Upcoming Colloquium Series Speakers

Friday April 6, 2018 - 3:30-4:30PM - BGS 0153

Dr. Quentin Williams

COMPRES Speaker, Distinguished Professor and Associate Vice Chancellor for Research, Earth and Planetary Sciences, University of California Santa Cruz

Title: "The Core-Mantle Boundary: The Other Planetary Boundary That Matters"

Abstract

The changes in density and temperature across the core-mantle boundary region are the largest within Earth, exceeding those at Earth’s surface and within its lithosphere. As with the uppermost 200-ish km of the planet, the bottom-most few hundred km of Earth’s silicate mantle are extraordinarily structurally complex, befitting its role as the region through which much of the heat that drives mantle flow (and hence plate tectonics) is transmitted from the core to the mantle. I’ll describe the physical origins and experimental constraints on the peculiar features observed seismically in this region, including anomalous velocity gradients, ultra-low velocity zones (ULVZ’s) and large, continent-sized low shear wave-velocity provinces (LLSVP’s). The dynamic role of the core-mantle boundary in possibly being both the cradle from whence hotspots emerge and the home where slabs go to die will also be discussed.

Biography

Quentin Williams got his Bachelor’s degree in chemistry from Princeton, and his Ph.D. in geology at UC Berkeley. From 1988-91, he was a research scientist in the Institute of Tectonics at UC Santa Cruz; and from ’91 to the present, he’s been on the faculty at UCSC, currently as a Distinguished Professor, as well as the Associate Vice Chancellor for Research. He was an NSF Presidential Faculty Fellow (the predecessor of the PECASE program), and has received the Macelwane Medal of the American Geophysical Union and the Mineralogical Society of America Award. He works on a broad suite of problems related to the interiors of the Earth and planets, including collaborating with a suite of seismologists, geochemists and geodynamicists.