日本地球惑星科学連合2018年大会

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[JJ] ポスター発表

セッション記号 A (大気水圏科学) » A-HW 水文・陸水・地下水学・水環境

[A-HW24] 熊本地震に伴う地表水と地下水の変化

2018年5月22日(火) 10:45 〜 12:15 ポスター会場 (幕張メッセ国際展示場 7ホール)

コンビーナ:嶋田 純(熊本大学大学院自然科学研究科)、中川 啓(長崎大学大学院水産・環境科学総合研究科)、細野 高啓(熊本大学大学院先導機構、共同)、林 武司(秋田大学教育文化学部)

[AHW24-P07] 微量元素濃度組成と金属元素同位体比からみた熊本地域地下水の地域的特徴と熊本地震による影響評価

杉本 直人1、*谷水 雅治1細野 高啓2 (1.関西学院大学、2.熊本大学大学院先導機構)

キーワード:地下水、同位体

In these last few decades, isotopic traces have been used to understand the origin and flow of groundwater. In this study, we analyzed various isotopes from groundwater samples in Kumamoto area, Japan. Groundwater in this area is supplied from Mt, Aso, and utilized as a main source of water supply in Kumamoto City. Its recharge by meteoric water is the main source as indicated by conventional delta-18O and delta-D isotopes of water, but additional inputs from different sources are suggested. In this study we tried to detect the presence of additional sources using delta-11B and delta-7Li isotope ratios dissolved in water as well as concentrations of B, Li, and major dissolved ions, and D/H-18O/16O values of H2O. B and Li are conservative trace elements in typical groundwater system (pH, Eh, EC), and these isotopes have very wide variations(0-30 permil) in nature owing to its relative large mass differences. Stagnant groundwater and thermal fluids tend to have low delta-values and seawater has high values, so the isotope systematics are useful to estimate origin of groundwater.