Abstract
Ten years have passed since the damage caused by the huge tsunami that occurred in
the 2011 Great East Japan Earthquake, and the actual situation has been elucidated and
future tsunami countermeasures are being discussed. First, regarding the tsunami generation
mechanism, inverse analysis is performed using not only seismic motion and geodetic data but
also tsunami waveforms, and characterization of the tsunami fault model has been proposed
for future evaluation. At that time, the Japan Meteorological Agency announced a tsunami
warning, but there were some issues to underestimate the tsunami heights.Therefore, research
such as real-time observation and improvement of prediction technology is now being
energetically conducted to solve this problem.
The behavior of the huge tsunami recorded in the photographs, videos, and survey data
at that time and its damage were overwhelming. The multiple, complex and chained damage
process related to tsunami is introduced and the classification of incentives and predisposing
factors for tsunami disasters, which will be useful for future disaster countermeasures. In
particular, this time, new disaster types such as topographic changes, tsunami fires, and
“black tsunamis” are reported. In the future, it will be important to simulate and evaluate
such tsunami-related disasters, and research is being conducted to overcome the problems of
conventional methods by utilizing the data obtained in the 2011 tsunami. Immediately after the
great earthquake, two levels of tsunami countermeasures and the “Tsunami Disaster Prevention
Town Development Law” were proposed by the national government, and efforts are being
made to reduce repeated disasters. Now, it is important to obtain a consensus on the safety
level in advance so that it can be reflected in the preliminary reconstruction plan.
