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GPS Event Calendar

Seminars & Events

Week of August 3, 2020
Kyle Metcalfe Thesis Defense
1:00 pm
GPS Yuk Lunch Seminar
12:00pm to 1:00pm
Seismo Lab Seminar
9:00 am to 10:00 am
Physical Oceanography Group Meeting
12:00pm to 1:00pm
Geoclub Seminar Series
4:00 pm to 5:00 pm

DIX Planetary Science Seminar

Will resume for Fall term

Environmental Science and Engineering Seminar

Will resume for Fall term

Geoclub Seminar Series

Thursdays from 4:00pm to 5:00pm
For more information, please contact: Dustin Morris

"What drove the Lunar dynamo?"

Benjamin Weiss Professor of Planetary Sciences Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology

Abstract: Although the Moon today has no global magnetic field, paleomagnetic measurements of Apollo samples indicate the existence of an ancient field from at least 4.25 to 1.92 billion years ago. It has been proposed that the paleofield was generated by a core dynamo. However, the paleofield's apparent high intensity and longevity are major challenges to current theory. Three key difficulties have been that the paleofield intensity has been poorly constrained, while the paleofield's lifetime and direction have been essentially unknown. To address this, I describe three key new types of paleomagnetic measurements. First, enabled by our new controlled oxygen fugacity thermal demagnetization system, I report some of the first accurate lunar paleointensity measurements. Second, I present young paleointensities to constrain the end of the field's lifetime. Finally, I report a robust constraint on the field's paleodirection from Apollo 17 basalt flows (see photo below). The data collectively support the existence of an intense early dynamo powered by an unusually energetic mechanism like precession, followed by a weaker long-lived dynamo perhaps powered by core crystallization. The paleodirectional data are consistent with but do not require a Moon-centric axial dipole geometry like that of the Earth.

GPS Yuk Lunch Seminar

Wednesdays from 12:00pm to 1:00pm
For more information, please contact: Danica Adams

Physical Oceanography Group Meeting

Fridays from 12:00pm to 1:00pm
All welcome, contact Andy Thompson for details, andrewt@caltech.edu

Seismo Lab Seminar

Thursdays from 9:00 am to 10:00 am
For more information, please contact Seismo Seminar Committee.

Thesis Defense Seminars

For more information, please contact Julie Lee; jlee@gps.caltech.edu

Kyle Metcalfe - August 3, 2020 1:00 PM

"Symbiotic Diversity and Mineral-Associated Microbial Ecology in Marine Microbiomes"

Members of the Ph.D. examining committee are: Jared Leadbetter (chair), Victoria Orphan (thesis adviser), Woody Fischer, George Rossman

Zoom link:


Meeting ID: 737 293 8281