Abstract
We have constructed a three-dimensional (3D) model of geological structure of a seismic gap region south of the 2004 Mid Niigata Earthquake with a recently-proposed 3D modeling method using constraints of geotectonic history revealed by geological studies. The large-scale, say 64 km x 33 km, 3D geological structure was successfully modeled on the basis of surface geological maps, a relatively small amount of exploration data and the information of the important geotectonic processes. We have poin ed out an advantage and a disadvantage of the method: This method is considered to be a powerful tool to construct and revise a three-dimensional model of a region without sufficient exploration data, and to be appropriate for such a large-scale region in view of the simplification incorporated to the model. We consider that the resultant 3D model can be used for a strong ground motion prediction in the future earthquake region.
