CRUST AND MANTLE OF THE BAIKAL RIFT ZONE FROM P- AND S-WAVE RECEIVER FUNCTIONS
We have obtained P-wave and S-wave receiver functions for 10 broadband seismograph stations in the Baikal rift zone (BRZ) and inverted them for seismic velocity models of the crust and upper mantle. The thinnest crust (30–35 km) is found in the Baikal basin, the thickest in the East Sayan uplift (45...
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| Format: | Article |
| Language: | English |
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Russian Academy of Sciences, Siberian Branch, Institute of the Earth's crust
2017-12-01
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| Series: | Геодинамика и тектонофизика |
| Subjects: | |
| Online Access: | https://www.gt-crust.ru/jour/article/view/466 |
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| author | L. P. Vinnik S. I. Oreshin L. R. Tsydypova V. V. Mordvinova M. M. Kobelev M. A. Khritova Ts. A. Tubanov |
| author_facet | L. P. Vinnik S. I. Oreshin L. R. Tsydypova V. V. Mordvinova M. M. Kobelev M. A. Khritova Ts. A. Tubanov |
| author_sort | L. P. Vinnik |
| collection | DOAJ |
| description | We have obtained P-wave and S-wave receiver functions for 10 broadband seismograph stations in the Baikal rift zone (BRZ) and inverted them for seismic velocity models of the crust and upper mantle. The thinnest crust (30–35 km) is found in the Baikal basin, the thickest in the East Sayan uplift (45–50 km). Intermediate values (40 km) are found in the BRZ at distances around 100 km from Lake Baikal. A high (at least 1.8) Vp/Vs ratio is observed in the middle and lower crust. It exceeds 2.0 at some stations. In our opinion, the highest Vp/Vs ratios are due to fluid-filled porosity with a high pore pressure. The seismic lithosphere – asthenosphere boundary (LAB) is manifested by a shear velocity drop from 4.5 km/s to 4.0–4.2 km/s. Beneath the Baikal basin, the LAB is located at a depth not more than 50 km, and the S velocity drop is maximal (10 %). A similar structure is found outside the basin, underneath a segment of the East Sayan uplift. At other locations in the BRZ, a typical depth of the LAB varies from 80 to 90 km. Having considered changes in the depth of the 410 km seismic discontinuity, we cannot find any evidence of an elevated temperature of a hypothetical thermal plume beneath the BRZ. |
| first_indexed | 2024-04-09T20:29:23Z |
| format | Article |
| id | doaj.art-ddae8475d9fd4784bd2216fa487b0555 |
| institution | Directory Open Access Journal |
| issn | 2078-502X |
| language | English |
| last_indexed | 2025-03-14T08:31:21Z |
| publishDate | 2017-12-01 |
| publisher | Russian Academy of Sciences, Siberian Branch, Institute of the Earth's crust |
| record_format | Article |
| series | Геодинамика и тектонофизика |
| spelling | doaj.art-ddae8475d9fd4784bd2216fa487b05552025-03-02T13:02:47ZengRussian Academy of Sciences, Siberian Branch, Institute of the Earth's crustГеодинамика и тектонофизика2078-502X2017-12-018469570910.5800/GT-2017-8-4-0313309CRUST AND MANTLE OF THE BAIKAL RIFT ZONE FROM P- AND S-WAVE RECEIVER FUNCTIONSL. P. Vinnik0S. I. Oreshin1L. R. Tsydypova2V. V. Mordvinova3M. M. Kobelev4M. A. Khritova5Ts. A. Tubanov6O.Yu. Schmidt Institute of Physics of the Earth of RASO.Yu. Schmidt Institute of Physics of the Earth of RASGeological Institute, Siberian Branch of RASInstitute of the Earth’s Crust, Siberian Branch of RASBaikal Branch of Federal Research Center ‘Geophysical Survey of RAS’Baikal Branch of Federal Research Center ‘Geophysical Survey of RAS’Geological Institute, Siberian Branch of RASWe have obtained P-wave and S-wave receiver functions for 10 broadband seismograph stations in the Baikal rift zone (BRZ) and inverted them for seismic velocity models of the crust and upper mantle. The thinnest crust (30–35 km) is found in the Baikal basin, the thickest in the East Sayan uplift (45–50 km). Intermediate values (40 km) are found in the BRZ at distances around 100 km from Lake Baikal. A high (at least 1.8) Vp/Vs ratio is observed in the middle and lower crust. It exceeds 2.0 at some stations. In our opinion, the highest Vp/Vs ratios are due to fluid-filled porosity with a high pore pressure. The seismic lithosphere – asthenosphere boundary (LAB) is manifested by a shear velocity drop from 4.5 km/s to 4.0–4.2 km/s. Beneath the Baikal basin, the LAB is located at a depth not more than 50 km, and the S velocity drop is maximal (10 %). A similar structure is found outside the basin, underneath a segment of the East Sayan uplift. At other locations in the BRZ, a typical depth of the LAB varies from 80 to 90 km. Having considered changes in the depth of the 410 km seismic discontinuity, we cannot find any evidence of an elevated temperature of a hypothetical thermal plume beneath the BRZ.https://www.gt-crust.ru/jour/article/view/466vp/vs ratiofluid-filled porositymantlemantle plumelithosphere – asthenosphere boundary |
| spellingShingle | L. P. Vinnik S. I. Oreshin L. R. Tsydypova V. V. Mordvinova M. M. Kobelev M. A. Khritova Ts. A. Tubanov CRUST AND MANTLE OF THE BAIKAL RIFT ZONE FROM P- AND S-WAVE RECEIVER FUNCTIONS Геодинамика и тектонофизика vp/vs ratio fluid-filled porosity mantle mantle plume lithosphere – asthenosphere boundary |
| title | CRUST AND MANTLE OF THE BAIKAL RIFT ZONE FROM P- AND S-WAVE RECEIVER FUNCTIONS |
| title_full | CRUST AND MANTLE OF THE BAIKAL RIFT ZONE FROM P- AND S-WAVE RECEIVER FUNCTIONS |
| title_fullStr | CRUST AND MANTLE OF THE BAIKAL RIFT ZONE FROM P- AND S-WAVE RECEIVER FUNCTIONS |
| title_full_unstemmed | CRUST AND MANTLE OF THE BAIKAL RIFT ZONE FROM P- AND S-WAVE RECEIVER FUNCTIONS |
| title_short | CRUST AND MANTLE OF THE BAIKAL RIFT ZONE FROM P- AND S-WAVE RECEIVER FUNCTIONS |
| title_sort | crust and mantle of the baikal rift zone from p and s wave receiver functions |
| topic | vp/vs ratio fluid-filled porosity mantle mantle plume lithosphere – asthenosphere boundary |
| url | https://www.gt-crust.ru/jour/article/view/466 |
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