How Do Plates Evolve?
How Do Plates Evolve?
Credit:
Gene Humphreys, University of Oregon/IRIS Consortium
Description
P-wave velocity structure near the base of the western U.S., from Schmandt and Humphreys (2010). Velocity variations this great reflect temperature variations. Such structure indicates that vertical flow velocities create temperature variations at rates greater than are healed by conduction, i.e., the region is experiencing vigorous small-scale convection. High-resolution imaging at this scale has only been possible since the deployment of EarthScope’s USArray.
References
Carlson, R.W., A.J. Irving, and B.C. Hearn Jr., in Gurney, J.J., J.L. Gurney, M.D. Pascoe, and S.H. Richardson, eds., Proceedings of the 7th International Kimberlite Conference, Vol. 1: Cape Town, Red Roof Design, p. 90-98, 1999.
DeCelles, P.G., M.N. Ducea, P. Kapp and G. Zandt, Cyclicity in cordilleran orogenic systems, Nature Geoscience, v. 2, doi:10.1038/ngeo469, 2009.
Schmandt, B., and E. Humphreys, Complex subduction and small-scale convection revealed by body-wave tomography of the western United States upper mantle, Earth Planet. Sci. Lett., doi:10.1016/j.epsl.2010.06.047, 2010.
Date Taken: September 29, 2010
Photographer / Contributor: Gene Humphreys
