HR: 0800h
AN: T51B-0451    [Abstracts]
TI: Some recent observational results on seismogenic ULF emissions.
AU: * Hayakawa, M
EM: hayakawa@whister.ee.uec.ac.jp
AF: University of Electro-Communications, 1-5-1 Chofugaoka Chofu, Tokyo, 182-8585 Japan
AU: Hattori, K
EM: hattori@earth.s.chiba-u.ac.jp
AF: Chiba University, 1-33 Yayoicho Inage-ku,, Chiba, 263-8522 Japan
AU: Gotoh, K
EM: k_gotoh@nict.gp.jp
AF: NICT, 3-4 Hikarinooka, Yokosuka, 239-0847 Japan
AU: Ida, Y
EM: ida@whistler.ee.uec.ac.jp
AF: University of Electro-Communications, 1-5-1 Chofugaoka Chofu, Tokyo, 182-8585 Japan
AB: It is known that electromagnetic emissions take place in association with earthquakes in a wide frequency range from DC/ULF to VHF. But the most promising frequency range from the standpoint of short-term earthquake prediction is ULF (ultra-low-frequency, f<10Hz), because those ULF emissions are definite to have come from the focal zone. While, the generation mechanisms of higher frequency seismogenic emissions are extremely poorly understood. We show our latest results on seismogenis ULF emissions. The first one is the principal component analysis (PCA) for the ULF emissions associated with the Izu islands earthquake swarm in July 2000. Then, the second will be the fractal (mono-and multi-) analysis for the Guam earthquake. These sophisticated signal processing would be of great importance in elucidating precursory weak seismogenic ULF emissions.
DE: 6969 Remote sensing
DE: 6994 Instruments and techniques
DE: 7218 Lithosphere and upper mantle
DE: 1512 Environmental magnetism
DE: 0604 Antenna arrays
SC: Tectonophysics [T]
MN: 2004 AGU Fall Meeting