Earthquakes and Japan

Japan is one of the most earthquake-prone countries in the world, a fact that I was reminded of on Thursday morning when the Kanto region (where Tokyo and Gunma are located) got a big 6.7 magnitude shake that seemed to go on for two minutes or more. A staggering 20% of all earthquakes in the world occur in Japan, a chain of islands that sits astride four different tectonic plates, and one of the major challenges to the country has been how to apply its unique engineering skills to make sure buildings and people are safe. It’s a tribute to those skills that Thursday’s quake resulted in only a few injuries and no deaths, although it doesn’t always work out so well. The Great Hanshin Earthquake (Hanshin means “Osaka-Kobe”) of 1995 occurred in a region of Japan where strong quakes were less common, and as a result of lower building standards, a staggering 6400 people lost their lives. One of the features homebuilders tout on TV commercials in Japan is how well engineered their houses are, with special spring joints that allow the homes to rock back and forth flexibly in the event of shaking.