| Title | Characteristics and Removal of Continuous Topographic Scattering in Dense Array Receiver Function Imaging |
| Authors | Zhang, Siyuan Ge, Zengxi Guo, Zhen |
| Affiliation | Peking Univ, Sch Earth & Space Sci, Beijing, Peoples R China Hebei Hongshan Natl Observ Thick Sediments & Seis, Beijing, Peoples R China Southern Univ Sci & Technol, Dept Ocean Sci & Engn, Shenzhen, Peoples R China Southern Marine Sci & Engn Guangdong Lab Guangzho, Shenzhen, Peoples R China Shanghai Sheshan Natl Geophys Observ, Shanghai, Peoples R China |
| Keywords | SPECTRAL-ELEMENT SIMULATIONS SEISMIC-WAVE PROPAGATION TELESEISMIC P-WAVES GROUND-MOTION SURFACE-TOPOGRAPHY CRUSTAL STRUCTURE STRUCTURE BENEATH TIBETAN PLATEAU KUNLUN FAULT DEFORMATION |
| Issue Date | May-2022 |
| Publisher | JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH |
| Abstract | With dense nodal seismic arrays growing rapidly, receiver function (RF) imaging has revealed unprecedented small-scale features. However, whether these fine signals represent real intra-crustal structures needs to be verified. In this study, we take the RF profiles recorded by a dense array in Ruoergai basin in northeastern Tibet as an example and demonstrate that continuous dipping phases in receiver functions (RFs) could be generated from the interference between the incoming P-wave and dramatic topographic variations. Full-waveform modeling illustrates that when an incident P-wave encounters a topographic peak, it can induce scattered P- and Rayleigh waves that propagate in backward and forward directions, consistent with the observations. The scattered Rayleigh waves exhibit a cosine radiation pattern in R-components, which explains the azimuthal-dependent observation of dipping phases in RF profiles. We then propose a two-step separation method to suppress the continuous topographic scattered phases in RF imaging, which involves a time-domain adaptive matched filtering and a curvelet-based separation. The resulting common conversion point (CCP) images show that the method can effectively suppress the continuous scattered phases induced by topography. CCP images exhibit flat intra-crustal layers, suggesting a decoupled deformation style in the upper and lower crust in NE Tibet. The upper crustal layer may represent the basement of the decollement layer, and the intermittent lower crustal interfaces are likely to indicate the partial melt within the crustal channel flow. The separation method is applicable for dense nodal array RF imaging to reveal reliable, detailed intra-crustal structures in tectonically active regions that developed dramatic topography. |
| URI | http://hdl.handle.net/20.500.11897/646709 |
| ISSN | 2169-9313 |
| DOI | 10.1029/2021JB023683 |
| Indexed | SCI(E) |
| Appears in Collections: | 地球与空间科学学院 |
