Approach to the Earthquake Prediction by Analyzing Foreshocks of Large Korean Historical Earthquakes

역사지진에서 강진의 전진에 대한 특성 분석을 통한 지진 예지에 대한 고찰

  • E, Sang-Hion (Seismology & Environmental Geophysics Lab, School of Earth & Environmental Sciences, Seoul National University) ;
  • Lee, Kie-Hwa (School of Earth & Environmental Sciences, Seoul National University)
  • 이상현 (서울대학교 지구환경과학부 지진환경지구물리연구실) ;
  • 이기화 (서울대학교 지구환경과학부)
  • Published : 2005.09.01

Abstract

Seismicity changes associated with foreshocks of large Korean historical earthquakes of MMI > VIII are investigated for earthquake prediction study. A number of tests showed that b-values of foreshocks associated with these large earthquakes are most stable for precursor period of 13 years before the earthquake and rectangular source area of 1.1o by 1.1o around the epicenter. The b-values of foreshocks for 11 large events of MMI > VIII for the above foreshock area and precursor period turns out to be smaller than the value of 0.36 for the whole historical earthquakes with average 0.27. Epicenters of these foreshocks of small b-values are distributed close to the location of the main large earthquake. These observations indicate a possibility of predicting large earthquakes by closely monitoring the change of b-value for an extended period over decades in the Korean peninsula.

본 연구에서는 지진 예지 연구를 위하여 한반도에서 발생한 MMI 진도가 VIII 보다 큰 역사 지진들의 전진들에 대하여 지진활동도의 변화를 분석하였다. 한반도에서의 강진에 대하여 13년의 전진기간과 진앙을 중심으로 위도 1.1o, 경도 1.1o 크기의 사각형 모양의 전진범위를 가정했을 경우 가장 안정적인 전진들의 b값을 도출할 수 있었다. 이 전진기간과 전진범위에 의해 결정된 11개의 MMI 진도 VIII 이상의 강진의 전체 전진들에 대한 b값은 전체 역사지진의 b값인 0.36에 비해 확연히 작은 0.27로 결정되었다. 또한 강진 발생을 앞두고 작은 b값을 가지는 지진들이 강진의 진앙 근처에서 집중적으로 발생하였다. 본 연구를 통해 십 수 년 동안의 b값의 변화를 자세히 관찰함으로써 강진의 예지가 가능하다는 것이 확인되었다.

Keywords

References

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