12:15 PM - 12:30 PM
[SEM33-12] A Comparison Evaluation of Geomagnetic Observation Signal Using HTS-SQUID Magnetometers at Iwaki Observation Site
Keywords:HTS-SQUID Magnetometer, Geomagnetic Observation, earthquake piezomagnetic effect
Our research group reported successful observation of "co-faulting" Earth's magnetic field changes, whose sources are the earthquake piezomagnetic effects, in 2008 Iwate-Miyagi Nairiku earthquake of M7.2 (2011 Okubo et al.). Then, an important finding is that the geomagnetic variation signal accompanying fault movement is very small; therefore development of a high-sensitive magnetometer system is very significant.
To solve this problem, since March 2012 we have introduced long-term precise geomagnetic observations using high-temperature-superconductor based superconducting-quantum-interference-device (HTS-SQUID) magnetometer system Unit No.1 (mark I) at Iwaki observation site (IWK) in Fukushima, Japan. The observation clock has been synchronized by use of GPS signals. An high-resolution accelerometer is also installed at observation point.
Moreover, since October 2014, we have also introduced the new HTS- SQUID magnetometer system Unit No.2 (mark II). In this study, we make a comparison evaluation of the geomagnetic field observation systems, and then we estimate the performance of our HTS-SQUID magnetometer systems for geomagnetic observation.