1967 Volume 76 Issue 2 Pages 76-86
In this report, the changes of discharge and temperature of thermal water of Kagai hotspring area are described in the relation with the frequency of Matsushiro Earthquakes.
During the period of activity, it was observed that discharge of thermal water was increased before remarkable trembling had occured. This might be one of predictive phenomena of occurring of earthquakes.
According to the measurement of heat flow of thermal water, the change of value could be seen every twenty two days' interval, which suggests to be associated with activity of earthquakes.
From the data on earthquakes and hotsprings, it may be considered that the Matsushiro Earthquakes have been caused by pushing up of deep-reserved thermal water, characterized by relatively low temperature and high contents of CO2 and Cl- into geologically weak zone.