대규모 발파를 통한 한반도 지각의 2차원적 횡파 속도구조 연구

Two-dimensional shear-wave velocity structures of the Korea peninsula from large explosions

  • 김기영 (강원대학교 지구물리학과) ;
  • 홍명호 (강원대학교 지구물리학과) ;
  • 이정모 (경북대학교 지질학과) ;
  • 문우일 (서울대학교 지구환경과학부) ;
  • 박창업 (서울대학교 지구환경과학부) ;
  • 정희옥 (군산대학교 해양시스템공학과)
  • Kim, Ki-Young (Dept. of Geophysics, Kangwon National University) ;
  • Hong, Myung-Ho (Dept. of Geophysics, Kangwon National University) ;
  • Lee, Jung-Mo (Dept. of Geology, Kyungpook National University) ;
  • Moon, Woo-Il (School of Earth & Environmental sciences, Seoul National University) ;
  • Baag, Chang-Eob (School of Earth & Environmental sciences, Seoul National University) ;
  • Jung, Hee-Ok (Dept. of Ocean System Engineering, Kunsan National University)
  • 발행 : 2007.06.07

초록

To investigate the shear-wave velocity structures of the Korean peninsula, exploded seismic signals were recorded for 120 s along a 294-km WNW-ESE line and 150 s along a 335-km NNW-SSE line in 2002 and 2004, respectively. First arrival times of shear wave were inverted to derive the velocity tomograms. Initial shear-wave 1-D models were built using the initial P-wave velocity models used by Kim et al. and $V_p/V_s$ ratios of the IASP91 model. The raypaths indicate existence of mid-crust interfaces at the depth of 2-3 km and 16 km. The deepest significant interface corresponding to the Moho discontinuity varies in depth from 32 km to 36 km. The refraction velocity along the interface varies from 4.4 km/s to 4.6 km/s. The velocity tomograms also indicate existence of a low-velocity zone at the depth of 7.8 km under the Okchon fold belt.

키워드