Kazuyoshi Asai, Maki Tsujimura, Wilson Yetoh Fantong and Hiroshi Satake
Release Date: June 30, 2011

Impact of natural and local anthropogenic SF6 sources on dating springs and groundwater using SF6 in central Japan

Kazuyoshi Asai1), Maki Tsujimura2), Wilson Yetoh Fantong3)4) and Hiroshi Satake5)

1) Geo-Science Laboratory Co. Ltd.
2) Graduate School of Life and Environmental Sciences, University of Tsukuba
3) Graduate School of Science and Engineering, University of Toyama
4) Institute of Mining and Geological Research (IRGM)
5) Department of Environmental Biology and Chemistry, University of Toyama

(Received: July 21, 2010)
(Accepted for publication: May 31, 2011)

Abstract:
Sulfur hexafluoride (SF6) concentrations in springs and groundwater were measured in the Chubu region of central Japan to evaluate the impact of natural and local anthropogenic SF6 and the validity of SF6 for dating young groundwater in Japan. Sampled water showed detectable concentrations of SF6 at 0.21–125 f mol/L. Most of the mountain springs have SF6 concentration assumed by the dissolution of the clean ambient air in Northern hemisphere. The SF6-based apparent ages for the mountainous springs were estimated at less than 6 years in smaller catchment areas (< 0.5 km2), and ranged from 4 to 32 years in the larger catchment areas located on the Quaternary volcanoes. The SF6 ages for mountain springs were consistent with the scale of groundwater flow and with previously determined 3H ages for groundwater in similar settings in Japan, suggesting the loading of natural SF6 in the groundwater is relatively small in the mountainous areas. In the plains, local industrial activities led to high concentrations of SF6 in some of the analyzed groundwater. The results suggest SF6 can be an effective dating tool for young groundwater in Japan, when and where the input of local anthropogenic SF6 is negligible.

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To cite this article:
Kazuyoshi Asai, Maki Tsujimura, Wilson Yetoh Fantong and Hiroshi Satake: “Impact of natural and local anthropogenic SF6 sources on dating springs and groundwater using SF6 in central Japan”, Hydrological Research Letters, Vol. 5, pp.42-46, (2011) .

doi:10.3178/hrl.5.42
JOI JST.JSTAGE/hrl/5.42
Copyright (c) 2011 Japan Society of Hydrology and Water Resources