Near field monitoring of fault zone fluids at Atotsugawa active fault. -Examination of radical reaction

利用流体监测系统进行了以下研究，并钻取了穿透Atotsugawa断层带的岩心。（1）地壳气体连续监测装置的改进。（2）利用该仪器连续监测地壳气体;（3）利用断裂带岩心进行动态化学实验。虽然与本研究无关，但在车笼埔断裂带钻孔（台中）也曾做过类似的研究。为了检验我们的仪器是否适用于这个孔，我们参观了钻探现场，并与台湾的同事讨论。（1）地壳气体连续监测装置的改进：重点研究了天然地壳气体中的水蒸气的去除。除了现有的气体管线冷冻系统外，我们还开发了加热/冷冻装置，并将其安装到系统中。同时，通过减小气路体积，提高质谱仪的温度，提高了系统的准确度和精密度。结果，我们在连续监测的条件下确认了3 He峰。我们将进一步修改机器，以实现3 He的定量和连续监测。（2）断裂带天然气同位素组成的连续监测改造后，开始了地壳天然气的连续监测。除氦的同位素组成外，获得了连续的气体组成数据。不幸的是，即使是M4.0级地震也从未发生在钻孔附近。我们仍在等待地震，地震应该大于M4.0，靠近我们的钻孔。（3）断裂带岩心材料的动态化学反应实验：流体与岩心材料碎片的一系列粉碎和反应实验。我们证实了在研磨实验过程中的甲烷排放。阐明了甲烷释放的根本过程是在压裂前形成的流体包裹体的破裂。

Following researches had been performed using fluid monitoring system, and drilled core penetrating the Atotsugawa fault zone. (1)Improvements of continuous monitoring apparatus for crustal gas. (2)Continuous monitoring of crustal gas using the apparatus and (3)Dynamic chemical experiments using fault zone core. Although it is not directory related to this research, similar project has been done at Chelungpu fault zone drilling hole (Tai-Chung). In order to examine whether our apparatus can be available for this hole, we visit the drilling site and discuss with colleagues in Taiwan.(1)Improvements of continuous monitoring apparatus for crustal gas.We focused our effort to remove the water vapor contained in natural crustal gas. In addition to the pre-existing freezing system of gas line, we develop Heating-up/Freezing Unit and install it to the system. At the same time, we improve the accuracy and precision of the system by reducing the volume of gas line, and keeping higher temperature for the mass spectorometer. As a result, we confirmed 3He peak under the condition of continuous monitoring. We will further modify the machine to achieve quantitative and continuous monitoring of 3He.(2)Continuous monitoring the isotopic components of fault zone gasAfter the modification, we started continuous monitoring of crustal gas. Continuous data of gas composition has been obtained except isotopic composition of Helium. Unfortunately, even M4.0 class earthquakes never occurred close to the drill hole. We are still waiting the earthquake which should be larger than M4.0 and close to our drill hole.(3)Dynamic chemical reaction experiments using fault zone core materials.A series of comminution and reaction experiments between fluid and fragments of core materials. We confirmed that Methane emission during grinding experiments. We clarified that fundamental process of emission of methane is breakdown of fluid inclusions which was generated predated fracturing.