A research of mechanism of electromagnetic radiation associated with crustal activities

与地壳活动相关的电磁辐射机制研究

• 批准号: 02640308
• 负责人: TABEI Takao
• 金额: $ 1.34万
• 依托单位: Kochi University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02640308/
• 关键词: Crustal Activities; Electromagnetic Radiation; ELF; VLF; Electromagnetic Noise; 地震予知

Main purpose of this study is to clarify characteristics of electromagnetic radiation associated with earth's crustal activities in order to search for a new technique for prediction of earthquake or volcanic eruption. We analyzed continuous records of natural electromagnetic noises in ELF/VLF bands that had been obtained through cooperative observation using ELF/VLF Radiometer conducted by Kochi University and Stanford University, U. S. A., since 1985.We first investigated relationship between anomalous electromagnetic noises and major earthquakes and volcanic eruptions occurred in and around Japan during the past 5 years. Though clear precursory electromagnetic radiation was not detected, anomalous abrupt change of noise level was sometimes observed synchronously with the ground motion of felt earthquake. Unfortunately, it became clear that sufficient information about propagation direction and characteristics of the electromagnetic waves had not been recorded in the present recordin … More g system of the Radiometer because of the limit of recording capacity. To compensate for it we made a continuous recording system for ELF waves using Digital Audio Tape with a large recording capacity. Moreover, we developed a ball antenna system of noncontact type designed for observing three components of electric field using large stainless spheres and made preliminary experiments in a laboratory, field, and shallow sea bottom.Secondly, we executed many kinds of numerical simulations in analyses of background electromagnetic pulse waves in whistler and waveguide modes and then compared with the observed waves. Especially, theoretical interpretations on propagation mechanism of electromagnetic waves in the ionosphere and its time variation were advanced. Moreover, we investigated relationship between electromagnetic pulse wave observed at Kochi and lightening activity at northern Australia that is located at a geomagnetically conjugate point against Kochi.Finally, we summarized above research results as a Report of Research Project, Grant-in-Aid for Scientific Research. Less

本研究的主要目的是澄清与地壳活动有关的电磁辐射特征，以期寻求地震或火山喷发预报的新技术。本文分析了1985年以来美国高知大学和斯坦福大学联合使用ELF/VLF辐射计进行合作观测获得的ELF/VLF波段自然电磁噪声的连续记录。本文首先研究了近5年来日本及其周边地区发生的大地震和火山爆发与异常电磁噪声的关系。虽然没有探测到明显的前兆电磁辐射，但有时会观测到噪声级的异常突变与有感地震的地面运动同步。不幸的是，由于记录容量的限制，目前的辐射计记录系统没有记录电磁波的传播方向和特性的足够信息。为了弥补这一缺陷，我们利用大容量的数字磁带制作了一套低频波连续录音系统。此外，我们开发了一种非接触式球天线系统，设计了一种大型不锈钢球，用于观测三种分量的电场，并在实验室、野外和浅海底进行了初步实验。其次，对哨声模式和波导模式下的背景电磁脉冲波进行了多种数值模拟分析，并与观测波进行了比较。特别是对电磁波在电离层中的传播机理及其时变进行了理论解释。此外，我们还研究了在高知观测到的电磁脉冲波与位于高知地磁共轭点的澳大利亚北部闪电活动之间的关系。最后，我们将上述研究成果总结为《科研资助项目报告》。少

项目成果

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Kusunose,M.et al.：“与空气阵雨相关的无线电信号。”

Sasaki,H.,A.Sato,H.Kobayashi,M.Kusanose,T.Tabei,T.Ogawa,T.Yanagita,T.Saito,K.Yamamoto: "Preliminary observation of ELF waves in the sea for the research of nuclearites." Proc.21st Int.Cosmic Ray Conf.,Dublin,Ireland. (1991)

Sasaki,H.,A.Sato,H.Kobayashi,M.Kusanose,T.Tabei,T.Okawa,T.Yanagita,T.Saito,K.Yamamoto：“海洋中 ELF 波的初步观测，用于研究

木村 昌三,岡野 健之助: "四国地方の下部地殻とモホロヴィチッチ不連続面" 高知大学学術研究報告(自然科学). 40. 49-61 (1991)

Shozo Kimura、Kennosuke Okano：“四国地区的下地壳和莫霍罗维奇不连续面”高知大学学术研究报告（自然科学）40. 49-61（1991）。

Sasaki,H.et al.: "Preliminary observation of ELF waves in the sea for the research of nuclearites." Proc.21st Int.Cosmic.Ray Conf.,Dublin,Ireland.(1991)

Sasaki,H.et al.：“对海中 ELF 波进行初步观察，以研究核子。”

Tabei, T. et al.: "GPS measurements in Shikoku region, Southwest Japan : Initial results from 1990 to 1991 (in Japanese)." Zisin (J. Seism. Soc. Japan). 44. 315-324 (1991)

Tabei, T. 等人：“日本西南部四国地区的 GPS 测量：1990 年至 1991 年的初步结果（日语）。”