1996 年 49 巻 1 号 p. 27-38
The Tonankai earthquake of December 7, 1944 occurred on the upper plane of the subducted slab located at the boundary between the Philippine Sea plate and the Eurasian plate. Recently it was pointed out that in the Kumano-coast region, the southeast part of the Kii Peninsula, the direction of the strike of the subducting Philippine Sea plate runs from southwest to northeast, while in the Ensyu-coast region, which is located between Nagoya and Shizuoka, the direction runs from east to west. We assumed that the dislocation of seismic faulting took place on the determined plate boundary and the dislocation is equal on each fault plane. As the plate boundary discontinues beneath the Ise Bay, two different fault planes were considered in our fault model: the one is located along the Kumano-coast on which the amount of slip is 200cm and its direction is N50°E, and the other is along the Ensyu-coast on which the amount of slip is 50cm and its direction is N50°E. We checked that the crustal movement calculated by our model is similar to the observed pattern. We carried out a numerical simulation of the tsunami based on our model. It was found that the sea level changes calculated by our model agreed well with the tide gauge records at four stations on the coast of the Ise Bay.