[S-EM16] 電気伝導度・地殻活動電磁気学

[SEM16-P05] Wideband Magnetotelluric and Magnetic Surveys across the Tendaho Graben in the Afar Depression, Ethiopia

*吉村 令慧¹、石川 尚人²、Tesfaye Kidane³、加々島 慎一⁴、望月 伸竜⁵、A. Muluneh Ameha³、北川 桐香⁴ (1.京都大学防災研究所、2.京都大学大学院人間・環境学研究科、3.アディス・アベバ大学、4.山形大学理学部、5.熊本大学大学院先導機構)

キーワード：エチオピア・アファール凹地、地磁気地電流探査、磁気探査

The Afar area (Ethiopia) is well known as one of continental rifts transitioning to oceanic spreading centers. In order to delineate subsurface electric properties and document an initial stage of the formation process of magnetic stripes, we carried out wideband magnetotelluric (MT) measurements and ground magnetic survey along a common profile in 2016 and 2017. This profile, approximately 55km long, cuts across the Tendaho Graben in the Afar Depression. In MT survey, we obtained electromagnetic and electric data at 14 sites using MTU-5A (Phoenix Geophysics) and ELOG1K-PHX (NT system design) systems. In magnetic survey on foot, we recorded total magnetic fields at 2.4 meters above the ground every 4 seconds by utilizing GSM-19 Overhauser magnetometer (GEM systems). In this presentation, we will introduce the outline of our project and show preliminary results of MT and magnetic surveys.