Initial field survey report of the 2011 East Japan Tsunami in Sendai, Natori and Iwanuma Cities

The East Japan Earthquake (Mw 9.0) and associated tsunami struck the Pacific coast of eastern Japan on March 11th, 2011 at 2:46 p.m. (Japan Standard Time). Maximum run-up heights reached about 40 m along the Sanriku region’s coast and around 10 m on the Sendai coastline. The coasts of Iwate, Miyagi and Fukushima Prefectures in particular were badly damaged, and a considerable amount of time and money will be required to restore these areas. Tsunami inundation up to 5 km inland occurred across the Sendai Plain, which remained partly flooded for several weeks after the event. Some areas were still under water 2 months after the earthquake, and are likely to remain flooded for some time as a result of subsidence. The Disaster Control Research Center at Tohoku University conducted scientific research of the inundated coastal plains of Sendai, Natori and Iwanuma Cities in collaboration with other research institutes from Japan and overseas with the support of UNESCO-IOC (Intergovernmental Oceanographic Commission). Data and samples collected during the field survey are now being analyzed by various institutes around the World. This report is a summary of our field survey that focused on an area to the north of Sendai Airport. Radioactivity data recorded at the time of survey are also provided.