SEGJ Technical Conference

Seismic velocity structure beneath the middle to deeper part of the Shimokita Peninsula, Northeast Japan as revealed by the joint analysis of sea and land seismic reflection and refraction data

Abstract A joint analysis of the data obtained by seismic reflection and refraction survey, with special reference to the existence of faults and folds structure assumed to extend thorough land from sea revealed detailed seismic velocity structure from the shallow to the deeper part of the Shimokita Peninsula, Northeast Japan. The main characteristics of the seismic velocity structure were summarized as follows: (1) A low velocity layer, having a small-scale basin structure, is clearly distributed to a maximum depth of about 2,500m extends from the eastern part of the land region toward the offshore of the Pacific Ocean. (2) A few strong seismic reflectors, with dipping to the westward, are situated in the western part of the land region extending toward the offshore of the Mustu Bay. In this survey, we succeeded to illustrate the detailed seismic velocity structure and find the basin and the folds structure beneath the Shimokita Peninsula.