The Sanriku coast of Tohoku had been devastated by
previous tsunamis. The 1896 Sanriku earthquake, a typical
“tsunami earthquake,” caused large tsunami, with the
maximum height of 38 m, despite its weak ground shaking.
The 2011 tsunami heights along the Sanriku coast
were as high as nearly 40 m, roughly similar to the 1896
tsunami heights. The 1896 tsunami caused about
22,000 casualties, slightly more than the 2011 tsunami.
Study of tsunami waveforms indicate that the 1896 earthquake
was generated from a fault motion near the trench
axis, similar to other “tsunami earthquakes.”