University of Connecticut

Events Calendar

Graduate Student Seminar

Friday, September 27, 2019
12:15pm – 1:15pm

Storrs Campus
GS-119

Prof. V. Cormier, Department of Physics, University of Connecticut

Scattered Elastic Waves Reveal Small-scale Planetary Structure

Planetary structures on the order of a wavelength (1-10 km) of the elastic waves radiated by earthquakes have observable and predictable effects on recorded seismograms expressed as energy scattered into different directions and time windows. I will describe two applications that exploit observations of the scattered seismic wavefield to determine the heterogeneity spectrum of Earth’s deep interior. Small-scale structures in Earth’s mantle affects the coherence of seismic body waves recorded by surface arrays of seismometers through focusing, defocusing, and scattering. In one application, we are extending theories of forward wave scattering to invert the amplitude and travel time coherence of seismic waves to reveal the solid-solid phase changes predicted for the lattices of silicate minerals composing Earth’s mantle. In another application, we use a radiative transport theory to show how the heterogeneity spectrum and variations in the thickness of Earth’s crust can affect the amplitude of S body waves trapped in a crustal waveguide. These crust-trapped S waves are better excited by earthquakes than explosions; hence are useful for nuclear test monitoring, but are sometimes blocked by crustal thickness variations.

Contact:

Prof. V. Kharchenko

Physics Department (primary), College of Liberal Arts and Sciences, UConn Master Calendar

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