Browse > Article
http://dx.doi.org/10.5000/EESK.2003.7.5.019

A source and phase identification study of the 10 December 2002 Cheolwon, Korea, earthquake of ML 3.6  

김우한 (경상대학교 지구환경과학과)
박종찬 (경상대학교 지구환경과학과)
함인경 (경상대학교 지구환경과학과)
김성균 (전남대학교 지구환경과학과)
박창업 (서울대학교 지구환경과학부)
Publication Information
Journal of the Earthquake Engineering Society of Korea / v.7, no.5, 2003 , pp. 19-24 More about this Journal
Abstract
We analysed seismic phases recorded by the 10 December 2002 Cheolwon, Korea, earthquake of $M_{L}$ 3.6 and obtained source parameters such as hypocenter, origin time, earthquake magnitude. Velocity and acceleration records used in this study are from the KMA and KIGAM seismic networks. Due to the location of the epicenter in the north of the DMZ(Demilitarized Zone), direct Pg phases were recorded only at five stations in the area south of DMZ. Identification of refracted Pn phase as the first arrival is difficult in most stations. Therefore, the hypocenter determined by existing routine methods could be affected by a large error. In order to avoid the possibility of the problem, we employed a method of seismic phase analysis developed by Kim et al.. The direct, refracted, and reflected P and S phases were successfully identified using the method together with the travel time curve data. In order to improve the accuracy in determination of the hypocenter and origin time, we included PmP and SmS phases in the analysis in addition to the phases such as Pg, Pn, Sg and Sn. The epicenter, depth, and origin time of the Cheolwon earthquake determined based on data of 11 stations within 200km from the epicenter are $38.81^{\circ}$N, $127.22^{\circ}$E, 12.0km, and 7:42:51.4(local time), respectively. The average value of the local magnitude based on the Richter's definition from all the stations is 3.6 in $M_{L}$. This magnitude is smaller by 0.2 and 0.5 compared with magnitudes determined by KMA and KIGAM, respectively.
Keywords
the 10 December 2002 Cheolwon; Korea; earthquake; phase analysis; hypocenter; origin time; local magnitude;
Citations & Related Records
연도 인용수 순위
  • Reference
1 Kim, W. and Baag, C-E., “Rappid and accurate two point ray tracing based on quadratic equation of take-off angle in a layered media with constant or linearly varying velocity functions,” Bull. Seismo. Soc. Am., 92, 2002, pp. 2251-2263.   DOI   ScienceOn
2 Kim, W., “P-wave velocity structure in the vicinity of the Yangsan Fault region,” Geosciences J., 3, 1999, pp. 17-22.   과학기술학회마을   DOI
3 박종찬, 김우한, 파형분석과 두점을 잇는 파선추적을 이용한 지진요소 결정, 한국지진공학회논문집, 5, 2001, pp. 57-61.   과학기술학회마을
4 김성균, 박민아, “한반도의 국지 지진규모, 지질학회지”, Vol. 38, No. 2, 2002, pp. 217-235.   과학기술학회마을
5 Lee, W. H. K. and Lahr, J. C., HYPO71PC(revised) : “A computer program for determining hypocenter, magnitude, and first motion pattern of local earthquakes,” Geological Survey Open-File Rep.(U.S.), 9, 1-116, 1975, pp. 75-311.
6 Kim, W., Park, J., and Baag, C.-E., “Phase analysis using directionality and rectilinearity functions in three component seismograms,” Submitted to Bull. Seismo. Soc. Am, 2003.
7 Richter, C. F., Elementary Seismology, W. H. Freeman and Co., San Francisco, 1958, 758 pp.