HR: 1340h
AN: S33B-1094    [Abstracts]
TI: Detection of the Temporal Variations of Structure Sensitive Bodies by the Active Monitoring
AU: * FUJII, N
EM: fujii@seis.nagoya-u.ac.jp
AF: RCSVD, Nagoya University, Furo-cho, Chikusa-ku,, Nagoya, 464-8602 Japan
AU: KUMAZAWA, M
EM: mkz@tono.jnc.go.jp
AF: TGC, Japan Nuclear Cycle Development Institute, Akeyo-cho,, Mizunami, 509-6132 Japan
AB: Observable phenomena that cause temporal variations of stress field related to generations of earthquakes and volcanic eruptions could be mainly the reflected wave from scattering sources. The heterogeneity in the lithosphere originated from both stress state and heterogeneous distribution of fluid-bearing rocks can be the scattering sources. Temporal variations of the scattering sources due to the structure sensitivity of rocks are essential characteristics of seismogenic regions as well as the active volcanic regions. The active geophysical monitoring would be the essential tool to detect and clarify such an evolving process that governed by the structure sensitivity of rocks in the crust and upper mantle. Among many structure sensitive phenomena, probable changes in the reflected seismic or electromagnetic signals are expected in the temporal variations of impedance and anisotropic dispersion of the transmitted signals in the subduction zone where the scattering sources are evolving associated with the movement of the fluid mainly composed of supercritical water in the crust and upper mantle conditions. Recently discovered slow slip events and deep non-volcanic tremors in the subduction zone could be one of the most challenging targets to clarify their characteristics by using the active monitoring techniques.
DE: 7230 Seismicity and seismotectonics
DE: 8159 Rheology--crust and lithosphere
DE: 8164 Stresses--crust and lithosphere
DE: 8168 Stresses--general
DE: 1734 Seismology
SC: Seismology [S]
MN: 2004 AGU Fall Meeting