Abstract
Apparent coseismic temperature changes in the groundwater of a well located near the Usu volcano, Hokkaido, Japan, have been observed at the time of occurrence of volcanic earthquakes. These changes were not necessarily associated with all earthquakes but were likely to be associated particularly with earthquakes having the following two characteristics:
1. Earthquakes with large seismic intensity
2. Earthquakes occurring outside the outer rim of the Usu volcano.
