The Japan panel of experts says that any tsunami unleashed by a magnitude-9.0 earthquake in the Nankai trough, which runs east of Japan’s main island of Honshu to the southern island of Kyushu, could top 34 meters at its highest, reports MSNBC.
An earlier forecast of 2003 estimated the potential maximum height of such a tsunami at less than 20 meters (66 feet).
The projections, posted on a government website, are based on new research following last March’s magnitude-9.0 earthquake and tsunami, which devastated a long stretch of Japan’s northeastern coast and killed about 19,000 people.
Last March’s magnitude-9.0 earthquake spawned a 14-meter (45-foot) wave that devastated most of Japan’s northeastern coast and triggered meltdowns at a nuclear power plant, says Newser.
The catastrophe, and the crisis at the Fukushima Dai-ichi nuclear power plant, has prompted sweeping reviews of Japan’s disaster preparedness, and criticism over apparent failures to take into account potential risks.
The tsunami knocked out power at the 40-year-old coastal nuclear plant and led to the worst nuclear disaster since Chernobyl in 1986.
Tens of thousands of residents have had to leave the area, and it’s unclear whether some will ever be able to move back.
Yahoo! informs that the report, issued Friday by the Ministry of Education, came in the form of mapping that shows that much of the Tokyo region would likely experience severe shaking from a magnitude-7.3 earthquake inside Tokyo Bay.
The report shows that a strong earthquake hitting the Tokyo Bay region could shake the Tokyo-Yokohama metropolitan area — home to more than 33 million people — at the maximum seismic intensity of 7 on the Japanese scale.
The report prompted Tokyo residents to be better prepared for such disasters. Although they live with the constant threat of a major earthquake, not all living in the region keep recommended water and other supplies on hand.
The revised tsunami forecast for a possible Nankai earthquake says Tokyo could expect waves up to 2.3 meters (7.6 feet) high. But at the coastal town of Kuroshio, on the island of Shikoku, the tsunami could top 34 meters (112 feet), it shows.
Moreover, the latest forecast shows a tsunami of up to 21 meters (69 feet) could strike near the Hamaoka nuclear plant.
Its operator, Chubu Electric Power Co., is currently building an 18-meter (59-foot) high sea wall to counter tsunamis. The wall is due to be completed next year.
The plant was shut down in 2011 due to estimates it has a 90 percent chance of being hit by a magnitude 8.0 or higher quake within 30 years.
The Fukushima plant was designed to withstand a 20-foot (6-meter) tsunami, less than half the height of the surge that hit it on March 11, 2011.
The newspaper Asahi Shimbun listed troubles that might be expected from a major quake, such as electricity outages that could persist for more than a week and water supply disruptions that could last for nearly a month, according to government estimates.
The computer modeling for the revised forecasts assumes a high tide for the highest estimates.