Japan Earthquake—When the Big One Hit [Associate Editor's View]

Japan is among the most earthquake-prone countries in the world. It lies across four slabs of rock, known as tectonic plates, that cause earthquakes when they rub against each other. Experts believe that Tokyo, which sits on a major fault line, has been overdue for a strong earthquake for decades. The problem, according to Prof. Keiji Doi from Tokyo University´s Earthquake Research Institute, is there´s no way of knowing when it will happen.