Community Models of Mantle P-wave Heterogeneity Beneath North America From Multiscale Travel-time Tomography Using Transportable Array Data
As USArray peregrinates across the western United States, the volumes of data it produces offer unique opportunities for seismic imaging. Constraining structures on a range of length scales and their physical and chemical causes is a prerequisite for understanding the relationship between near surface and deeper mantle processes. We produce 3-D models of P-wavespeed variations in the mantle from linearized inversion of travel time residuals from USArray combined with the global EHB catalog. We perform global inversions, but an adaptable parameterization enhances resolution in regions where more data are available. This adaptability allows us to create an internally consistent model while at the same time reaching a resolution in the western United States nearly equivalent to that of regional tomography studies. The addition of USArray data results in a significant improvement of spatial resolution of upper mantle structure beneath the western United States. This will help us understand, for example, the structural transitions from the central craton to the tectonic domains further west, the deep structure of the Cascadia subduction zone, and the relationship between the Yellowstone hotspot and processes deeper in the mantle. Model updates will be made available to the community and will also be useful as starting models for higher resolution wave equation tomography studies.
AGU Fall Meeting Abstracts
- Pub Date:
- December 2007
- 7270 Tomography (6982;