Vector HTS-SQUID system for ULF magnetic field monitoring

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

*Corresponding author for this work

Research output: Contribution to journalConference articlepeer-review

3 Citations (Scopus)


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.

Original languageEnglish
Pages (from-to)763-766
Number of pages4
JournalIEEE Transactions on Applied Superconductivity
Issue number2 I
Publication statusPublished - 2003 Jun
Event2002 Applied Superconductivity Conference - Houston, TX, United States
Duration: 2002 Aug 42002 Aug 9


  • Earthquake
  • Long term monitoring
  • Magnetic field variation
  • Monitoring system
  • Ultra low frequency

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Electrical and Electronic Engineering


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