Geophysics and Geophysical Exploration (지구물리와물리탐사)

Korean Society of Earth and Exploration Geophysicists (한국지구물리·물리탐사학회)
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A Study on the Possibility of the Earthquake Detection based on Telluric Current Monitoring

지전류 모니터링 기반 지진 감지 가능성 연구

  • Received : 2019.06.15
  • Accepted : 2019.08.01
  • Published : 2019.08.31
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Abstract

Recently, since earthquakes have happened frequently in Gyeongju and Pohang areas in Korea, the earthquake detection research gets lots of attention. Geophysical monitoring data have been changed during the earthquake activity because the huge amount of energy is accumulated. The change of telluric current can be predicted by both of piezoelectric and electrokinetic effects before or during the earthquake occurrence, and if the change value exceeds the conventional telluric current noise, we can measure changes in the electric field associated with earthquakes. In this study, we have self-developed and verified the system that can monitor the telluric current. In order to verify our telluric current monitoring system, we installed lines of 40 m (E-W direction) and 28 m (N-S direction) on the site in Pohang. The telluric currents were sampled at 1 kHz for about a month. We have compared and analyzed the data of earthquake signals and electrical noises based on the earthquakes that occurred during the monitoring period. We have monitored if there were significant signals related to the earthquake on measured time series data. Through this study, we will suggest the direction of continuous research in the future.

최근 발생하는 경주 및 포항 일대의 지진으로 지진 감지 연구의 중요성이 높아지고 있다. 보통 지진 활동 과정에서 막대한 양의 에너지가 축적되므로 지구물리학적 관측 값의 변화가 발생한다. 지진발생 전 혹은 동시에 압전 효과(piezoelectric effect) 및 동전기 효과(electrokinetic effect) 등에 의해 지전류의 변화가 예상 가능하며, 이러한 변화치가 통상적인 지전류 잡음수준을 넘어서는 크기로 발생된다면, 지진과 관련된 전기장의 변화를 측정가능하게 된다. 본 연구에서는 지전류를 상시 모니터링 할 수 있는 지전류 모니터링 시스템을 자체 개발하고 현장 검증하였다. 지전류 모니터링 시스템의 현장 검증을 위해 포항시 일대에서 동서 방향 40 m, 남북 방향 28 m로 측선을 설치하였다. 약 1개월간 1 kHz 샘플링의 지전류 데이터를 모니터링 하였고, 관측 기간 동안 발생한 국내 지진을 토대로 지진 신호(signal)와 주변 전기적 잡음(noise)의 자료 처리를 통해 비교 분석하였다. 측정된 시계열 자료로부터 지진과 관련된 유의미한 신호가 포착되는지 검토하였으며, 본 연구를 통해 향후 지속적인 연구의 방향을 제시하고자 한다.

Keywords

References

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