[S-GD02] Geodesy and Global Geodetic Observing System

[SGD02-P04] Superconducting gravimeter observation at Mt. Asama

*Yuichi Imanishi¹, Hiroshi Ikeda², Takahito Kazama³, Ryo Honda⁴, Hiroshi Tsuji¹, Ryuichi Nishiyama¹, Keigo Yamamoto⁵, Kazunari Nawa⁶ (1.Earthquake Research Institute, The University of Tokyo, 2.SK Service, 3.Faculty of Science, Kyoto University, 4.Mount Fuji Research Institute, Yamanashi Prefectural Government, 5.Disaster Prevention Research Institute, Kyoto University, 6.National Institute of Advanced Industrial Science and Technology)

Keywords:Mt. Asama, superconducting gravimeter, super-hybrid gravity measurement, underground water

We will report on the gravity observation with the superconducting gravimeter iGrav #003 at Mt. Asama. The iGrav #003, which has been used in Alaska and Mt. Zao, is now under management of Earthquake Research Institute, the University of Tokyo. After 4-month pilot observation at Mount Fuji Research Institute, Yamanashi Prefectural Government, we moved the instrument to the Asama Volcano Observatory, Earthquake Research Institute in November 2024. The gravimeter was installed in the space called the “pump room” in the older building of the observatory.

The main purpose of this observation is to develop a technique of advanced gravity survey (the super-hybrid gravity measurements) based on a superconducting gravimeter to precisely track temporal density changes beneath active volcanoes. We further plan to make water flow measurements for studying the effects of underground water, as well as absolute gravity measurements for calibrating instrumental drift of the superconducting gravimeter. We will show outline of the observation and some initial results of data analysis.