HR: 0800h
AN: NG41A-0150    [Abstracts]
TI: Recent Progress in Electromagnetic (EM-) ACROSS in Tokai Region
AU: Nakajima, T
EM: nakajima.takahiro@jaea.go.jp
AF: Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan
AU: * Fujii, N
EM: snfujii@ipc.shizuoka.ac.jp
AF: Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan
AU: Sayanagi, K
EM: sayanagi@scc.u-tokai.ac.jp
AF: Tokai University, 3-20-1, Orido, Shimizu-ku, Shizuoka, 424-8610, Japan
AU: Nagao, T
EM: nagao@scc.u-tokai.ac.jp
AF: Tokai University, 3-20-1, Orido, Shimizu-ku, Shizuoka, 424-8610, Japan
AU: Kunitomo, T
EM: kunitomo.takahiro@jaea.go.jp
AF: Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan
AU: Hasada, Y
EM: hasada@seis.nagoya-u.ac.jp
AF: Nagoya University, Furo-Cho, Chikusa-ku, Nagoya, 464-8602, Japan
AU: Satomura, M
EM: semsato@ipc.shizuoka.ac.jp
AF: Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan
AU: Masuda, T
EM: setmasu@ipc.shizuoka.ac.jp
AF: Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan
AU: Kumazawa, M
EM: smkumaz@ipc.shizuoka.ac.jp
AF: Shizuoka University, 836 Ohya, Suruga-ku, Shizuoka, 422-8529, Japan
AB: A brief review is presented on the current state of the ACROSS (Accurately Controlled Routinely Operated Signal System), which has been developed for active monitoring of the physical states within the seismogenic zone for almost 10 years. An essential point of ACROSS is a noise-robust observation system of acquiring the transfer functions of both electromagnetic and seismic waves between a pair of signal source and receiver by means of accurately controlled continuous transmission of sinusoidal signals. The first generation experiments of EM (electromagnetic) ACR0SS are made successfully at Tono Geoscience Center (JAEA), Toki, Gifu prefecture. The signal source was a set of two electric dipoles of 150m-4A for transmission of a vector signal to obtain the tensor transfer function within a specified frequency range up to the distance of 50 km by data stacking. At present, two EM transmitters are being operated; one at Horonobe in Hokkaido with a set of electric dipoles of 180m-10A continuously for more than 2 years, and another at Shizuoka with a larger dipole moment of 600m-20A for long distance transmission. We will report the recent results obtained by Shizuoka transmission experiments to determine the transfer functions and to estimate the delay time of signal propagation up to about 20km distant electric potential and magnetic field observation sites. Further we present a prospect towards the monitoring of effects of water in the anticipated Tokai Earthquake focal region located beneath the Shizuoka prefecture. As a matter of course, we need more powerful transmitters and also an observation network designed specially for our approach.
DE: 0903 Computational methods: potential fields (1214)
DE: 0925 Magnetic and electrical methods (5109)
DE: 8108 Continental tectonics: compressional
DE: 8123 Dynamics: seismotectonics
SC: Nonlinear Geophysics [NG]
MN: 2007 Fall Meeting