和歌山における局所地震前後の微細土地変動の研究(第1報)

Abstract

Observations of change of ground-tilt and ground-strain have been made at two observa-tion stations of Oura and Akibasan in Wakayama City in Wakayama Prefecture since March1960. The aim of these obsrevations was to detect any minute ground deformation, if exist-ing, connected with the occurrence of local earthquakes frequently occurred in this area.It was found from results of the observations in more than one and half year that theground deformation observed was considerably affected both by oceanic tides of near sea andmeteorological changes.In this article the method of elimination of disturbing factor of oceanic tides and meteo-rological changes upon the ground deformation was introduced, and, after elimination, theresidual, anomalous ground deformation which were considered to be related intimately withthe occurrence of local earthquakes were discussed in detail.