Crustal Deformation in Southern California Constrained by Radial Anisotropy From Ambient Noise Adjoint Tomography

Details

• Journal Title:
  Geophysical Research Letters
• Personal Author:
  Wang, Kai ; Jiang, Chengxin ; Yang, Yingjie ; Schulte‐Pelkum, Vera ; Liu, Qinya
• NOAA Program & Office:
  CIRES (Cooperative Institute for Research in Environmental Sciences)
• Description:
  We build a new radially anisotropic shear wave velocity model of Southern California based on ambient noise adjoint tomography to investigate crustal deformation associated with Cenozoic evolution of the Paci fic‐North American plate boundary. Pervasive positive radial anisotropy (4%) is observed in the crust east of the San Andreas Fault (SAF), attributed to subhorizontal alignment of mica/amphibolefoliation planes resulting from signi ficant crustal extension. Substantial negative anisotropy (6%) is revealed in the middle/lower crust west of the SAF, where high shear wave speeds are also observed. The negative anisotropy could result from steeply dipping amphibole schists in a shear zone developed during Laramideflat slab subduction. Alternatively, it could be caused by the crystal preferred orientation (CPO) of plagioclase, whose fast axis aligns orthogonally to a presumed subhorizontal foliation. The latter new
• Keywords:
  General Earth And Planetary Sciences Geophysics General Earth And Planetary Sciences General Earth And Planetary Sciences
• Source:
  Geophysical Research Letters, 47(12)
• DOI:
  https://doi.org/10.1029/2020gl088580
• ISSN:
  0094-8276 ; 1944-8007
• Format:
  PDF
• Publisher:
  American Geophysical Union (AGU)
• Document Type:
  Journal Article
• Rights Information:
  Other
• Compliance:
  Library
• Main Document Checksum:
  urn:sha256:c42034b2012c3470ddd71e51e81e5312b8444bc3217d381d3da5e05978a28929
• Download URL:
  https://repository.library.noaa.gov/view/noaa/54981/noaa_54981_DS1.pdf
• File Type:
  [PDF - 8.68 MB ]