Journal of the Korean earth science society (한국지구과학회지)

The Korean Earth Science Society (한국지구과학회)
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A Preliminary Study on Micro-earthquakes Occurred from 2010 to 2017 in Busan, Korea

2010-2017년 부산지역의 미소 지진 예비 탐색

  • Yoon, Soheon (Department of Geological Sciences, Pusan National University) ;
  • Han, Jongwon (Department of Geological Sciences, Pusan National University) ;
  • Won, Deokhee (Coastal & Ocean Engineering Division, Korea Institute of Ocean Science & Technology) ;
  • Kang, Su Young (Institute of Geological Hazard and Industrial Resources, Pusan National University) ;
  • Ryoo, Yong Gyu (Cheongju Branch Office of Meteorology) ;
  • Kim, Kwang-Hee (Department of Geological Sciences, Pusan National University)
  • 윤소헌 (부산대학교 지질환경과학과) ;
  • 한종원 (부산대학교 지질환경과학과) ;
  • 원덕희 (한국해양과학기술원 해양공학연구본부) ;
  • 강수영 (부산대학교 지질재해산업자원연구소) ;
  • 유용규 (청주기상지청) ;
  • 김광희 (부산대학교 지질환경과학과)
  • Received : 2019.03.23
  • Accepted : 2019.05.28
  • Published : 2019.06.30
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Abstract

Although the knowledge of current seismicity is a critical information for making and implementing effective earthquake-related policy, the detailed seismicity information of the metropolitan areas with high-population density has been largely underestimated due to the high-level of cultural noise and small earthquake magnitude. This study presents 12 earthquakes including 2 earthquakes previously known and 10 additional earthquakes occurred from 2010 to 2017 in Busan, but they were unreported by the Korea Meteorological Administration. Matched filter technique is used to detect micro-earthquakes. Although the epicenters of micro-earthquakes though present a distinguished linearity, a correlation with faults in the area is unknown. A repeated micro-seismicity suggests that there are subsurface structures responsible for observed events. If large earthquakes occur along the fault in Busan, they may cause catastrophic natural disasters. Given the fact that the recent earthquakes did not accompany any surface signatures, it is highly recommended that the current micro-seismicity be investigated, and updated seismicity information be incorporated into establishing active fault maps in Korea.

지진 관련 정책 입안과 수행에 우선적으로 고려되어야 할 정보가 지진 발생현황이지만, 대도시와 인구밀집 지역의 경우 높은 생활잡음으로 인해 작은 규모의 지진 발생을 정확히 인지하지 못하는 경우가 많다. 본 연구에서는 2010년부터 2017년까지 부산지역에서 발생했지만, 규모가 작아 기상청 지진목록에 수록되지 않은 미소 지진 10회를 파형의 유사성을 이용하여 검출하였고, 기존에 발생사실을 알고 있던 지진을 포함하여 총 12회의 지진을 분석에 사용하였다. 새로이 보고되는 지진은 선형을 보이면서 발생하고 있지만, 주변의 단층과 직접적으로 연관하여 해석하기에는 자료가 충분치 않다. 규모가 작은 미소 지진이 꾸준히 발생한다는 것은 지하에 지진을 일으키는 단층이 존재함을 시사하고, 부산과 같은 인구밀집 지역에서 과거 피해를 유발한 역사지진과 비슷한 규모의 지진이 발생한다면 대형 피해로 발전될 가능성이 매우 크다. 최근 우리나라에서 발생한 피해 유발 지진이 지표파열을 동반하지 않고 발생하고 있음을 고려할 때 현재 발생하고 있는 미소 지진 현황을 파악하여 지표 단층조사와 함께 지하단층을 규명하는데 활용하여야 한다.

Keywords

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