Comparison between Slip Distributions in the 2011 Tohoku Earthquake Tsunami Evaluated by Different Methods for Considering Tsunami Generation by Horizontal Crustal Displacement

In order to evaluate the effects of horizontal crustal displacement on tsunami generation, the joint-inversion analysis and tsunami propagation analysis were conducted for the 2011 Tohoku earthquake tsunami using the method of Tanioka and Satake (1996), hereinafter referred to as the TS method, as well as a conventional one. We then compared the slip distributions evaluated by the two methods. In the entire tsunami source model, the slip area, average slip and the seismic moment with the TS method were about 90%, 90% and 84%, respectively, in comparison with those with the conventional one, and therefore, the effects of the method to consider horizontal crustal displacement were confirmed. While the average slip in the areas parallel to the trench axis with the TS method was highest in the area along the trench, the conventional method yielded the highest average slip values in a little deeper areas. The slip distribution by the TS method were reflected the actual phenomenon more in comparison with a conventional one.