Debra Humphreys Association of American Colleges & Universities humphreys@aacu aacu
Schmandt and Humphreys, 2011
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Outstanding questions, controversial interpretations, and enigmatic observations: A seismic perspective Schmandt and Humphreys, 2011 - Tomographic velocity models - Upper mantle discontinuity structure - Anisotropic structure of lithosphere
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Outstanding questions, controversial interpretations, and enigmatic observations: A seismic perspective. Schmandt and Humphreys, 2011. - Tomographic velocity models - Upper mantle discontinuity structure - Anisotropic structure of lithosphere. - PowerPoint PPT Presentation
Transcript of Schmandt and Humphreys, 2011
Outstanding questions, controversial interpretations, and enigmatic observations: A seismic perspective
Schmandt and Humphreys, 2011
- Tomographic velocity models - Upper mantle discontinuity structure - Anisotropic structure of lithosphere
Seismic tomography models from USArray (and other) data
Becker, 2012; see alsoPavlis et al., 2012
Berkeley model Oregon model ASU/Carnegie model
Seismic tomography models from USArray (and other) data
Becker, 2012Berkeley model Oregon model ASU/Carnegie model
Seismic tomography models from USArray (and other) data
Becker, 2012
Models for W. US are similar, but amplitudes different
Seismic tomography models from USArray (and other) data
Schmandt and Humphreys, 2011
Seismic tomography models from USArray (and other) data
Obrebski et al., 2011
Seismic tomography models from USArray data: surface wave/ambient noise models
Wagner et al., 2012
Combining seismic tomography & MT
Kelbert et al., 2012
Seismic tomography models: looking ahead
Burdick et al., 2012
Seismic discontinuity structure of the lithosphere
Abt et al., 2010
Seismic discontinuity structure of the lithosphere
Lekic et al., 2011
Seismic anisotropy of the lithosphere: a relic of past deformation processes
Yuan et al., 2011
Seismic anisotropy of the lithosphere: a relic of past deformation processes?
Wagner et al., 2012
Summary• Seismic tomography models derived from USArray data in the
western US show a remarkable degree of robust, well-resolved heterogeneity on small spatial scales.
• The interpretation of many of the features in tomography models is still open to exploration/debate.
• Resistivity models obtained from the MT TA can provide constraints complementary to those obtained from seismic velocity models; joint interpretation can shed light on physical processes in crust and upper mantle.
• Several new and exciting results relating to the discontinuity structure of the North American lithosphere.• Nature of LAB? Is the asthenosphere wet/partially melted?• Nature of MLD?
• Anisotropic structure of lithosphere reflects past episodes of deformation. To what extent are these structures reflected in resistivity structure?
