A Hundred Years after the 1923 Great Kanto Earthquake How to Prepare for Disasters Caused by Combined Strikes of an Earthquake and a Typhoon, Both Simultaneous and Time-Lagged

The Great Kanto Earthquake that hit eastern Japan in 1923 caused approximately 105,000 causalities in Tokyo and surrounding areas. It is reported that about 90 percent of the victims were killed by fires, and one of the factors of expanding fires was strong winds brought by a typhoon developing near the Noto Peninsula on the day of the disaster. A series of landslides in Kanagawa Prefecture is also said to have been attributed to the typhoon-induced rainfall the day before. This paper analyses data from metrological observatories at the time to verify that the Great Kanto Earthquake was a complex disaster caused by combined strikes of earthquake and typhoon. The author also discusses the role of the media from a viewpoint of preventing confusions due to information disruption. It is indicated there have been several complex disasters with an earthquake and a typhoon striking simultaneously or with a time lag since 2000. From the perspective of “eliminating the unexpected,” which has been a major priority since the 2011 Great East Japan Earthquake, the author examined how media should confront these types of complex disasters, using a simulation originally devised by a disaster expert. This possibility of complex disasters was discussed, taking into consideration that some historically large earthquakes occurred in September, which is frequently hit by typhoons, examining how damages would be aggravated with simultaneous or time-lagged strikes of an earthquake and a typhoon, and pointing out the significance of considering new measures against such situations to be better prepared for disasters. On this occasion of 100 years after the Great Kanto Earthquake, the author examined the roles and missions of the media in their efforts to prevent damage by complex disasters, also considering the impact of global warming and the change in social structure.