Vector HTS-SQUID system for ULF magnetic field monitoring

Author

Machitani, Y. ; Kasai, N. ; Fujinawa, Y. ; Iitaka, H. ; Shirai, N. ; Hatsukade, Y. ; Nomura, K. ; Sugiura, K. ; Ishiyama, A. ; Nemoto, T.

Author_Institution

Dept. of Electr., Waseda Univ., Tokyo, Japan

Volume

13

Issue

2

fYear

2003

fDate

6/1/2003 12:00:00 AM

Firstpage

763

Lastpage

766

Abstract

Anomalous magnetic field variations in the ultra low frequency (ULF) band were observed as precursory phenomena of earthquakes. We constructed a portable monitoring system by using HTS-SQUIDs for measuring the ULF environmental vector magnetic field. The operation of the system was verified at Mt. Bandai, an active volcano. The system safely worked over 100 hours on batteries. We have achieved long term monitoring with the system at the National Institute of Advanced Industrial Science and Technology (AIST) from February 7 to March 22 of 2002 using AC power. The measured magnetic field variations were compared with groundwater level, electric field and geo-electric pulse current variations measured at AIST in order to investigate the source of magnetic field radiation found during the long term monitoring.

Keywords

SQUID magnetometers; earthquakes; geomagnetic variations; geophysical equipment; high-temperature superconductors; magnetic field measurement; monitoring; portable instruments; volcanology; HTS SQUID magnetometer; Mount Bandai volcano; ULF environmental vector magnetic field monitoring; earthquake precursory phenomena; portable system; Battery charge measurement; Current measurement; Earthquakes; Electric variables measurement; Frequency; Magnetic field measurement; Magnetic fields; Monitoring; Pulse measurements; Seismic measurements;

fLanguage

English

Journal_Title

Applied Superconductivity, IEEE Transactions on

Publisher

ieee

ISSN

1051-8223

Type

jour

DOI

10.1109/TASC.2003.814054

Filename

1211715