JpGU-AGU Joint Meeting 2017

Presentation information

[JJ] Oral

S (Solid Earth Sciences) » S-CG Complex & General

[S-CG75] [JJ] Crustal fluids and deformation

Sun. May 21, 2017 1:45 PM - 3:15 PM 106 (International Conference Hall 1F)

convener:Naoji Koizumi(School of Environmental Science,the University of Shiga Prefecture), Koji Umeda(Hirosaki University), Norio Matsumoto(Tectono-Hydrology Research Group, Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology (AIST)), Hidemi Tanaka(School of Science, The University of Tokyo), Chairperson:KOJI UMEDA(Hirosaki University), Chairperson:NAOJI KOIZUMI(School of Environmental Science,the University of Shiga Prefecture)

2:15 PM - 2:30 PM

[SCG75-03] Exploration of Tachikawa Fault by Groundwater Radon Concentration

*Fumiaki Tsunomori1, Tomoya Shimodate1 (1.Geochemical Research Center, Graduate School of Science, University of Tokyo)

Keywords:Radon, Groundwater, Tachikawa fault

We explored Tachikawa fault by use of groundwater radon concentration. Radon concentrations in shallow groundwater samples around the fault were comparable to that expected from the geology on the Kanto plane, and they were consistent with previous studies. Almost of all radon concentrations in deep groundwater from the bedrock-deep aquifer were also comparable to that in shallow groundwater. However radon concentrations in groundwater samples that were obtained at wells close to the fault were markedly higher than the expected radon concentration. This disparity can be explained by the existence of fracture zones spreading on both sides of the fault. The radon concentration distribution of deep groundwater samples suggests that a fault exists even at the southern part of the traditional line of Tachikawa fault.