Journal of the Korean earth science society (한국지구과학회지)

The Korean Earth Science Society (한국지구과학회)
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Determining the Orientation of Accelerograph Stations in South Korea using Ambient Noise Data

배경잡음 자료를 이용한 국내 가속도 관측망의 방위각 보정값 측정

  • Lee, Sang-Jun (The Institute of Basic Science, Korea University)
  • 이상준 (고려대학교 기초과학연구원)
  • Received : 2021.03.11
  • Accepted : 2021.04.14
  • Published : 2021.04.30
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Abstract

Orientation corrections for the total of 268 accelerograph stations of the Korea Meteorological Administration (KMA) were estimated using ambient noise cross-correlation. As this method uses ambient noise data instead of teleseismic waveforms from earthquakes under certain conditions, reliable orientation corrections can be obtained using only two-month long continuous seismic data from dense seismic networks in the Korean peninsula.Three-component continuous data recorded at the 268 accelerograph stations from January to February 2020 were used to estimate orientation corrections. The results are comparable to the previous results obtained from teleseismic waveforms; the overall standard deviations of the orientation corrections are less than 5°. Therefore, orientation corrections for the accelerograph station network can be tracked periodically by the ambient-noise method and the result can be used in various studies using the horizontal-component of acceleration data.

기상청에서 운용하는 268개의 가속도 관측망에 대한 방위각 보정값을 측정하기 위해 배경잡음 교차상관 방법을 사용하였다. 이 방법은 배경잡음 자료를 사용하기 때문에 원거리 지진자료를 사용하는 방법과 달리 특정 조건에 맞는 지진을 선정할 필요가 없고, 한반도와 같은 조밀한 관측망에 적용하여 단기간의 연속 파형 자료만을 사용해 신뢰할 수 있는 방위각 보정값을 측정할 수 있다. 계산에는 2020년 1월부터 2020년 2월까지 총 268개의 기상청 가속도 관측망에 기록된 3성분 연속 파형 자료를 사용했다. 계산된 결과를 보면 기존에 원거리 지진자료를 사용한 결과와 매우 유사하며, 기존 결과에서 누락된 가속도 관측소들을 포함한 대부분 관측소의 방위각 보정 계산 결과가 표준편차 5° 이하로 안정적으로 계산되는 것을 확인할 수 있다. 따라서 본 연구를에서 사용한 방법을 활용해 기상청 가속도 관측소에 대한 방위각 보정값을 지속적으로 모니터링하고 측정된 결과를 활용하면, 가속도 자료의 수평 성분을 활용한 다양한 연구들에 활용할 수 있을 것이다.

Keywords

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