Preseismic Electromagnetic Phenomena―A Time Scale of Stress Stimulated Charges―

カテゴリ: 論文誌(論文単位)

グループ名: 【A】基礎・材料・共通部門

発行日: 2016/05/01

タイトル(英語): Preseismic Electromagnetic Phenomena―A Time Scale of Stress Stimulated Charges―

著者名: Chihiro Yamanaka (Planetary Science Lab., Osaka University), Hiroshi Matsumoto (Planetary Science Lab., Osaka University), Hiroshi Asahara (Planetary Science Lab., Osaka University)

著者名(英語): Chihiro Yamanaka (Planetary Science Lab., Osaka University), Hiroshi Matsumoto (Planetary Science Lab., Osaka University), Hiroshi Asahara (Planetary Science Lab., Osaka University)

キーワード: stress stimulated charges，seismoelectric phenomena，frequency dependence

要約(英語): In order to verify the seismo-electric phenomena before large earthquakes (EQs), stress-stimulated charges (SSCs) in the lithosphere were assumed and the frequency characteristic was evaluated for the electromagnetic field caused by the SSCs, considering a charge generation coefficient and resistivity in crust. Time variation of SSCs was dependent on the stress-changing rate and the degree of dielectric relaxation. Possible electromagnetic spectra due to apparent charges were obtained by the linear system analysis. Because of the low resistivity in ordinary crust, SSCs after a short stress-changing event were quickly recombined and would not contribute much to EQ precursor phenomena. On the other hand, preseismic seismo-electric phenomena such as GPSTEC anomalies are known to last as long as 40 minutes. In order to achieve such long lasting electromagnetic phenomena before an EQ, the resistivity of the interested area should be enough high or the stress changing in crust should last continuously enough long. We can also assume continual stress-changing events at multi-spots around the fault zone which lasting several tens of minutes before large EQs.

本誌: 電気学会論文誌A（基礎・材料・共通部門誌） Vol.136 No.5 （2016） 特集：電磁界を用いた自然災害軽減のための観測・予測・解析技術

本誌掲載ページ: 310-314 p

原稿種別: 論文／英語

電子版へのリンク: https://www.jstage.jst.go.jp/article/ieejfms/136/5/136_310/_article/-char/ja/