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Velocity structure of the Northern Baikal Rift, Siberia, from local and regional earthquake travel times
Author(s) -
Petit Carole,
Déverchère Jacques
Publication year - 1995
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/95gl01605
Subject(s) - rift , geology , seismology , lithosphere , hypocenter , crust , inversion (geology) , discontinuity (linguistics) , geophysics , induced seismicity , tectonics , mathematical analysis , mathematics
The velocity structure of the upper lithosphere in the Northern Baikal rift (NBR), Siberia, is analyzed in order to bring some constraints on the early stages of continental rifting. A simultaneous hypocenter‐velocity inversion is performed using a set of local and regional seismological data recorded in the NBR. First‐arrival times of 3,492 direct and refracted P and S waves allow to investigate the crustal velocity structure and the Moho geometry. Results of inversion reveal an unbalanced crust made of two adjacent parts of different thickness, delimited by a rather sharp discontinuity following approximately the northern edge of the rift zone. This structure is interpreted as the result of ante‐rift deformation phases, creating a weakened zone where rifting deformation may easily occur. Oblique rifting is invoked to explain the formation of sedimentary basins without significant crustal thinning at depth.