Abstract
Some indications of the possibility of a large earthquake occurrence around Kyoto in the near future are to be found in three kinds of data: auto-correlation curve of destructive earthquake occurrence around Kyoto since the 7th century, annual sums of accelerations caused by felt earthquakes near Kyoto since 1891 and results from precise levelings along a route from Fukuchiyama to Kyoto since 1887. To examine the possibility of occurrence of the said earthquake, data obtained by observations of crustal linear strains and tilts performed at Osakayama since 1951, some observations having been augmented in the period from 1961 to 1970, were analyzed. Average secular changes were estimated by fitting a typical formula to monthly values from moving averages of 13 months, and deviations of these monthly values from the formula-fitted average secular changes (anomalies) were compared with changes in ground-water level and annual frequency of felt earthquakes. Partial-correlation between the annual means of the observed anomalies in crustal movement at Osakayama and the annual frequency of felt earthquakes is remarkable in most parts of the observations. From the anomalies of crustal deformation, no definite conclusion could be drawn concerning an approaching large earthquake.
