Exploration of the shallow electrical conductivity structure below seafloor by using the ocean dynamo effect

2015 Fiscal Year Final Research Report

• Project/Area Number: 25610136
• Research Category: Grant-in-Aid for Challenging Exploratory Research
• Allocation Type: Multi-year Fund
• Research Field: Solid earth and planetary physics
• Research Institution: Japan Agency for Marine-Earth Science and Technology
• Principal Investigator: HAMANO Yozo 国立研究開発法人海洋研究開発機構, 地球深部ダイナミクス研究分野, 特任上席研究員 (90011709)
• Co-Investigator(Kenkyū-buntansha): SUGIOKA Hiroko 神戸大学, 理学研究科, 准教授 (00359184) ; TADA Noriko 国立研究開発法人海洋研究開発機構, 地球深部ダイナミクス研究分野, 技術研究員 (00509713)
• Project Period (FY): 2013-04-01 – 2016-03-31
• Keywords: 海底電磁気観測 / 電気伝導度 / 電磁気構造探査 / 海洋ダイナモ効果 / 津波

Outline of Final Research Achievements

Based on the theoretical formulation of the ocean dynamo effect, in which ocean currents in the earth’s magnetic field generate the variations of electric and magnetic fields due to the motional induction, we developed a new method for probing the electrical conductivity structure under the seafloor from the seafloor observations of the variations of the electromagnetic filed and pressure change due to ocean currents. Applying the method to the observed data sets, we demonstrated the possibility of estimating the conductivity structure below seafloor by using the signals generated by tsunamis and estimated the application limit of the present method.

Free Research Field

地球惑星内部物理学