- 第3日 5月17日（木） 15:25～15:45 C会場（星雲2）
To evaluate activities of volcanoes, hydrothermal water and environmental water input from deeper part through cracking by ascending magma, noble gas abundance and isotope ratios are useful proxy. For this purpose, Helium isotope ratios are widely applied. Further, even in submarine environment, accurate estimation of deep-input to submarine volcanoes are desired to evaluate the flux and their temporal variation, which are anticipated as the ultimate driving forces for submarine hydrothermal activity.
The new preparation system for such types of noble gas measurement consists of following components: the water preparations system, composite gettering system (halogen getter, sulfide getter and Ti-Zr getter), cryogenic pump, SAES-getter pump (SORB-AC) and charcoal trap to analyze the all noble gases (He, Ne, Ar, Kr and Xe). The three types of getters effectively remove halogens, sulfides, abundant water vapor and other active gases within ten minutes for respective gettering step. Finally, we enabled to find the contribution from magmatic composition using He isotopic ratio. Here we discuss such a contribution for magmatic noble gas and the magma plumbing system, by analyzing water sampled from a lake and hot spring.