Winter 2020

Fridays at 12:00 PM

E&MS A340

January 10, 2020

Speaker: Roland Burgmann, UC Berkeley

Title: Slow Fault Slip


January 17, 2020



January 24, 2020

Speaker: Lars Borg, LLNL

Title: Isotopic Constraints for the Formation of the Moon


January 31, 2020

Speaker: Simon Lock, Caltech

Title: The origin of the Moon within a terrestrial synestia

Abstract: The giant impact hypothesis has been the leading theory for the origin of the Moon for decades, but current models struggle to explain the Moon's composition and isotopic similarity with Earth. I will present a new lunar origin model based on the discovery that high‐energy, high‐angular‐momentum giant impacts can create a previously unrecognized type of planetary structure, named a synestia. Using simulations of cooling synestias combined with dynamic, thermodynamic, and geochemical calculations, I will show that satellite formation from a synestia can produce the principal features of our Moon. Cooling of the synestia drives condensation, producing moonlets that orbit within the synestia, surrounded by tens of bars of bulk silicate Earth vapor. Moonlets equilibrate with bulk silicate Earth vapor at the temperature of silicate vaporization and the pressure of the structure, establishing the lunar isotopic and chemical composition. Eventually, the cooling synestia recedes within the lunar orbit, terminating the main stage of lunar accretion. Our model shifts the paradigm for lunar origin from specifying a certain impact scenario to achieving a Moon‐forming synestia.


February 7, 2020

Speaker: Alexander Sehlke, NASA

Title: The Anatomy of the Blue Dragon: Correlations between Lava Flow Morphology and Physical Properties


February 14, 2020

Speaker: Will Steinhardt, UCSC

Title: The Rules of Roughness: An Experimental Investigation into the Origins of Brittle Fracture Complexity

February 21, 2020

Speaker: Felipe Gonzalez-Cataldo, UC Berkeley

Title: Understanding Planetary Interiors from the Atomic Interactions of Materials


February 28, 2020

Speaker: Camilla Cattania, Stanford

Title: Fracture mechanics insights into earthquake cycles and foreshock sequences


March 6, 2020

Speaker: Kathryn Steakley, NASA Ames Research Center

Title: Testing the Impact Hypothesis for Warming Early Mars


March 13, 2020

Speaker: Danny Brothers, USGS