抄録
Many geochemical anomalies associated with earthquakes have been reported after World War II. Such seismo-geochemical observations have been carried out mainly in Japan, the former Soviet Union, China, and the United States. Major components measured in the observations are radon, hydrogen, and helium as well as dissolved ion species which are issued from underground. Radon has been widely monitored in the observations because it is easily detected by radioactivity. Multiple chemical species in spring gas and groundwater can be easily analyzed by gas chromatography and ion chromatography, respectively. The mechanism causing the geochemical anomalies has not been fully clarified yet, but some results of geochemical observations correspond with those of geophysical ones. More extensive seismo-geochemical observations should help us to develop earthquake prediction research.
