An earthquake accompanied by a huge tsunami will wash away not only structures but also many people, leading to an increase in missing people and deaths. It is important to know how the tsunami victims were washed away in order to strengthen tsunami countermeasures in the future. In this study, we reproduced the drifting behavior using numerical simulations for humans and showed that the drifting behavior offshore can be qualitatively expressed. The presented method is likely to be used for the estimation of tsunami driven drifting victims.
Japan is one of the most earthquake-prone countries in the world and has been damaged by earthquakes and tsunamis many times in the past.
A magnitude 9.0 earthquake with an epicenter off Sanriku occurred at around 14:46 on March 11, 2011, causing enormous earthquakes and tsunami damage mainly in eastern Japan. The tsunami caused by this earthquake caused not only flooding but also secondary damage caused by the collapse of houses, the generation of debris, and the drifting of vehicles, containers, and ships.
The 2011 Tohoku-oki earthquake is a disaster with different characteristics from the 1923 Great Kanto Earthquake and the 1995 Great Hanshin-Awaji Earthquake.
First, the earthquake destroyed the bedrock 400km north-south and 200km east-west off Ibaraki prefecture from Iwate prefecture, and the damage was particularly severe mainly in Iwate prefecture, Miyagi prefecture, and Fukushima prefecture. Great damage has also occurred in Aomori, Ibaraki, and Chiba prefectures. A huge tsunami occurred, and the disaster areas 500km north and south are scattered in the inner part of the bay on the ria coast, and the damage is various.
Second, more than 90% of the victims died in the Tohoku-oki earthquake due to being involved in the tsunami. Many bodies have been found far away from their place of residence. On the other hand, most of the causes of death of the victims in the 1995 Great Hanshin-Awaji Earthquake were suffocation and crushing death due to the underlay of a collapsed house (The White Paper on Police, 2012).
