Direct Surface Wave Radial Anisotropy Tomography in the Crust of the Eastern Himalayan Syntaxis. Issue 5 (1st May 2020)

• Record Type: Journal Article
• Authors: Hu, Shaoqian; Yao, Huajian; Huang, Hui
• Is Part Of: Journal of geophysical research. Volume 125:Issue 5(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2020-05-01
• Subjects: radial anisotropy -- ambient noise tomography -- eastern Himalayan syntaxis -- crustal structure; Geomagnetism -- Periodicals; Geochemistry -- Periodicals; Geophysics -- Periodicals; Earth sciences -- Periodicals; 551.1
• DOI: 10.1029/2019JB018257
• Languages: English
• ISSNs: 2169-9313

Abstract

Abstract: A novel method is implemented to invert Rayleigh and Love wave dispersion curves of all paths jointly for 3‐D shear wave velocity and radial anisotropy simultaneously without intermediate steps. We use the method to derive high‐precision crustal shear wave velocity and radial anisotropy models around the eastern Himalayan syntaxis using ambient noise dispersion data (5–40 s). Results show that the crust can be divided into several subregions with different rigidity and preferred mineral alignment orientation depth‐dependently. In the middle crust, combined with other geophysical observations, 3‐D geometry of two continuous branches of eastward channelized weak zones is outlined in detail. Both branches of the weak zone are blocked by the high velocity zone with radial anisotropy of V s h > V s v at around 96–97°E. In the upper crust, the radial anisotropy model depicts a complex pattern, which is associated with the ongoing surface uplifting and shear strain rate distribution. Key Points: A novel method of 3‐D direct surface wave radial anisotropy tomography is implemented High‐resolution crustal V S and radial anisotropy model of the eastern Himalayan syntaxis is derived using ambient noise data The models reveal depth‐dependent rigidity and outline 3‐D geometry of the mid‐crustal channelized weak zone