Affiliation:
1. Department of Earth Sciences Faculty of Mathematical & Physical Sciences University College London London UK
2. CERIS Instituto Superior Técnico Universidade de Lisboa Lisboa Portugal
3. The Geological Survey of Israel Jerusalem Israel
4. Research School of Earth Sciences Australian National University Canberra Australia
Abstract
AbstractSurface wave amplification measurements have narrower depth sensitivity when compared to more traditional seismic observables such as surface wave dispersion measurements. In particular, Love wave amplification measurements have the advantage of strong sensitivity to the crust. For the first time, we explore the potential of Love wave amplification measurements to image crustal velocity in the western U.S. The effects of overtone interference, radial anisotropy and Moho depth are all explored. Consequently, we present SWUS‐crust, a three‐dimensional shear‐wave velocity model of crustal structure in the western U.S. We use Rayleigh wave amplification measurements in the period range of 38–114 s, along with Love wave amplification measurements in the period range of 38–62 s. We jointly invert over 6,400 multi‐frequency measurements using the Monte‐Carlo based Neighborhood Algorithm, which allows for uncertainty quantification. SWUS‐crust confirms several features observed in previous models, such as high‐velocity anomalies beneath the Columbia basin and low‐velocity anomalies beneath the Basin and Range province. Certain features are sharpened in our model, such as the northern border of the High‐Lava Plains in southern Oregon in the middle crust.
Funder
Natural Environment Research Council
Publisher
American Geophysical Union (AGU)
Subject
Space and Planetary Science,Earth and Planetary Sciences (miscellaneous),Geochemistry and Petrology,Geophysics