著者

井岡 聖一郎 岩月 輝希 酒井 利彰 石島 洋二

出版者

日本水文科学会

雑誌

日本水文科学会誌 (ISSN:13429612)

巻号頁・発行日

vol.37, no.4, pp.287-293, 2007-11-30 (Released:2009-03-27)

参考文献数

33

被引用文献数

1 2

---

Redox potential (Eh) is one of the most important physico-chemical properties of groundwater. Groundwater Eh have been studied in terms of safety of high-level radioactive waste disposals, water resource management and so on. As the results, it is getting clear that redox potential of deep groundwater in sedimentary and crystalline rocks have a remarkable variability. For example, some reported Eh values of deep groundwater decrease with increasing depth, i.e. with residence time. However, there are few reports showing data measured in situ. Only some Eh values of deep groundwater measured from research borehole drilled at crystalline rocks in Japan and Sweden have been reported. Between 200 and 1000m depth, the Eh values of the deep groundwater range from about 0 to -400mV.This essay first briefly summarizes methodology for Eh measurement and reports Eh values of deep groundwater. Then, it discusses the remaining issues of Eh measurement that are to develop of measurement technology applicable for various geological environments and to understand the redox evolution process through the groundwater flow system.

著者

松田 雅司 鈴木 陽大 井岡 聖一郎 村岡 洋文

出版者

日本地熱学会

雑誌

日本地熱学会誌 (ISSN:03886735)

巻号頁・発行日

vol.39, no.2, pp.73-79, 2017-04-25 (Released:2017-10-26)

参考文献数

19

---

The southwestern foot of the Hakkoda–Odake volcano has many geothermal manifestations where geothermal development has been limited by the Natural Parks Law. The current target area, which is classified as Class II special zone has been deregulated for individual geothermal development. We conducted an investigation to determine the chemical and isotopic characteristics of the hot waters around the Shinyu Fault and to estimate the temperature of the geothermal reservoir. According to our δD–δ18O diagram, the hot waters in the study area are meteoric in origin. In addition, the triangle diagram for Cl–, SO42–, and HCO3– concentrations indicates that these hot waters can be classified as steam-heated waters and volcanic waters. The B/Cl and Br/Cl ratios show that the volcanic waters are diluted with shallow groundwater as they flow through Jigokunuma downstream to Shinyu. We estimated the geothermal reservoir temperature to be between approximately 150 and 160 °C, based on anhydrite geothermometry and the chloride–enthalpy mixing diagram.

著者

井岡 聖一郎 藤井 光

出版者

弘前大学

雑誌

基盤研究(C)

巻号頁・発行日

2013-04-01

---

浅層地盤を対象に地盤の見かけ熱伝導率の変動メカニズムの解明とその変動の結果もたらされる熱交換資源量評価を目的として,長さ約8mの地中熱交換器を設置し熱応答試験を実施した。浅層地盤の見かけ熱伝導率の変動を引き起こす要素として地下水面深度の違いを想定し,地下水面深度が異なる5月と9月に熱応答試験を実施した。その結果,地下水面深度が深い9月の試験結果は,熱交換量が少なく熱応答試験の出口温度が5月より高い値を示した。したがって,本研究で対象とした浅層地盤の見かけ熱伝導率変動メカニズムの要因として,地下水面深度の変動が重要であり,地下水面深度が深くなれば,熱交換資源量が小さくなることが示された。