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Tsuruga, Kayoko; Kunitomo, Takahiro; Hasada, Yoko; Kumazawa, Mineo; Shigeta, Naotaka; Kasahara, Junzo
IWAM04, 116 Pages, 2004/08
We are developing an active seismic monitoring methodology on the seismic ACROSS to detect any subtle change of geophysical properties in the Earth's crust. To demonstrate the availability of the seismic ACROSS, which uses coherent seismic waves actively, it may be the best to use several dense arrays routinely. In this study, we briefly review our seismic array observation system by the seismic ACROSS and their specifications, and report the latest results of array observation.
JNC, 1)*; Niizato, Tadafumi; Aoki, Kazuhiro; ;
International workshop on "Active Monitoring in the Solid Earth Geophysics", 0 Pages, 2004/07
Japan Nuclear Cycle Development Institute (JNC) is developing a remote monitoring system using seismic and electromagnetic ACROSS (Accurately Controlled Routinely Operated Signal System) in the Horonobe Underground Research Laboratory (URL). The Horonobe URL project is devoted to the technological development for a safe geological disposal of high level radioactive wastes over a 20-year period from March 2001 in Horonobe-cho in northern Hokkaido, Japan. The purpose of installing a remote monitoring system is to monitor changes in the geological environment before, during and after the construction of an URL facility. The source and receiver system of electromagnetic ACROSS and the receivers of a seismic ACROSS will be installed in the fiscal year 2004, while the source of the seismic ACROSS will be transported from Tono Geoscience Center in 2005.
Tsukui, Rota; Niizato, Tadafumi; Aoki, Kazuhiro; Fukushima, Tatsuo
Proceedings of 1st International Workshop on Active Monitoring in the Solid Earth Geophysics (IWAM 2004), 0 Pages, 2004/07
Japan Nuclear Cycle Development Institute (JNC) is developing a remote monitoring system using seismic and electromagnetic ACROSS (Accurately Controlled Routinely Operated Signal System) in the Horonobe Underground Research Laboratory (URL). Horonobe URL is devoting to the technology development for the safe geological disposal of high level radioactive wastes over 20 years. The project has been operating since March 2001 in Horonobe-cho, northern Hokkaido, Japan. The target of a remote monitoring system is to monitor the change of geological environment before, during and after the construction of the URL underground facility. Receiver system of seismic ACROSS and source and receiver system of electromagnetic ACROSS will be installed in 2004 fiscal year, while source of seismic ACROSS will be transported from Tono Geoscience Center in 2005.
Nakajima, Takahiro; Kunitomo, Takahiro; Nagao, Hiromichi; Kumazawa, Mineo; Shigeta, Naotaka
International Workshop on Active Monitorig 2004, p.148 - 151, 2004/00
We have developed and tested a new electromagnetic sounding method, which is called EM-ACROSS (ElectroMagnetic - Accurately Controlled Routinely Operated Signal System). This system is designed for the survey below 500 Hz. We carried out a field test using this system at Tono area, and acquired very accurate transfer function between the source and receiver which the distance is about 700 m. From the phase of the transfer function for a month, we can see the correlation with the rainfall.
Nakajima, Takahiro; Kumazawa, Mineo; Shigeta, Naotaka; Kunitomo, Takahiro; Nagao, Hiromichi; Matsumoto, Hiroshi*
International Workshop on Active Monitoring 2004, p.100 - 103, 2004/00
We introduce a new observation system named EM-ACROSS (Electro-Magnetic Accurately Controlled Routinely Operated Signal System) for a monitoring the electrical state in the ground. Electromagnetic field has different feature from seismic wave, in a sense that electromagnetic field behaves not only as waves but also diffusion. We describe the overview of EM-ACROSS and the progress of its development at Tono Geoscience Center. We also note the possibility of the active monitoring of the crust using electromagnetic field.