JpGU-AGU Joint Meeting 2017

Presentation information

[JJ] Poster

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

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

Sun. May 21, 2017 5:15 PM - 6:30 PM Poster Hall (International Exhibition Hall HALL7)

[SCG75-P03] Changes in permeability in the Hirabayashi well estimated by long-term groundwater-level observation

*Norio Matsumoto1, Tsutomu Sato1, Akinobu Miyakoshi1 (1.Geological Survey of Japan, National Institute of Advanced Industrial Science and Technology (AIST))

Keywords:permeability, groundwater level, pumping test

The Hirabayashi well encountered the Nojima fault at the depth of 623.1 - 625.3 m, and we have been observing groundwater level until now. The groundwater-level observation shows that estimated permeability was constant between 1996 and 2006, then slightly decreased, and suddenly increased after the 2011 Tohoku-oki and the 2013 Awaji-island earthquakes. Pumping tests are carried out on 1996, 2000 and 2016. Permeability estimated by the three pumping tests is consistent with that estimated by groundwater-level observation. The temperature logging just after the 2016 pumping test indicates that main aquifer is not at the depth of 630 - 650m where the casing of the well was perforated, but is shallower than at the depth of 200 m.