著者

宮川 歩夢 名和 一成 山谷 祐介 大滝 壽樹 杉原 光彦 奥田 隆 住田 達哉

出版者

国立研究開発法人 産業技術総合研究所 地質調査総合センター

雑誌

地質調査研究報告 (ISSN:13464272)

巻号頁・発行日

vol.71, no.2, pp.63-76, 2020-04-27 (Released:2020-05-07)

参考文献数

17

被引用文献数

1

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国立天文台VERA石垣島観測局を中心とした名蔵川流域において,地下の地質構造を反映すると考えられる重力異常を明らかにするために重力測定を実施した.この重力測定では絶対重力測定及び周辺での相対重力測定を組み合わせている.絶対重力測定は国立天文台VERA石垣島観測局の重力計基台において,また相対重力測定は周辺域の62地点において実施した.得られた重力測定結果に既存の重力データを加え,重力異常図を作成した.おもとこれにより,名蔵湾から於茂登岳だけに向かって,負の重力 異常が大きくなる傾向がみられた.これは,於茂登岳を構成する漸新世の珪長質深成岩が周囲のジュラ紀付加体に比べて密度が低いことによると考えられる.さらに於茂登岳麓から名蔵湾にかけて負の重力異常の帯が確認された.このことは,名蔵湾から於茂登岳に向かう局所的な基盤形状を反映し,密度の低い堆積層が埋める埋没谷の存在を示唆する.

著者

名和 一成 杉原 光彦 村田 泰章 風間 卓仁 西田 究 菅野 貴之 小山 悦郎 大久保 修平 奥田 隆

出版者

日本測地学会

雑誌

測地学会誌 (ISSN:00380830)

巻号頁・発行日

vol.54, no.2, pp.59-67, 2008 (Released:2013-02-25)

参考文献数

17

被引用文献数

1

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We carried out continuous gravity observation with a Scintrex CG-3M gravimeter at Asama Volcano Observatory from September 4 to October 22 in 2007.We tried to detect hydrological gravity effects after heavy rainfall by Typhoon 200709 (FITOW). To detect hydrological gravity effects we supposed a simple tank model as proposed for the Matsushiro superconducting gravimeter observation, which model represented immediate gravity increase and gradual decrease after rainfall. Parameters of the tank model were estimated using an ABIC minimization iversion method and precipitation data as inputs. As a result, hydrological gravity effects were extracted from gravity residuals although gravity residuals included a large non-linear drift. And the extracted hydrological gravity effects corresponded to temporal gravity changes simultaneously observed with an FG5 absolute gravimeter. Our success promises expanding opportunities of continuous observation by using CG-3M gravimeters in the future.

著者

徂徠 正夫 後藤 宏樹 杉原 光彦 西 祐司 中尾 信典

出版者

一般社団法人 資源・素材学会

雑誌

Journal of MMIJ (ISSN:18816118)

巻号頁・発行日

vol.137, no.4, pp.46-50, 2021-04-30 (Released:2021-04-28)

参考文献数

17

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Toward the implementation of geological CO2 storage, cost reduction of CO2 monitoring during and after injection into targeted reservoirs is the key issue. The continuous gravity measurement using a superconducting gravimeter, which has been applied to the demonstration project site in Japan ahead of the rest of the world, has a potential to resolve the issue from the viewpoint of a complement to the high-cost seismic survey. The concept is such that the continuous gravity measurement is substituted for constant monitoring and that the use of seismic survey could be limited only when any anomaly is detected. The comparison of the monitoring cost after the completion of CO2 injection indicated that applying gravity measurement can reduce costs by up to 15 to 50% of the seismic cost. The current detection limit of gravity change is around 1 μGal based on the application result in the coastal area in Japan. However, the time series analysis using pseudo gravity data suggested the possibility of anomaly detection even below the detection limit. Further improvement of analysis precision would lead not only to more rapid and more reliable anomaly detection but also to contribution to the cost reduction during the CO2 injection period.