日本地球惑星科学連合2014年大会

講演情報

ポスター発表

セッション記号 S (固体地球科学) » S-EM 固体地球電磁気学

[S-EM36_30PO1] 電気伝導度・地殻活動電磁気学

2014年4月30日(水) 18:15 〜 19:30 3階ポスター会場 (3F)

コンビーナ:*山崎 健一(京都大学防災研究所)、多田 訓子(海洋研究開発機構)

18:15 〜 19:30

[SEM36-P09] 津波早期警戒のための陸上地磁気三成分観測点

*川嶋 一生1藤 浩明2吉村 令慧3藤井 郁子4仰木 淳平4阿部 聡5 (1.京都大学大学院理学研究科、2.京都大学大学院理学研究科附属地磁気世界資料解析センター、3.京都大学防災研究所地震防災研究部門、4.気象庁地磁気観測所、5.国土地理院)

キーワード:地磁気, 津波

Conductive sea water moving in the geomagnetic main field generates electromagnetic variations by a physical process called the oceanic dynamo effect. This effect at the time of tsunami passages was recently detected on the seafloor in the northwest Pacific (Toh et al., 2011) and on Easter Island (Manoj et al., 2011). The tsunami-induced electromagnetic field is expected to contribute to existing global tsunami warning systems.
We are carrying out a project that aims to observe geomagnetic variations associated with tsunami passages by ground-based real-time observations. This project requires a pair of geomagnetic observation sites for clear detection of tsunami events. The geomagnetic coast effect and the external field due to ionospheric and/or magnetospheric disturbances can be removed by taking real-time differences between a coastal and an inland geomagnetic sites. We installed a vector magnetometer at Umaji located in the middle of Muroto Peninsula, where artificial electromagnetic noises are very small. This location is selected as a counterpart of the existing observation site at Muroto located at the tip of the peninsula, which is operated by Geospatial Information Authority of Japan (GSI).
In this presentation, we will make a progress report on our ground-based tsunami warning system consisting of a pair of vector magnetometers. This system is intended to detect the geomagnetic field variations induced by tsunamis at the time of Nankai/Tonankai earthquakes.