Advertisement

Geosciences Journal

, Volume 20, Issue 6, pp 747–752 | Cite as

The 12 September 2016 Gyeongju earthquakes: 1. Observation and remaining questions

  • YoungHee Kim
  • Junkee Rhie
  • Tae-Seob Kang
  • Kwang-Hee Kim
  • Minook Kim
  • Sang-Jun Lee
Letter

Abstract

Two earthquakes (M L 5.1 and 5.8) ruptured branches of the Yangsan Fault System in Gyeongju, S. Korea on September 12, 2016. After the M L 5.8 earthquake, aftershock earthquakes continued to occur, including two notable earthquakes (M L 4.3 and 4.5) on September 12 and 19, 2016. This paper details the early reports of the Yangsan Fault System in the Gyeongsang Basin from various geological and geophysical/seismological perspectives. Based on a review and an initial seismological analysis of the results of the three earthquakes (M L 5.1, 5.8, and 4.5), we present and discuss the following topics: (1) the tectonic setting and the geophysical/seismic structure of the Yangsan Fault System, (2) historical seismicity and inferred seismic hazard from historical (literature) data, and (3) source mechanisms of the three earthquakes. In the end, we highlight some of the outstanding issues with regard to earthquakes and future research topics.

Key words

Gyeongju earthquake earthquake source mechanism Yangsan Fault System Gyeongsang Basin historical seismicity 

Preview

Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.

