GPS Event Calendar

"Grains versus plates: the competition between tectonic and sedimentary processes in creating topography"
Chris Paola - University of Minnesota
Abstract:

Earth's topography generally represents the outcome of a contest between creation of relief by tectonics and destruction, or filling, of relief by surface processes. We'll review studies our group has done over many years in which we attempt to parameterize the outcome of this competition in terms of tectonic versus sedimentary rates, based mostly on lab experiments with imposed deformation fields. A prevailing theme is the importance of dimensionless numbers involving tectonic versus sedimentary mass input rates.

"The ongoing Fagradalsfjall eruption in Iceland:  What was so special about precursors and ground deformation preceding the eruption"
Freysteinn Sigmundsson - Nordic Volcanological Centre, University of Iceland
via Zoom 4:00 PM (Pacific Time)

"TBD"
Kim Blisniuk - San Jose State University

"TBD"
Todd Ehlers - Universität Tübingen

"TBD"
TBD

"TBD"
Rosemary Knight - Stanford University
via Zoom 4:00 PM (Pacific Time)

"TBD"
Shaily Rahman - University of Colorado, Boulder

"TBD"
Xi Zhang - UC Santa Cruz

"TBD"
Seulgi Moon - UCLA

"TBD"
Patricia Persaud - Louisiana State University
via Zoom 12:00 PM (Pacific Time)

"Connecting seismicity patterns to earthquake forecasting and hazard"

Dr. Morgan Page (USGS Pasadena Office)

ABSTRACT:

Much of what we know about earthquake predictability comes from observations of seismicity – observations that are limited in time and primarily composed of small earthquakes. The principal scaling laws borne out of seismicity studies do an excellent job of describing the first-order characteristics of observed earthquake patterns, and yet we can still see another layer of complexity beyond these broad-brush laws if we sort and stack data appropriately. In particular I will discuss "beyond-ETAS" effects for aftershock locations and sizes. Understanding how to scale up our limited observations to longer time periods and larger earthquakes is of particular importance for seismic hazard models. I discuss how insights from seismicity can improve UCERF-style hazard models that attempt to combine long-term fault-based information and more short-term seismicity information into a single earthquake forecasting model.

"Quantification and mechanical control of fault slip: insights from physics based models"
Pierre Dublanchet (MINES Paris Tech)
ABSTRACT:
Tectonic faults release elastic energy supplied by plate motion by a large spectrum of slip phenomena, ranging from continuous slow (cm/yr) creep to fast (m/s) slip events known as earthquakes. Decades of geodetical and seismological monitoring of fault slip has revealed in many active areas complex successions of interacting fault slip events at different scales. Despite this apparent complexity, fault slip seems to obey rather simple scalings and statistical laws (Gutenberg-Richter magnitude-frequency distribution, Omori law, moment-duration scaling). Another important discovery about fault slip events is the ubiquitous imbrication between slow aseismic slip, radiative events such as earthquakes and fluid flow. The important role of fluids in fault slip processes is in particular suggested by the numerous examples of seismicity induced by reservoir exploitation. Nevertheless, we currently lack important aspects of the mechanical control on fault slip. First, because the mechanisms triggering fault slip (tectonic stress accumulation, deep pore pressure variations, stress redistributions between faults, aseismic slip) are poorly quantified. Then, because of our partial knowledge of the physical laws controlling fault slip, generally upscaled from laboratory experiments. My research activities aim at improving our understanding of the mechanical control of slip by the use of fault models coupling elasticity, friction and fluids.

"Gas Planet Seismology and Cooling"

Members of the Ph.D. examining committee are: Andy Ingersoll (chair), Dave Stevenson, Konstantin Batygin (thesis co-advisors), Jim Fuller