caa a22 4500 445299738 CHVBK 20180317142553.0 cr unu---uuuuu 170323e20100901xx s 000 0 eng 10.1007/s11430-010-4037-5 doi (NATIONALLICENCE)springer-10.1007/s11430-010-4037-5 P-wave tomographic images beneath southeastern Tibet: Investigating the mechanism of the 2008 Wenchuan earthquake [Elektronische Daten] [Wei Wei, RuoMei Sun, YaoLin Shi] We used 71670 P-wave arrival times from 3594 earthquakes recorded by the Sichuan and Yunnan seismic networks to determine the three-dimensional P-wave velocity structure in the crust and uppermost mantle beneath the southeastern Tibetan Plateau. Our results show that prominent low P-wave velocity (low-Vp) anomalies exist in the mid- to lower crust of the Songpan-Ganze and Sichuan-Yunnan blocks. In contrast, a high P-wave velocity (high-Vp) anomaly is resolved in the middle and lower crust beneath the Sichuan Basin. Our tomographic results provide seismic evidence for a dynamic model of lower crustal flow. Ongoing lower crustal flow beneath the central and eastern Tibetan Plateau abuts against the mechanically strong Sichuan Basin resulting in accumulated strain in the Longmen Shan region. When a critical accumulation of strain energy was reached, its sudden release led to the occurrence of 2008 Wenchuan earthquake. Pronounced low-Vp anomalies are observed in the uppermost mantle in the region south of ∼26°N. Combining these results with shear-wave splitting investigations, we suggest that the flow of asthenospheric material has impacted the velocity structure of the uppermost mantle and caused the thinning of the southwestern Yangtze Craton. Science China Press and Springer-Verlag Berlin Heidelberg, 2010 seismic tomography nationallicence Sichuan-Yunnan Block nationallicence Wenchuan earthquake nationallicence Longmenshan fault nationallicence Yangtze Craton nationallicence Wei Wei Laboratory of Computational Geodynamics, Graduate University of Chinese Academy of Sciences, 100049, Beijing, China aut Sun RuoMei Institute of Geology and Geophysics, Chinese Academy of Sciences, 100029, Beijing, China aut Shi YaoLin Laboratory of Computational Geodynamics, Graduate University of Chinese Academy of Sciences, 100049, Beijing, China aut Science China Earth Sciences SP Science China Press 53/9(2010-09-01), 1252-1259 1674-7313 53:9<1252 2010 53 11430 https://doi.org/10.1007/s11430-010-4037-5 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s11430-010-4037-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Wei Wei Laboratory of Computational Geodynamics, Graduate University of Chinese Academy of Sciences, 100049, Beijing, China aut NATIONALLICENCE 700 1- Sun RuoMei Institute of Geology and Geophysics, Chinese Academy of Sciences, 100029, Beijing, China aut NATIONALLICENCE 700 1- Shi YaoLin Laboratory of Computational Geodynamics, Graduate University of Chinese Academy of Sciences, 100049, Beijing, China aut NATIONALLICENCE 773 0- Science China Earth Sciences SP Science China Press 53/9(2010-09-01), 1252-1259 1674-7313 53:9<1252 2010 53 11430 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer