Characteristics of the 2011 Tohoku Earthquake and Tsunami and Its Impact on the Northern Iwate Coast

Nationwide Post Event Survey and Analysis of the 2011 Tohoku Earthquake Tsunami

“…Sanriku was catastrophically impacted by the tsunami; this was caused by both undisturbed tsunami propagation and amplification inside the coastal bays from southern to mid-Sanriku (38.4-39.5 • N). However, the incident tsunami height was large along some parts of the northern Sanriku coastline, in the Taro and Noda areas, although the tsunami decayed inside the bays [Ogasawara et al, 2012].…”

“…Apart from Onagawa in the southern part of Sanriku, the mean inundation height in southern Sanriku is 10-15 m. Interestingly, the mean inundation height is large in the middle part of Sanriku between • N) rather than other areas. There are other large peaks of mean inundation height in the northern part of Sanriku, from Taro to Noda villages (39.75-40.10 • N) where this tsunami wreaked severe damages [Ogasawara et al, 2012]. On the other hand, the simulated maximum tsunami heights show slightly different distributions for the northern coast of Sanriku.…”

“…The survey areas were gradually expanded to all of the Tohoku region after the middle of April. Survey groups measured local tsunami heights along the coast stretching 2,000 km from Hokkaido in the north to Okinawa in the south, with the exception of a 30 km zone around the Fukushima Daiichi Nuclear Power Plant [Watanabe et al, 2012;Ogasawara et al, 2012;Shimozono et al, 2012;Gokon and Koshimura, 2012;Kakinuma et al, 2012;Udo et al, 2012;Tanaka et al, 2012;Mikami et al, 2012;Sasaki et al, 2012].…”

Improvement of Tsunami Countermeasures Based on Lessons from The 2011 Great East Japan Earthquake and Tsunami — Situation After Five Years

“…However, the 2011 tsunami made a serious nationwide impact [Mori et al, 2012], mainly in the Tohoku region [Suppasri et al, 2012a,b;Gokon and Koshimura, 2012;Kakinuma et al, 2012;Mikami et al, 2012;Ogasawara et al, 2012;Shimozono et al, 2012] and in other regions, from Hokkaido in the north Tokyo in the south [Sasaki et al, 2012]. This tsunami event exposed hidden weaknesses in Japan's tsunami disaster countermeasures.…”

Mechanisms of Coastal Dike Failure Induced by the Great East Japan Earthquake Tsunami

“…Kato et al (2007) showed patterns of coastal dike failure due to tsunami including destruction of the parapet during tsunami runup and backwash, and scouring at the landward slope and seaward toe. As for the Great East Japan Earthquake, failure of coastal dikes was reported in previous papers (Mikami et al, 2012;Ogasawara et al, 2012).…”