Seismic Azimuthal Anisotropy Beneath the Alaska Subduction Zone
AbstractWe estimate depth‐dependent azimuthal anisotropy and shear wave velocity structure beneath the Alaska subduction zone by the inversion of a new Rayleigh wave dispersion dataset from 8 to 85 s period. We present a layered azimuthal anisotropy model from the forearc region offshore to the subd...
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
Wiley
2024-07-01
|
| Series: | Geophysical Research Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1029/2024GL109758 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1849321285237080064 |
|---|---|
| author | Chuanming Liu Anne F. Sheehan Michael H. Ritzwoller |
| author_facet | Chuanming Liu Anne F. Sheehan Michael H. Ritzwoller |
| author_sort | Chuanming Liu |
| collection | DOAJ |
| description | AbstractWe estimate depth‐dependent azimuthal anisotropy and shear wave velocity structure beneath the Alaska subduction zone by the inversion of a new Rayleigh wave dispersion dataset from 8 to 85 s period. We present a layered azimuthal anisotropy model from the forearc region offshore to the subduction zone onshore. In the forearc crust, we find a trench‐parallel pattern in the Semidi and Kodiak segments, while a trench‐oblique pattern is observed in the Shumagins segment. These fast directions agree well with the orientations of local faults. Within the subducted slab, a dichotomous pattern of anisotropy fast axes is observed along the trench, which is consistent with the orientation of fossil anisotropy generated at the mid‐ocean ridges of the Pacific‐Vancouver and Kula‐Pacific plates that is preserved during subduction. Beneath the subducted slab, a trench‐parallel pattern is observed near the trench, which may indicate the direction of mantle flow. |
| format | Article |
| id | doaj-art-e5d82138422e4a4aaf9dd87b130a849f |
| institution | Kabale University |
| issn | 0094-8276 1944-8007 |
| language | English |
| publishDate | 2024-07-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geophysical Research Letters |
| spelling | doaj-art-e5d82138422e4a4aaf9dd87b130a849f2025-08-20T03:49:46ZengWileyGeophysical Research Letters0094-82761944-80072024-07-015114n/an/a10.1029/2024GL109758Seismic Azimuthal Anisotropy Beneath the Alaska Subduction ZoneChuanming Liu0Anne F. Sheehan1Michael H. Ritzwoller2Institute for Geophysics & Department of Earth and Planetary SciencesJackson School of GeosciencesThe University of Texas at AustinAustinTXUSACooperative Institute for Research in Environmental Sciences and Department of Geological SciencesUniversity of Colorado BoulderBoulderCOUSADepartment of PhysicsUniversity of Colorado BoulderBoulderCOUSAAbstractWe estimate depth‐dependent azimuthal anisotropy and shear wave velocity structure beneath the Alaska subduction zone by the inversion of a new Rayleigh wave dispersion dataset from 8 to 85 s period. We present a layered azimuthal anisotropy model from the forearc region offshore to the subduction zone onshore. In the forearc crust, we find a trench‐parallel pattern in the Semidi and Kodiak segments, while a trench‐oblique pattern is observed in the Shumagins segment. These fast directions agree well with the orientations of local faults. Within the subducted slab, a dichotomous pattern of anisotropy fast axes is observed along the trench, which is consistent with the orientation of fossil anisotropy generated at the mid‐ocean ridges of the Pacific‐Vancouver and Kula‐Pacific plates that is preserved during subduction. Beneath the subducted slab, a trench‐parallel pattern is observed near the trench, which may indicate the direction of mantle flow.https://doi.org/10.1029/2024GL109758seismic anisotropysurface wave tomographyAlaska subduction zoneazimuthal anisotropysurface wavealeutian subduction zone |
| spellingShingle | Chuanming Liu Anne F. Sheehan Michael H. Ritzwoller Seismic Azimuthal Anisotropy Beneath the Alaska Subduction Zone Geophysical Research Letters seismic anisotropy surface wave tomography Alaska subduction zone azimuthal anisotropy surface wave aleutian subduction zone |
| title | Seismic Azimuthal Anisotropy Beneath the Alaska Subduction Zone |
| title_full | Seismic Azimuthal Anisotropy Beneath the Alaska Subduction Zone |
| title_fullStr | Seismic Azimuthal Anisotropy Beneath the Alaska Subduction Zone |
| title_full_unstemmed | Seismic Azimuthal Anisotropy Beneath the Alaska Subduction Zone |
| title_short | Seismic Azimuthal Anisotropy Beneath the Alaska Subduction Zone |
| title_sort | seismic azimuthal anisotropy beneath the alaska subduction zone |
| topic | seismic anisotropy surface wave tomography Alaska subduction zone azimuthal anisotropy surface wave aleutian subduction zone |
| url | https://doi.org/10.1029/2024GL109758 |
| work_keys_str_mv | AT chuanmingliu seismicazimuthalanisotropybeneaththealaskasubductionzone AT annefsheehan seismicazimuthalanisotropybeneaththealaskasubductionzone AT michaelhritzwoller seismicazimuthalanisotropybeneaththealaskasubductionzone |