Stress field in a semi-infinite elastic medium due to internal stress sources, and an interpretation of tectonics in and around Japan.

Abstract

This paper investigates the stress field in the interior of a semi-infinite elastic medium due to internal stress sources. Importance of strain nuclei as sources of the internal stress is emphasized. Patterns of the stress changes induced by introducing a simple strain nucleus are illustrated with the aid of equal area projection. The internal stress field in and around Japan is calculated by distributing double couple point sources on the deep-seismic plane with their compressional axes parallel to the dip of the descending plates, and the results obtained are projected on a Mercator map. Such a model may explain the actual stress field in this region at least to some extent.