Case 24 reevaluation of anomalous vertical crustal movement associated with the 1964 Niigata, Japan, earthquake

Abstract

It is widely acknowledged that the 1964 Niigata, Japan, earthquake is associated with the preseismic anomalous crustal movement detected by repetition of precise levelings, while some doubts have been raised on the validity of reported precursory movement. Validity of the crustal movement is tested by an analysis of tidal data. When we are able to deduce crustal movement referring to the determined mean sea level, we can discuss the absolute crustal movement. Tidal data along the Japan Sea coast of northeast Japan are analyzed by the method developed inTsumura (1963, 1970) for the period from 1955 to 1986.