude of 8.0, happened in 1946. The long-term earthquake risk assessment report also showed a separately calculated 20-50 pct probability range. Although it cannot be scientifically determined which assessment is superior, the panel said, “the higher chances of a Nankai Trough quake should be highlighted” to raise local residents’ awareness of an imminent disaster. In March, the government said in its new estimate that if a 9-magnitude earthquake occurs along the trough, up to around 298,000 people would die and the country’s economic loss would amount to 292 trillion yen. END [Copyright The Jiji Press, Ltd.]