한국지구과학회지 (Journal of the Korean earth science society)

  • 제39권4호
  • /
  • Pages.342-348
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  • 2018
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  • 1225-6692(pISSN)
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  • 2287-4518(eISSN)
한국지구과학회 (The Korean Earth Science Society)
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Temporal and Spatial Variations of the ML 5.8 Gyeongju Earthquake on September 12, 2016

  • Lee, Gyeong Su (Department of Earth Science Education, Korea National University of Education) ;
  • Kyung, Jai Bok (Department of Earth Science Education, Korea National University of Education) ;
  • Lee, Sang Jun (School of Earth and Environmental Sciences, Seoul National University)
  • 투고 : 2018.08.01
  • 심사 : 2018.08.24
  • 발행 : 2018.08.31
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초록

An earthquake of $M_L$ 5.8 hit the Gyeongju area on September 12, 2016. A sequence of foreshock-mainshock-aftershock of 588 events with equal to or greater than magnitude 1.5 occurred for six months in this area. Around ninety-nine percentage (98.8%) of the total energy was released intensively within a day, and about 80% of the total events took place within a month after the Gyeongju earthquake. The epicentral distribution of aftershocks of major events ($M_L$ 5.1, 5.8, 4.5, and 3.5) were elongated in the direction of $N30^{\circ}E$. They correlate well with the focal mechanism solution. These facts support the inference that the Gyeongju earthquakes occurred on a sub-parallel subsidiary fault of the Yangsan fault zone or on the linking damage zones between Deokcheon and Yangsan fault. During the last six years before the Gyeongju earthquake, there were few events within 10-km radius from the epicenter. This seismic gap area was filled with a sequence of the Gyeongju earthquakes. The b value for aftershock of the Gyeongju earthquakes is 1.09.

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참고문헌

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