Abstract

In the summer of 1991 we installed 27 seismic stations about lake Baikal, Siberia, aimed at obtaining accurately timed digital seismic data to investigate the deep structure and geodynamics of the Baikal rift zone and adjacent regions. Sixty-six teleseismic events with high signal-to-noise ratio were recorded. Travel time and Q analysis of teleseisms characterize an upwarp of the lithosphere-asthenosphere boundary under Baikal. Theoretical arrival times were calculated by using the International Association of Seismology and Physics of the Earth's interior 1991 Earth model, and travel time residuals were found by subtracting computed arrival times from observed ones. A three-dimensional downward projection inversion method is used to invert the P wave velocity structure with constraints from deep seismic sounding data. Our results suggest that (1) the lithosphere-asthenosphere transition upwarps beneath the rift zone, (2) the upwarp has an asymmetric shape, (3) the velocity contrast is -4.9% in the asthenosphere, (4) the density contrast is -0.6%, and (5) the P wave attenuation contrast t* is 0.1 s.

Department(s)

Geosciences and Geological and Petroleum Engineering

Keywords and Phrases

athenosphere; lithosphere/asthenosphere transition; rift; seismic survey; topography; Russian Federation; Baikal Rift Zone

Geographic Coverage

Siberia

International Standard Serial Number (ISSN)

0148-0227

Document Type

Article - Journal

Document Version

Final Version

File Type

text

Language(s)

English

Rights

© 1994 American Geophysical Union (AGU), All rights reserved.

Included in

Geology Commons

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Article Location

 
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