Group B, Poster #262, SCEC Community Models (CXM)
Characterizing the lithosphere-asthenosphere boundary in southern and eastern California
Poster Image:
Poster Presentation
2022 SCEC Annual Meeting, Poster #262, SCEC Contribution #12228 VIEW PDF
ferences in observed lithospheric thickness estimates exist between methods may help us to better understand the uncertainties in the SCEC community models.
To better understand how constraints on lithospheric thickness vary between receiver functions (RF) and surface wave tomography, we first calculated Sp receiver functions using data from over 1000 broadband stations from more than 50 temporary and permanent networks from across the southwestern U.S. We find the average depth of the lithosphere-asthenosphere boundary (LAB) phase across our study area to be 65.3 km, but absolute depths vary from roughly 30 to 100 km. Here, we focus our presentation on the depth of the LAB phase beneath southern and eastern California, divided into sections based on the physiographic boundaries of Fenneman and Johnson (1946) in order to understand the potential relationship between the depth of the LAB phase and tectonics.
Lastly, we compare depth picks of the LAB from Sp RF to the surface wave tomography model of Shen and Ritzwoller (2016) to assess if, and to what extent, our interpretation of the LAB correlates with features of their model. Across the study area, roughly 80% of the RF LAB depth picks fall within the depth range of negative velocity phase determined from tomography, suggesting a coarse agreement between methods in most locations. However, no correlation exists between RF LAB depth and other aspects of the tomography model, such as the depth of the maximum negative velocity gradient, or the maximum or minimum velocity depths. Ongoing work is being done to better understand the differences in seismic constraints of the LAB and resulting mantle structure, which can then be used to improve the CTM and CRM.
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To better understand how constraints on lithospheric thickness vary between receiver functions (RF) and surface wave tomography, we first calculated Sp receiver functions using data from over 1000 broadband stations from more than 50 temporary and permanent networks from across the southwestern U.S. We find the average depth of the lithosphere-asthenosphere boundary (LAB) phase across our study area to be 65.3 km, but absolute depths vary from roughly 30 to 100 km. Here, we focus our presentation on the depth of the LAB phase beneath southern and eastern California, divided into sections based on the physiographic boundaries of Fenneman and Johnson (1946) in order to understand the potential relationship between the depth of the LAB phase and tectonics.
Lastly, we compare depth picks of the LAB from Sp RF to the surface wave tomography model of Shen and Ritzwoller (2016) to assess if, and to what extent, our interpretation of the LAB correlates with features of their model. Across the study area, roughly 80% of the RF LAB depth picks fall within the depth range of negative velocity phase determined from tomography, suggesting a coarse agreement between methods in most locations. However, no correlation exists between RF LAB depth and other aspects of the tomography model, such as the depth of the maximum negative velocity gradient, or the maximum or minimum velocity depths. Ongoing work is being done to better understand the differences in seismic constraints of the LAB and resulting mantle structure, which can then be used to improve the CTM and CRM.
SHOW MORE
Citation: Shallon, B., & Ford, H. A. (2022, 09). Characterizing the lithosphere-asthenosphere boundary in southern and eastern California. Poster Presentation at 2022 SCEC Annual Meeting.
Relevant SCEC Themes:
Community Models
