Crustal Structure of the Continental Margin of Korea in the East Sea: Results From Deep Seismic Sounding

한반도의 동해 대륙주변부의 지각구조 : 심부 탄성파탐사결과

  • 김한준 (한국해양연구원 지구환경연구본부) ;
  • 조현무 (서울대학교 지구환경과학부) ;
  • 주형태 (한국해양연구원 지구환경연구본부) ;
  • 홍종국 (한국해양연구원 지구환경연구본부) ;
  • 유해수 (한국해양연구원 지구환경연구본부) ;
  • 박창업 (서울대학교 지구환경과학부)
  • Published : 2003.02.01


Despite the various opening models of the southwestern part of the East Sea (Japan Sea) between the Korean Peninsula and the Japan Arc, the continental margin of the Korean Peninsula remains unknown in crustal structure. As a result, continental rifting and subsequent seafloor spreading processes to explain the opening of the East Sea have not been adequately addressed. We investigated crustal and sedimentary velocity structures across the Korean margin into the adjacent Ulleung Basin from multichannel seismic reflection and ocean bottom seismometer data. The Ulleung Basin shows crustal velocity structure typical of oceanic although its crustal thickness of about 10 km is greater than normal. The continental margin documents rapid transition from continental to oceanic crust, exhibiting a remarkable decrease in crustal thickness accompanied by shallowing of Moho over a distance of about 50 km. The crustal model of the margin is characterized by a high-velocity (up to 7.4 km/s) lower crustal (HVLC) layer that is thicker than 10 km under the slope base and pinches out seawards. The HVLC layer is interpreted as magmatic underplating emplaced during continental rifting In response to high upper mantle temperature. The acoustic basement of the slope base shows an igneous stratigraphy developed by massive volcanic eruption. These features suggest that the evolution of the Korean margin can be explained by the processes occurring at volcanic rifted margins. Global earthquake tomography supports our interpretation by defining the abnormally hot upper mantle across the Korean margin and in the Ulleung Basin.


