Development of an exploration method of high density measurements of stable isotopes of water samples for prompt geothermal explorations in the geothermal exploitation base, northern Honshu, Japan

2016 Fiscal Year Final Research Report

• Project/Area Number: 26281053
• Research Category: Grant-in-Aid for Scientific Research (B)
• Allocation Type: Partial Multi-year Fund
• Section: 一般
• Research Field: Design and evaluation of sustainable and environmental conscious system
• Research Institution: Hirosaki University
• Principal Investigator: MURAOKA Hirofumi 弘前大学, 北日本新エネルギー研究所, 教授 (20358146)
• Co-Investigator(Kenkyū-buntansha): 井岡 聖一郎 弘前大学, 北日本新エネルギー研究所, 准教授 (40598520) ; 上田 晃 富山大学, 理工学研究部, 教授 (90456799)
• Project Period (FY): 2014-04-01 – 2017-03-31
• Keywords: 地熱探査 / 断裂 / 断層 / 珪化変質帯 / pH / 地熱開発 / 開発リードタイム

Outline of Final Research Achievements

This study developed the stream and spring water pH mapping technique as a prompt and low-cost geothermal exploration method. This method is an ultimately prompt exploration method to be completed on the notebook computer on the survey fields. The volcanic center yields acid hot water by the condensation of rising volcanic gas, whereas the volcanic foot yields neutral water by mixing amounts of meteoric water. If there is a reservoir fault hosting matured and neutral hot water on the volcanic slope, a concentric pH contours would be disturbed by the shadow effect to the rising volcanic gas or by the up-flow of the reservoir water. Actually, the Mutsu Hiuchi Dake East Slope Fault found by our surveys shows a neutral pH anomaly zone on the pH map. This method enables to detect not only reservoirs but also the neutral pH characteristic of the reservoir water. This method provided a solution to the acid water problem for the geothermal development in the Mutsu Hiuchi Dake geothermal field.

Free Research Field

地熱地質学