[S-VC28] Active Volcanism

[SVC28-27] Development of an automatic volcanic plume sampler SelPS for UAS

*Urumu Tsunogai¹, Ryo Shingubara¹, Masanori Ito¹, Yuhei Morishita¹, Fumiko Nakagawa¹, Shin Yoshikawa², Mitsuru Utsugi², Akihiko Yokoo² (1.Graduate School of Environmental Studies, Nagoya University, 2.Graduate School of Science, Kyoto University)

Keywords:fumarolic gases, volcanic plume, carbon dioxide, Unoccupied Aerial Systems, automatic volcanic plume sampler

Both chemical and isotopic compositions of volcanic plumes are highly useful in evaluating the present status of active volcanoes. Monitoring their temporal changes can facilitate the forecasts of volcanic activity as well. In the present study, we developed a drone-borne automatic sampler for volcanic plumes in which an output signal from a sulfur dioxide (SO₂) sensor triggered a pump to collect samples when its SO₂ concentration exceeded a predefined threshold. We fitted the sampler on a drone at Nakadake central cone, Aso volcano, Japan, where only the crater rim was accessible.

In the sampling campaign done on October 2020, good consistency in isotope ratios (²H/¹H) of molecular hydrogen (H₂) between samples collected by the automatic sampler and those collected directly into pre-evacuated flasks was obtained. Furthermore, by using the drone-borne sampler at Aso volcano, we obtained plume samples with much higher concentrations of H₂ and carbon dioxide (CO₂) than those taken directly into flasks at the crater rim. Our sampler can be utilized to collect volcanic plume samples for the determination of stable isotopic compositions in general by subsequent laboratory analysis and the remote establishment of fumarole outlet temperature based on the ²H/¹H ratios of hydrogen, including their temporal changes. This study was supported by MEXT Integrated Program for Next Generation Volcano Research and Human Resource Development (Theme B).