Sedimentary and crustal thicknesses and Poisson's ratios for the NE Tibetan Plateau and its adjacent regions based on dense seismic arrays

Three‐dimensional lithospheric S wave velocity model of the NE Tibetan Plateau and western North China Craton

“…Black stars indicate earthquakes with magnitude ( M s ) ≥ 8.0. (b) Comparison of crustal thickness determined from the H ‐ κ stacking method [ H. Wang et al ., ; W. Wang et al ., ] with from the joint inversion method. Black lines indicate ±3 km deviation.…”

“…The estimated crustal thicknesses were further interpolated into meshed 0.2° × 0.2° grids of the study area (Figure a). The crustal thickness varies from ∼65 km in the NETP to ∼40 km in the western NCC (Figure ), which is consistent with previous estimates from the H ‐ κ stacking method [e.g., Li et al ., , , ; Pan and Niu , ; Tian and Zhang , ; H. Wang et al ., ; Wang et al ., ; X. Wang et al ., ; W. Wang et al ., ; Xu et al ., ; Zheng et al ., ] and active‐source seismic profiles [e.g., Jia et al ., ; Liu et al ., ; Teng et al ., ; C. Y. Wang et al ., ; S. J. Wang et al ., ]. A difference in the Moho depth is observed from the QLT to Alxa block by as much as 10 km across the HF and NQF (Figure ).…”

“…The starting model for each station was constructed using the velocity model in the top 10 km (from the results of NA), then, gradually increasing the S wave velocity to 4.57 km/s at 0.1 km/s per 2 km and connecting to the velocity of the IASPEI91 model down to 100 km depth. The V p / V s ratio in the crust was set according to the RF H ‐ κ stacking results [ W. Wang et al ., ], and the V p / V s ratio in the mantle was set to 1.80. Crustal densities were computed from the P wave velocities using the empirical relationship of Berteussen [].…”

“…Furthermore, seismic anisotropy results obtained by shear wave splitting measurements indicate that NETP exhibits a vertically coherent deformation in the lithosphere [e.g., Flesch et al ., ; Li et al ., ; Wang et al ., , ], which is inconsistent with the channel flow model. In addition, receiver function studies showed low Poisson's ratios in NETP [ Li et al ., ; Pan and Niu , ; Tian and Zhang , ; Vergne et al ., ; Wang et al ., ; X. Wang et al ., ; W. Wang et al ., ] that suggest that the crustal thickening of NETP is predominantly caused by upper crustal shortening [ Li et al ., ; Tian and Zhang , ; Vergne et al ., ] or vertically coherent shortening [ Pan and Niu , ; Wang et al ., ].…”

Constraining Sedimentary Structure Using Frequency‐Dependent P Wave Particle Motion: A Case Study of the Songliao Basin in NE China

“…We notice that the primary P arrival times have a discrepancy between horizontal and vertical components for stations located inside sedimentary basins while they should theoretically be the same since P wave is a body wave with a linear particle motion. This discrepancy leads to a P wave delay in the receiver function data generated from the two components, which has been observed by previous receiver functions studies (e.g., Chen & Niu, ; Wang et al, ). The P wave delay is likely caused by interference between the direct P and P ‐to‐ S conversion at the sediment base.…”