| Presentation | 1995/7/27 Results of ultra-low-frequency magnetic field measurements during the Guam earthquake of 8 August 1993 Ryusuke Kawate, Masashi Hayakawa, Oleg A. Molchanov, |
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| Abstract(in Japanese) | (See Japanese page) |
| Abstract(in English) | We report the results of measurements of ultra-low-frequency magnetic noise during a large earthquake (Ms=7.1) at Guam of 8 August, 1993 (depth～60km). The ULF observing system is located in the Guam island, about 65km from the epicenter. Several distinct features of this analysis are summarized. (1)We have proposed rather sophisticated statistical analyses (monthly mean, standard deviation) in order to estimate the wave intensity and polarization (i.e. ratio Z/H). (2)A comparison between the ULF wave activity and ΣKp, is useful in distinguishing between the space geomagnetic pulsations and non-space emissions. (3)Then, the use of the ratio (Z/H) is found to be of essential importance in discrimating the emissions presumably of seismic origin from space plasma waves. (4)The statistical analysis of the temporal evolution of this ratio, has yielded that it shows a broad maximum only about one month before the earthquake, and this suggests that the emissions during this period are very likely to be magnetic precursors. (5)The temporal variation of Z component is similar to that for the Loma Prieta earthquake such that it shows a broad maximum ten days ～ two weeks before the earthquake and another increase a few days before the earthquake. (6)The emissions presumably associated with the earthquake are of noise-like nature, and their main frequency is 0.02～0.05 Hz (with maximum intensity ～ 0.1nT). |
| Keyword(in Japanese) | (See Japanese page) |
| Keyword(in English) | Guam earthquake / ULF seismogenic emission / Earthquake prediction |
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| Committee | SANE |
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| Conference Date | 1995/7/27(1days) |
| Place (in Japanese) | (See Japanese page) |
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| Topics (in Japanese) | (See Japanese page) |
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| Registration To | Space, Aeronautical and Navigational Electronics (SANE) |
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| Language | ENG |
| Title (in Japanese) | (See Japanese page) |
| Sub Title (in Japanese) | (See Japanese page) |
| Title (in English) | Results of ultra-low-frequency magnetic field measurements during the Guam earthquake of 8 August 1993 |
| Sub Title (in English) | |
| Keyword(1) | Guam earthquake |
| Keyword(2) | ULF seismogenic emission |
| Keyword(3) | Earthquake prediction |
| 1st Author's Name | Ryusuke Kawate |
| 1st Author's Affiliation | Department of Electronic Engineering, The University of Electro-Communications() |
| 2nd Author's Name | Masashi Hayakawa |
| 2nd Author's Affiliation | Department of Electronic Engineering, The University of Electro-Communications |
| 3rd Author's Name | Oleg A. Molchanov |
| 3rd Author's Affiliation | Department of Electronic Engineering, The University of Electro-Communications |
| Date | 1995/7/27 |
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| Volume (vol) | vol.95 |
| Number (no) | 190 |
| Page | pp.pp.- |
| #Pages | 8 |
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