September 2023 marks the centenary in Japan of the worst natural disaster to hit the country — the Kantō earthquakes. As a volcanic archipelago, Japan lies in a meeting zone of four tectonic plates. The movement of those plates can lead to particularly violent earthquakes that also give rise to tsunamis. Being used to dealing with earthquakes of variable intensity (Iwate in 2008, Tōhoku in 2011, which caused the tsunami that led to the Fukushima nuclear accident, Kumamoto in 2016 etc.), the country has adapted to the situation. On the other hand, it may not be adequately prepared for a so-called ‘Big One’: an exceptional massive disaster event, which is a very low-probability occurrence, but one which might have monumental consequences, up to and including the country’s total collapse.
In this article, Jean-François Heimburger underscores why and to what extent Japan is not immune to the occurrence of such a ‘megaquake’, detailing the attendant issues and vulnerabilities. He goes over a number of previous lesser-scale events that allow us to grasp the impact such a disaster might have and assess some of the damage that would ensue. Lastly, not yielding to the resignation or fatalism of many in the Japanese population, he lists a series of preventive measures to be implemented to cope with such an event and improve resilience. These cover construction, housing and infrastructure etc., but also information and response-planning (the evacuation of populations, their protection etc.) in situations of imminent risk or in the early minutes of an actual disaster. The worst will not necessarily happen, but the task of foresight is to prepare for such an eventuality. This article contributes to that preparation.