High Sensitive Geomagnetic Field Observation at the Area where Induced Earthquakes feequently occur by the 3.11 Tohoku Earthquake

2014 Fiscal Year Final Research Report

• Project/Area Number: 24560507
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Research Field: Measurement engineering
• Research Institution: Tohoku University
• Principal Investigator: TAKEUCHI Nobunao 東北大学, 理学(系)研究科(研究院), 客員研究者 (80005420)
• Co-Investigator(Kenkyū-buntansha): OKUBO Kan 首都大学東京, 大学院システムデザイン研究科, 准教授 (90336446) ; ISOGMI Shinji 福島工業高等専門学校, 一般教科, 准教授 (10586853)
• Project Period (FY): 2012-04-01 – 2015-03-31
• Keywords: 地震極微小磁気変化 / 高温超電導SQUID磁力計 / 地震断層運動 / 地磁気連続観測 / 3.11東北大地震

Outline of Final Research Achievements

We successfully observed “co-faulting” geomagnetic field changes due to piezomagnetic effects caused by earthquake rupturing in 2008 Iwate-Miyagi Nairiku earthquake of M7.2 using the flux-gate magnetometers. This observed geomagnetic variation signal accompanying earthquake fault movement is very small, approximately several hundred pico-tesla.
Since March 2012 we have performed long-term high sensitive geomagnetic observations using high-temperature superconducting-quantum-interference-device (HTS-SQUID) magnetometer system Unit1 at Iwaki observation site in Fukushima, Japan. Additionally, since October 2014, we have also introduced the new HTS- SQUID magnetometer system Unit2. A high-resolution accelerometer is also installed at observation point. At a result, we successfully observed the geomagnetic field change signal associated with the earthquake of M5.9 (on September 20, 2013) using our high-sensitive magnetometer Unit1 system.

Free Research Field

地震電磁気学