@article{oai:nagoya.repo.nii.ac.jp:00001438,
 author = {Ito, Takamori},
 journal = {The Journal of earth and planetary sciences, Nagoya University},
 month = {},
 note = {Continual monitoring data of gas bubbles at Hoshina spa near Matsushiro, Nagano Prefecture, central Japan, showed three coseismic anomalies in the period from 1989 to 1994. The respective anomalies were associated with three nearby earthquakes with M=3-4 and focal distances less than 10 km. They are characterized commonly by sudden decreases of He/Ar ratio and sluggish recoveries of the ratio over more than one month. These seismo-geochemical anomalies can be interpreted as the result of decreased pore pressures in the reservoir filled with deep groundwater with a high concentration of He relative to shallow groundwater. The decreases of pore pressure could be caused by crustal stress/strain changes accompanied by the respective nearby earth-quakes, but possibly not by the ground motion due to seimic waves. The gas monitoring results at Hoshina spa suggest that the behavior of subsurface gases is sensitive to the change in crustal stress/strain conditions., 国立情報学研究所で電子化したコンテンツを使用している。},
 pages = {37--47},
 title = {Seismo-geochemical anomalies of He/Ar ratio gas bubbles at Hoshina spa near Matsushiro, Nagano Prefecture, central Japan},
 volume = {47},
 year = {2000}
}