The M9.1 Tohoku-oki Earthquake of 2011: Implications for Seismic and Tsunami Hazards in Japan and Cascadia: A Presentation by Dr. Jim Mori

The M9.1 Tohoku-oki Earthquake of 2011: Implications for Seismic and Tsunami Hazards in Japan and Cascadia
A Presentation by Dr. Jim Mori
Kyoto University
Hosted by the Center for Japanese Studies

The M9.1 earthquake on March 11, 2011 was the largest known seismic event for a country that has historical documents that span about 2000 years. The huge earthquake caused intense shaking over a large area of northeast Japan and a devastating tsunami that destroyed many coastal areas. Despite the severe ground motions, the number of collapsed buildings was relatively low for an earthquake of this size, although there were areas of severe damage in Sendai and tall buildings in Tokyo were visibly swaying. The earthquake caused 18,419 deaths with over 90% attributed to the tsunami. It was a sobering result for a country that has an advanced tsunami warning system (probably best in the world) and a population that is well educated in safety issues for natural hazards, because of the frequent typhoons, landslides, volcanoes and earthquakes. At the time of the earthquake, the Earthquake Early Warning and Tsunami Warning systems worked well technically. Warnings for strong shaking were broadcast within 40 sec of the earthquake origin time. Tsunami warnings were issued tens of minutes before arrivals of large water waves.

Why was there such a large loss of lives? There are no simple answers and combinations of communication, logistics and other societal factors contributed to the problem. Lessons learned from the 2011 Tohoku-oki earthquake are obviously important for Japan and other region, such as Cascadia, that are prone to future large earthquakes.

5:30 PM | Tuesday, OCtober 27, 2026
Smith Memorial Student Union
Room 327/8/9
Free and Open to the Public
Please use the entrance on SW Broadway

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