Earth and Planetary Sciences Event Calendar

Unless noted, all listed events are open to the general public.

Wednesday Seminar in Geology: GEL 190/290
Seminars are scheduled for Wednesday afternoon at 4:00 PM. Additional optional seminars that may be included as part of the Geology 190 series may be scheduled at other times.

Friday Lunch Seminar: "A Geology tradition since the Phanerozoic!"
Fridays at noon. Students and faculty give informal lectures on research, travel, or other interests.

Campus map: Earth & Physical Sciences Building | Roessler Hall

submit an event to the department calendar (restricted access)

Wednesday, November 20th, 2019, Wednesday Seminar
4:10 PM, 55 Roessler
Consequences of the Cambrian (or Why Humans Don’t Regenerate Their Heads -- Dr. David Gold, UC Davis

The Cambrian “explosion” (~541 million years ago) is the first major event in the animal fossil record, with many animal groups appearing within a relatively brief geological window. In this talk, I will briefly review how scientists have sought to understand this phenomenon. New insights from genetic data and the fossil record suggest that the “explosion” is not as explosive as originally thought, and can likely be explained through standard Darwinian processes combined with changes in environment and geochemistry. I will then turn this question around; instead of focusing on the cause of the explosion I ask why we can recognize living animal groups in half-billion-year-old fossils. I argue that the answer lies in the power that biological constraint plays on the evolution of animal life. This hypothesis can help explain differences between animal groups in basic biological processes, including aging and regeneration. In this regard, the consequences of the Cambrian “explosion” may prove more intriguing than its cause.

Friday, November 22nd, 2019, Friday Lunch Seminar
12:10 PM, 1348 Earth and Physical Sciences
Earth is the Globe: Adventures in Scientific Research and Engagement -- by EPS Graduate Students, UC Davis

As Earth scientists, we follow important research questions around the globe through fieldwork and collaborations. Come hear 15 minute highlights of internationally engaged research from students, postdocs, and researchers from the Department of Earth and Planetary Sciences. We promise stimulating ideas, beautiful images, and engaging stories from Africa, the Americas, Antarctica, Asia, Greenland, and New Zealand.

Wednesday, December 4th, 2019, Wednesday Seminar
4:10 PM, 55 Roessler
Slow slip events on the Southern San Andreas Fault -- Dr. Yuri Fialko, UC San Diego

A number of active continental strike-slip faults are associated with geodetically detectable shallow creep, while other faults (or other sections of the same fault) appear to be locked all the way to the surface over the interseismic period. Traditional interpretations of shallow creep in terms of velocity-strengthening friction in the uppermost crust predict that shallow creep should occur at a quasi-constant rate throughout much of the earthquake cycle. However, observations reveal increasingly complex time-dependent slip histories that include quasi-steady creep and triggered as well as spontaneous accelerated slip events. I will review existing evidence for unsteady shallow creep, and present new observations a recent slow slip event on the Southern San Andreas fault (SSAF). The SSAF is the only section of the San Andreas fault that hasn't produced a large earthquake in historic times, and is believed to be in the late phase of the earthquake cycle. The timing of the slow slip event on the SSAF suggests that it was was dynamically triggered by the 2017 M8.2 Chiapas (Mexico) earthquake that occurred 3000 km away. Geodetic and geologic observations indicate that surface slip on the order of 10 mm occurred on a 40-km-long section of the SSAF between the Mecca Hills and Bombay Beach, starting minutes after the Chiapas earthquake and continuing for more than a year. Both the magnitude and the depth extent of creep vary along strike. I will present a high-resolution map of surface displacements derived from the Sentinel-1 Interferometric Synthetic Aperture Radar (InSAR) acquisitions from different lines of sight. InSAR-derived displacements are in good agreement with the creepmeter data and field mapping of surface offsets. I will also present results of numerical modeling of shallow creep on a strike-slip fault, and show that the observed behavior can be explained in the framework of the rate and state friction. I will discuss implications from the observations and numerical models for the frictional properties of the top few kilometers of the upper crust, and the long-term fault operation.

Friday, December 6th, 2019, Friday Lunch Seminar
12:10 PM, 1348 Earth and Physical Sciences
AGU Practice Talks - Special 2-hour Seminar  -- by EPS Scientists, UC Davis

Anyone from the EPS Department who is giving a talk at AGU and would like a chance to practice and get some feedback before the meeting can sign-up to give a talk. We will follow strict time rules and ask the audience to give feedback on a written paper (or separately). This special Lunch Seminar will be followed by a poster session, for those presenting posters instead of talks, and the department end-of-fall gathering.