References

  1. Chae, B.-G. and Chang, T.W., 1994, Movement History of Yangsan Fault and its Related Fractures at Chongha-Yongdok Area, Korea. Journal of the Geological Society of Korea, 30, 379–394. (in Korean with English abstract)Google Scholar
  2. Chang, K.H., Woo, B.G., Lee, J.H., Park, S.O., and Yao, A., 1990, Cretaceous and Early Cenozoic stratigraphy and history of eastern Kyongsang Basin, Korea. Journal of the Geological Society of Korea, 26, 194–205.Google Scholar
  3. Chang, C., Lee, J.B., and Kang, T.-S., 2010, Interaction between regional stress state and faults: Complementary analysis of borehole in situ stress and earthquake focal mechanism in southeastern Korea. Tectonophysics, 485, 164–177.CrossRefGoogle Scholar
  4. Choi, H.I., Oh, J.H., Shin, S.C., and Yang, M.Y., 1980, Geology and geochemistry of the Gyeongsang strata in Ulsan area. Korea Institute of Energy and Resources Bulletin, 20, 33 p.Google Scholar
  5. Chung, T.W. and Kim, W.H., 2000, Fault plane solutions for the June 26, 1997 Kyong-ju Earthquake. Journal of the Korean Geophysical Society, 3, 245–250. (in Korean with English abstract)Google Scholar
  6. Dreger, D.S. and Helmberger, D.V., 1993, Determination of source parameters at regional distances with single station or sparse network data. Journal of Geophysical Research, 98, 8107–8125.CrossRefGoogle Scholar
  7. Eberhart-Phillips, D., Thurber, C., and Fletcher, J.B., 2004, Imaging P and S attenuation in the Sacramento-San Joaquin Delta region, Northern California. Bulletin of the Seismological Society of America, 104, 2322–2336. doi: 10.1785/0120130336CrossRefGoogle Scholar
  8. Hwang, B.H., Lee, J.D., and Yang, K., 2004, Petrological study of the granitic rocks around the Yangsan Fault: Lateral displacement of the Yangsan Fault. Journal of the Geological Society of Korea, 40, 161–178. (in Korean with English abstract)Google Scholar
  9. Hwang, B.H., Lee, J.D., Yang, K., and McWilliams, M., 2007a, Cenozoic strike-slip displacement along the Yangsan Fault, southeast Korean Peninsula. International Geology Review, 49, 768–775.CrossRefGoogle Scholar
  10. Hwang, B.H., McWilliams, M., Son, M., and Yang, K., 2007b, Tectonic implication of A-type granites across the Yangsan Fault, Gigye and Gyeongju areas, southeast Korean Peninsula. International Geology Review, 49, 1094–1102.CrossRefGoogle Scholar
  11. Jeon, Y.M. and Sohn, Y.K., 2003, Sedimentary characteristics and stratigraphy implications of the Kusandong Tuff, Cretaceous Gyeongsang Basin, Korea. Geosciences Journal, 7, 53–64.CrossRefGoogle Scholar
  12. Jeong, G.Y. and Cheong, C.-S., 2005, Recurrent events on a Quaternary fault recorded in the mineralogy and micromorphology of a weathering profile, Yangsan Fault System, Korea. Quaternary Research, 64, 221–233. doi:10.1016/j.yqres.2005.05.008CrossRefGoogle Scholar
  13. Jo, N.D. and Baag, C.-E., 2003, Estimation of spectrum decay parameter k and stochastic prediction of strong ground motions in southeastern Korea. Journal of the Earthquake Engineering Society of Korea, 7, 59–70. (in Korean with English abstract)Google Scholar
  14. Kim, K.Y., Hong, J.-K., and Kim, K.-H., 1998, In-situ measurement of seismic anisotropy due to vertical fractures in the Yangsan Fault area. Journal of the Geological Society of Korea, 34, 73–80. (in Korean with English abstract)Google Scholar
  15. Kim, S.K., Jun, M.S., and Kim, J.K., 1999, Attenuation of P-waves in the Kyungsang Basin, Southeastern Korea. Journal of the Geological Society of Korea, 35, 223–228. (in Korean with English abstract)Google Scholar
  16. Kim, S.K., Park, Y.K., and Jun, M.S., 2000, Quality factor structure of the Southeastern Part of the Korean Peninsula. Journal of the Geological Society of Korea, 36, 529–544. (in Korean with English abstract)Google Scholar
  17. Kim, W., Hong, T.-K., and Kang, T.-S., 2014, Hypocentral parameter inversion for regions with poorly known velocity structures. Tectonophysics, 627, 182–192.CrossRefGoogle Scholar
  18. Kim, K.-H., Kang, T.-S., Rhie, J., Kim, Y., Park, Y., Kang, S.Y., Han, M., Kim, J., Park, J., Kim, M., Kong, C., Heo, D., Lee, H., Park, E., Park, H., Lee, S.-J., Cho, S., Woo, J.-U., Lee, S.-H., and Kim, J., 2016, The 12 September 2016 Gyeongju earthquakes: 2. Temporary seismic network for monitoring aftershocks. Geosciences Journal, 20, 753–757.Google Scholar
  19. King, G.C.P., Stein, R.S., and Lin, J., 1994, Static stress changes and the triggering of earthquakes. Bulletin of the Seismological Society of America, 84, 935–953.Google Scholar
  20. Kyung, J.B. and Lee, H.U., 1998, Intensity analysis of the 26 June 1997 Kyongju earthquake and its geological significance. The Journal of Engineering Geology, 8, 13–24. (in Korean with English abstract)Google Scholar
  21. Kyung, J.B. and Lee, K., 2006, Active fault study of the Yangsan Fault System and Ulsan Fault System, southeastern part of the Korean Peninsula. Journal of the Korean Geophysical Society, 9, 219–230.Google Scholar
  22. Lahr, J.C., 1999, HYPOELLIPSE: A Computer Program for Determining Local Earthquake Hypocentral Parameters, Magnitude, and First-Motion Pattern (Y2K Compliant Version). Open-file report 99-23, U.S. Geological Survey, Denver.Google Scholar
  23. Lee, K., Kim, K.H., and Chang, T.W., 1986, Seismicity of the Korean Peninsula (II): Seismicity of the northern part of the Yangsan Fault. Journal of the Geological Society of Korea, 22, 347–365.Google Scholar
  24. Lee, K. and Jin, Y.G., 1991, Segmentation of the Yangsan Fault System: Geophysical studies on major faults in the Kyeongsang Basin. Journal of the Geological Society of Korea, 27, 434–449.Google Scholar
  25. Lee, K. and Yang, W.-S., 2006, Historical seismicity of Korea. Bulletin of the Seismological Society of America, 96, 846–855.CrossRefGoogle Scholar
  26. Michetti, A.M., Audemard, F.A., and Marco, S., 2005, Future trends in paleoseismology: Integrated study of the seismic landscape as a vital tool in seismic hazard analyses. Tectonophysics, 408, 3–21.CrossRefGoogle Scholar
  27. Park, J.-C., Kim, W., Chung, T.W., Baag, C.-E., and Ree, J.-H., 2007, Focal mechanisms of recent earthquakes in the Southern Korean Peninsula. Geophysical Journal International, 169, 1103–1114.CrossRefGoogle Scholar
  28. Pasyanos, M.E., Dreger, D.S., and Romanowicz, B., 1996, Toward real time estimation of regional moment tensors. Bulletin of the Seismological Society of America, 86, 1255–1269.Google Scholar
  29. Rhie, J. and Kim, J., 2010, Regional moment tensor determination in the southern Korean Peninsula. Geosciences Journal, 14, 329–333. doi: 10.1007/s12303-010-0038-9CrossRefGoogle Scholar
  30. Um, S.H., Choi, H.I., Son, J.D., Oh, J.H., Kwak, Y.H., Shin, S.C., and Yun, H.S., 1983, Geological and geochemical studies on the Gyeongsang Supergroup in the Gyeongsang Basin. Korea Institute of Energy and Resources Bulletin, 36, 124. (in Korean with English abstract)Google Scholar

Copyright information

© The Association of Korean Geoscience Societies and Springer-Verlag Berlin Heidelberg 2016

Authors and Affiliations

  • YoungHee Kim
    • 1
  • Junkee Rhie
    • 1
  • Tae-Seob Kang
    • 2
  • Kwang-Hee Kim
    • 3
  • Minook Kim
    • 2
  • Sang-Jun Lee
    • 1
  1. 1.School of Earth and Environmental SciencesSeoul National UniversitySeoulRepublic of Korea
  2. 2.Division of Earth Environmental System SciencePukyong National UniversityBusanRepublic of Korea
  3. 3.Department of Geological SciencePusan National UniversityBusanRepublic of Korea

Personalised recommendations