火山性の温泉地における地中ガスの挙動

―ヘリコプターからのリモートセンシング―

抄録

Aerial environmental gamma ray measurements by an advanced helicopter were carried out to clarify a behavior of radon and thoron as bed gases in regions of hot springs with high temperature, over Minami-Kayabe area in Hokkaido, Asama-Shirane area in Gunma Pref., and Azusa R. area in Nagano Pref.. As a result, some interesting facts were confirmed for bed gases behaviors in these regions, a) on intensities of radon and thoron, b) on relations of thoron and thoron/radon with temperature of hot springs, c) on reservoirs of hot fluid under the deeper ground, and d) on geothermal structures and so on.