  1. 최호선, 2000, 한국 남동지역의 지각속도구조 추정, 서울대학교 석사학위논문
  2. Anderson, D.L., Tanimoto, T., and Zhang, Y.-S., 1992, Plate tectonics and hotspots: the third dimension: Science, 256, 1645-1650
  3. Barry, T. L. and Kent, ., 1998, Cenozoic magmatism in Mongolia and the origin of central and east Asian basalts, in Flower, M.F.J., Chung, S.-L., Lo, C.-H., Lee, T.-Y, Eds., Mantle dynamics and plate interactions in east Asia: American Geophysical Union, 347-364
  4. Bijwaard, H., Spakman, K., and Engdahl, E. R., 1998, Closing the gap between regional and global travel time tomography: J. Geophys. Res., 103, 30055-30078
  5. Cerveny, V., Molotkov, I. A., and Psentik, I., 1977, Ray method in seismology: University of Carlova, Prague
  6. Christensen, N. I. and Mooney, W. D., 1995, Seismic structure and composition of the continental crust: A global view: J. Geophys. Res., 100, 9761-9788
  7. Curtis, A., Trampert, J., and Snieder, R., 1998, Eurasian fundamental mode surface wave phase velocities and their relationship with tectinic structures: J. Geophys. Res., 103, 26919-226947
  8. Eldholm, O. and Grue, K., 1994, North Atlantic volcanic margins: Dimensions and production rates: J. Geophys. Res., 99, 2955-2968
  9. Goldschmidt-Rokita, A., Hansch, K. J. F., Hirschleber, H. B., Iwasaki, T., Kanazawa, T., Shimamura, H., and Sellevoll, M. A., 1994, The ocean/continent transition along a profile through the Lofoten Basin, northern Norway: Marine Geophys. Res., 16, 201-224
  10. Hashizume, M. and Matsui, Y., 1979, Crustal structure of southwestern Honshu, Japan, derived from explosion seismic waves: Gophys. J. Roy. Astr. Soc., 58, 181-199
  11. Ingle, Jr., J. C., 1992. Subsidence of the Japan Sea: stratigraphic evidence from ODP sites and onshore sections: Ocean Dri. Prog., 127/128, 1197-1218
  12. Jolivet, L., Tamaki, K., and Fournier, M., 1994, Japan Sea, opening history and mechanism: A synthesis: J. Geophys. Res., 99, 22237-22259
  13. Jou, H. T., Kim, H. J., Suh, J. H., and Youn, O. K., 1996. A new slant-stack technique based on hyperbolic statistics: J. Seismic Exploration, 5, 203-212
  14. Keen, C. E. and Potter, D. P., 1995, The transition from a volcanic to a nonvolcanic rifted margin off eastern Canada: Tectonics, 14, 359-371
  15. Kelemen, P. B. and Holbrook, W. S., 1995, Origin of thick, high-velocity igneous crust along the U.S. East Coast Margin: J. Geophys. Res., 100, 10077-10094
  16. Kido, Y., Suyehiro, K., and Kinoshita, H., 2001, Rifting to spreading process along the northern continental margin of the South China Sea: Marine Geophys. Res., 22, 1-15
  17. Kim, H. J. and Marillier, F., 1996, Analytic minimum information deconvolution and its application to ocean bottom seismometer data: Geophys. Res. Lett., 23, 1973-1976
  18. Kim, H. J., Han, S. J., Lee, G. H., and Huh, S., 1998, Seismic study of the Ulleung Basin crust and its implications for the opening of the East Sea (Japan Sea): Marine Geophys. Res., 20, 219-237
  19. Lee, G. H., Kim, H. J., Suh, M. C., and Hong, J. K., 1999, Crustal structure, volcanism, and opening of the Ulleung Basin, East Sea (Sea of Japan): Tectonophysics, 308, 503-525
  20. Liu, G. D., 1987. The Cenozoic rift system of the North China plain and the deep internal processes: Tectonophysics, 133, 277-285
  21. Mutter, J. C., Buck, W. R., and Zehnder, C. M., 1988, Convective partial melting, I. A model for the formation of thick basaltic sequences during the initiation of spreading: J. Geophys. Res., 93, 1031-1048
  22. Otofuji, Y., 1996, Large tectonic movement of the Japan Arc in late Cenozoic times inferred from paleomagnetism: review and synthesis: The Island Arc, 5, 229-249
  23. Purdy, G. M., 1986, Seismic structure of the oceanic crust, in Vogt, P.R., and Tucholke, B.E., Eds., The Geology of North America M, The Western North Atlantic Region: Geol. Soc. Am., 313-330
  24. Reid, I. D., 1994, Crustal structure of a nonvolcanic rifted margin east of Newfoundland: J. Geophys. Res., 99, 15161-15180
  25. Rohr, K. M., 1994, Increase of seismic velocities in upper oceanic crust and hydrothermal circulation in the Juan de Fuca plate: Geophys. Res. Lett., 21, 2163-2166
  26. Skogseid, J. and Eldholm, O., 1987, Early Cenozoic crust at the Norwegian continental margin and the conjugate Jan Mayen Ridge: J. Geophys. Res., 92, 11471-11491
  27. Smith, A. D., 1998, The gedynamic sigmficance of the DUPAL anomaly in Asia, in Flower, M.F.J., Chung, S.-L., Lo, C.-H., Lee, T.-Y., Eds., Mantle dynamics and plate interactions in east Asia: American Geophysical Union, pp. 89-105
  28. Tamaki, K., Suyehiro, K., Allan, J., Ingle Jr. J. C., and Pisciotto, A., 1992, Tectonic synthesis and implications of Japan Sea ODP Drilling: Ocean Dri. Prog., 127/128, 1333-1348
  29. White, R. and McKenzie, D., 1989, Magmatism at rift zones: the generation of volcanic continental margins and flood basalts: J. Geophys. Res., 94, 7685-7729
  30. Whitmarsh, R. B., Pinheiro, L. M., Miles, P. R., Recq, M., and Sibuet, J.-C., 1993, Thin crust at the western Iberia oceancontinent transition and ophiliolites: Tectonics, 12, 1230-1239
  31. Windley, B. F. and Allen, M. B., 1993, Mongolian Plateau: evidence for a Late Cenozoic mantle plume under Central Asia: Geology, 21, 295-298
  32. Yoon, S. H. and Chough, S. K., 1995, Regional strike slip in the eastern continental margin of Korea and its tectonic implications for the evolution of Ulleung Basin, East Sea (Sea of Japan): Geol. Soc. Am. Bull., 107, 83-97
  33. Zelt, C. A. and Barton, P. J., 1998, 3-D seismic refraction tomography: A comparison of two methods applied to data from the Faeroe Basin: J. Geophys. Res., 103, 7187-7210