지구물리와물리탐사 (Geophysics and Geophysical Exploration)

  • 제20권1호
  • /
  • Pages.18-24
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  • 2017
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  • 1229-1064(pISSN)
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  • 2384-051X(eISSN)
한국지구물리·물리탐사학회 (Korean Society of Earth and Exploration Geophysicists)
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동아시아 S파 상대 주시 토모그래피

S-wave Relative Travel Time Tomography for East Asia

  • 조성흠 (강원대학교 지질.지구물리학부) ;
  • 장성준 (강원대학교 지질.지구물리학부)
  • Cho, Seongheum (Division of Geology and Geophysics, Kangwon National University) ;
  • Chang, Sung-Joon (Division of Geology and Geophysics, Kangwon National University)
  • 투고 : 2016.11.29
  • 심사 : 2017.01.09
  • 발행 : 2017.02.28
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초록

동아시아 지역의 S파 맨틀속도구조를 파악하기 위해, 한반도와 일본 지역에 설치된 129개의 광대역 속도 관측소상에 기록된 원거리 지진 자료를 이용하여 S파 상대 주시 토모그래피를 수행하였다. 보다 정확한 S파 상대 주시의 계산을 위해 다중 채널 상호 상관법을 적용하였으며 파선이론을 기초로 역산을 수행하였다. 역산 결과 주요 판의 경계를 따라 섭입하는 태평양판과 필리핀해판이 고속도 이상으로 나타났으며, 맨틀 전이대를 따라 수평으로 존재하는 태평양판이 확인되었다. 또한 한반도 동부의 하부에서 약 300 km 깊이까지 저속도 이상이 발견되었으며, 이 저속도 이상체는 울릉분지와 울릉도 형성에 연관이 있을 것으로 판단된다. 제주도 하부 200 ~ 700 km 사이에 나타나는 저속도 이상은 제주도의 형성과 관련이 있을 것으로 생각되며, 이와 같은 저속도 이상체들은 한반도 주요 화산 활동의 근원이 깊은 맨틀에서부터 시작되었음을 알 수 있는 중요한 근거로 생각된다.

We performed seismic imaging based on relative S-wave travel times to examine S-wave velocity of upper mantle structure beneath East Asia. We used teleseismic events recorded at 129 broadband stations of the Korea Institute of Geoscience and Mineral Resources (KIGAM), Korea Meteorological Administration (KMA), and National Research Institute for Earth Science and Disaster Prevention (NIED). Relative travel time residuals were obtained by a multi-channel cross-correlation method designed to automatically determine accurate relative phase arrival times. The resulting images show high-velocity anomalies along plate boundaries around the Japanese islands region. These anomalies may indicate subducting Pacific and Philippine Sea plates. On the other hand, a low-velocity anomaly is revealed beneath east of the Korean peninsula down to around 300 km depth, which is thought to be related to the formation of the Ulleung basin and the Ulleung island. Low-velocity anomalies revealed beneath the Jeju island may imply that the formation and volcanism of the Jeju island have been caused by magmatic sources from the deep mantle.

키워드

참고문헌

  1. Abdelwahed, M., and Zhao, D., 2007, Deep structure of the Japan subduction zone, Physics of the Earth and Planetary Interiors, 162, 32-52. https://doi.org/10.1016/j.pepi.2007.03.001
  2. Asamori, K., and Zhao, D., 2015, Teleseismic shear wave tomo-graphy of the Japan subduction zone, Geophysical Journal International, 203, 1752-1772.
  3. Bird, P., 2003, An updated digital model of plate boundaries, Geochemistry, Geophysics, Geosystems, 4, 1027, doi:10.1029/2001GC000252.
  4. Brenna, M., Cronin, S., Kereszturi, G., Sohn, Y., Smith, I. M.,and Wijbrans, J., 2015, Intraplate volcanism influenced by distal subduction tectonics at Jeju Island, Republic of Korea, Bulletin of Volcanology, 77, 1-16. https://doi.org/10.1007/s00445-014-0893-8
  5. Chang, S.-J., and Baag, C.-E., 2005, Crustal structure in southern Korea from joint analysis of teleseismic receiver functions and surface wave dispersion, Bulletin of the Seismological Society of America, 95, 1516-1534. https://doi.org/10.1785/0120040080
  6. Chang, S.-J., and Baag, C.-E., 2007, Moho depth and crustal Vp/Vs variation in southern Korea from teleseismic receiver functions: Implication for tectonic affinity between the Korean Peninsula and China, Bulletin of Seismological Society of America, 97, 1621-1631. https://doi.org/10.1785/0120050264
  7. Fukao, Y., Widiyantoro, S., and Obayashi, M., 2001, Stagnant slabs in the upper and lower mantle transition region, Reviews of Geophysics, 39, 291-323. https://doi.org/10.1029/1999RG000068
  8. Kennett, B. L. N., and Engdahl, E. R., 1991, Travel times for global earthquake location and phase association, Geophysical Journal International, 105, 429-465. https://doi.org/10.1111/j.1365-246X.1991.tb06724.x
  9. Kim, S., Tkalcic, H., Rhie, J., and Y. Chen, 2016, Intraplate volcanism controlled by back-arc and continental structures in NE Asia inferred from transdimensional Bayesian ambient noise tomography, Geophysical Research Letters, 43, 8390-8398, doi:10.1002/2016GL069483.
  10. Li, C., and van der Hilst, R. D., 2010, Structure of the upper mantle and transition zone beneath Southeast Asia from traveltime tomography, Journal of Geophysical Research,115, B07308, doi:10.1029/2009JB006882.
  11. Liu, X., and Zhao, D., 2016, P and S wave tomography of Japan subduction zone from joint inversions of local and teleseismic travel times and surface-wave data, Physics of the Earth and Planetary Interiors, 252, 1-22. https://doi.org/10.1016/j.pepi.2016.01.002
  12. Lou, X., van der Lee, S., and Lloyd, S., 2013, AIMBAT: A Python/Matplotlib tool for measuring teleseismic arrival times, Seismological Research Letters, 84, 85-93. https://doi.org/10.1785/0220120033
  13. Simute, S., Steptoe, H., Cobden, L., Gokhberg, A., and Fichtner, A., 2016, Full-waveform inversion of the Japanese Islands region, Journal of Geophysical Research: Solid Earth, 121,doi:10.1002/2016JB012802.
  14. VanDecar, J. C., and Crosson, R. S., 1990, Determination of teleseismic relative phase arrival times using multi-channel cross-correlation and least-squares, Bulletin of the Seismological Society of America, 80, 150-169.
  15. VanDecar, J. C., 1991, Upper-mantle structure of the Cascadia subduction zone from non-linear teleseismic travel-time inversion, Ph.D. thesis, University of Washington, Seattle.
  16. Wei, W., Zhao, D., Xu, J., Wei, F., and Liu, G., 2015, P and S wave tomography and anisotropy in Northwest Pacific and East Asia: Constraints on stagnant slab and intraplate volcanism, Journal of Geophysical Research: Solid Earth, 120, 1642-1666, doi:10.1002/2014JB011254.
  17. Witek, M., van der Lee, S., and Kang, T.-S., 2014, Rayleigh wave group velocity distributions for East Asia using ambient seismic noise, Geophysical Research Letters, 41, 8045-8052,doi:10.1002/2014GL062016.
  18. Zhao, D., and Ohtani, E., 2009, Deep slab subduction and dehydration and their geodynamic consequences: evidence from seismology and mineral physics, Gondwana Research,16, 401-413. https://doi.org/10.1016/j.gr.2009.01.005