| 講演要旨(和文) | | 高レベル放射性廃棄物の地層処分場候補地選定では、調査地区が沿岸域となった場合は適用できる物理探査手法が限られてくる。そのため、筆者らは、このような高レベル放射性地層処分事業で想定される調査地域において課題とされる沿岸海域での電磁法探査手法の確立の一環として、海底電磁探査法の機器製作を進めてきた。本稿では、沿岸海域で測定上の問題となる波浪の動きに伴い発生する電磁ノイズに関して、実測試験を実施して検討を行い、0.1Hz周辺で卓越するノイズの存在を明らかにするとともに、沿岸域の浅海底で波浪の影響を最小限に抑えるために開発された、低床型でかつ浮上用のブイを取り去ってアンカードブイ方式を採用した新型のスタンドアローン型受信器と、浮上ブイを持つ既存型受信器での海深15m〜27mでの比較を実施した結果、新型受信器において、0.1Hz周辺の卓越したノイズに対する改善効果が確認された。 |
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| | 講演要旨(英文) | | For the site selection of high-level radioactive waste geologic repository around the coastal area survey, the geophysical exploration methods that can be applied are limited. Therefore, the authors have developed the marine EM receiver system as part of the seabed electromagnetic exploration method which is important issue in the coastal area of electromagnetic survey for high-level radioactive waste geologic repository project. This article, regarding to electromagnetic noise problems for measurement in accordance with the movement of tidal waves in the coastal area survey, a test survey has been conducted and found out 0.1 Hz band noise by the effect of tidal waves. To apply Electromagnetic exploration method for the coastal area in shallow water depth, new system that had improved to minimize the impact of tidal waves movement by the lower-floor shape of the casing with anchored buoy, and the existing system with topping buoy type receiver have been compared in the test at water depth of 15 meters to 27 meters. As a result of this test, 0.1 Hz band noise in new system has been improved. |
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