摘要
A massive earthquake occurred in the Tohoku and Kanto regions of Japan on the 1 lth of March 2011. In response, a tsunami alert, a tsunami warning and an advisory were issued for the entire Pacific coast region. This research investigates the evacuation behavior of ships by AIS （automatic identification system） data in Onahama port after the tsunami warning was issued. The unusual behavior observed was attributed to the emergency evacuation of ships. This research investigates the evacuation behaviors of the vessels using the data obtained from AIS, around the Onahama Port during alerting the major tsunami warning. The result shows that most vessels in the port started evacuating approximately 10 min after the major tsunami warning and completed offshore evacuation 40 min after this warning. This contributed in understanding the actual status of the vessel evacuation. In addition, the travel paths of each vessel revealed the influence of the tsunami on the vessels. Furthermore, the exceptional situation where several vessels moved in the same direction at the speed almost same for about 2 hours was confirmed. As a result, it can be estimated that the waves that affected both vessels were the drawback of the tsunamis.
