TOKYO — The next major earthquake to hit Japan’s capital would likely kill more than 6,000 people, injure another 93,000 and leave 4.5 million people homeless, according to a government report released Wednesday.
A magnitude 7.3 earthquake with an epicenter in south-central Tokyo would also damage more than 194,000 buildings, according to the first earthquake study by the Tokyo Metropolitan Government in a decade. The report estimates the probability of such an earthquake at 70% within the next 30 years.
The Tokyo area is home to about 12,000 U.S. service members and their families, most living at Yokota Air Base in the western part of the prefecture.
However, a group of experts quoted in the report predicted less damage in the next earthquake than a similar report estimated in 2012. This report predicted more than 9,000 dead, 147,000 injured, 304,000 structures damaged and 5 .2 million people unable to return home.
According to the latest report, more earthquake-resistant houses and fewer wooden houses in dense communities are considered in the new estimate.
“The Tokyo Metropolitan Government has been working to further build resilience…since the Great East Japan Earthquake,” the report said.
The magnitude 9 earthquake that hit Japan in March 2011 created a massive tsunami that flooded the northeast coast, killing more than 19,000 people and causing the Fukushima Daiichi nuclear power plant to collapse.
Since then, the percentage of earthquake-resistant houses in Tokyo has increased from 81.2% to 92%. According to the report, more than nine out of ten buildings along major roads designated for emergency use are now earthquake resistant.
A major earthquake in Tokyo would cause 80,000 buildings to collapse, 40,000 fewer than the 120,000 estimated in the 2012 report.
Fewer wooden houses in dense suburbs means fewer estimated fire deaths after a large earthquake, from 4,100 to 2,500, the report said.
The probability of a magnitude 7.4 earthquake along the Tachikawa Fault, close to where many US service members live and work, is very low, only a 0.5 to 2 percent chance at over the next 30 years, according to the report.
In this case, the cities of Musashimurayama, Akishima, Fussa and Tachikawa would suffer severe tremors, Tokyo Shimbun reported on Wednesday. A major event along this fault would likely kill 1,500 people, injure 19,000 and damage 52,000 structures, according to the metropolitan government report. Another 590,000 people would be forced to evacuate.
This is down from the 2,500 dead, 31,000 injured, 1 million evacuees and 86,000 damaged structures projected in the 2012 study.
Structures built on Yokota after 1981 conform to a Japanese national standard and must remain upright, even during a very large earthquake, said Roland Nishimura, then chief of architecture for the 374th Engineer Squadron, in March 2012 Older buildings can sustain structural damage in such an earthquake, he says.
The base’s residential towers, even the older ones, appear capable of withstanding an earthquake, Nishimura said.
Tokyo residents, including the U.S. military community, need to be prepared, said Naoshi Hirata, director of the Earthquake Prediction Research Center at the University of Tokyo.
“An earthquake, which can occur somewhere in Tokyo, is very strong when observed around the world,” he said by phone on Friday.
Furniture, such as high shelves and cupboards, must be protected against falls and injuries. And the military should stockpile food and water for base residents in case of an emergency, Hirata said.
“The Tokyo Metropolitan Government is telling people to have stocks for at least three days and if possible for a week,” he said.