Francis Nimmo, Department of Earth and Planetary Sciences, University of California Santa Cruz, "What's Going on at Enceladus?
Abstract: The Cassini spacecraft revealed that Enceladus, a small icy moon of Saturn, is unexpectedly interesting. In particular, it is one of only four solar system bodies known to be geologically active: it has south polar geysers spewing water vapour hundreds of km into space. In this talk I will discuss recent theoretical work on Enceladus, focusing on three particular issues: why is it active?; does it have an ocean?; and how has it evolved? The answers are relevant to the astrobiological potential of Enceladus, and may also influence the design of future spacecraft missions.
Time:
3:00pm - 4:00pm
Location:
HGS 101
Description:
Leslie Hayden, Department of Geological Sciences, Case Western Reserve University, "Trace Element Partitioning in the Fe-S-C System: Implications for the Evolution of Planetary Cores"
Time:
1:30pm - 2:30pm
Description:
Richard Lutz, Rutgers University, "Ecology of Deep-Sea Hydrothermal Vents"
Time:
3:00pm - 4:00pm
Location:
HGS 101
Description:
Max Berkelhammer, Department of Earth Sciences, University of Southern California, TBA
Time:
7:30pm - 9:00pm
Description:
Ev Morph Seminar
Time:
1:30pm - 2:30pm
Description:
Jeffrey Andrews-Hanna, Department of Geophysics, Colorado School of Mines, "The Impact that Shaped Mars: New Views of the Crustal Structure and Tectonics of the Red Planet"
Abstract: One of the most prominent and puzzling features on Mars is its hemispheric dichotomy in topography and crustal thickness, dividing the planet into the southern highlands and northern lowlands. In recent work, we used the gravity and topography of Mars to reveal the location of the dichotomy boundary where it is buried beneath the enormous Tharsis volcanic rise. The globally continuous dichotomy boundary was then found to be elliptical in shape, with the northern lowlands bearing a striking resemblance to the much smaller giant impact basins on Mars and the Moon. This new evidence suggests that the martian dichotomy formed in a single giant impact early in the planet's history. The northern 'Borealis basin' is the largest impact basin in the solar system, covering 40% of the surface of Mars. Ongoing work now suggests that the crustal dichotomy is related to two other large-scale features on Mars: Arabia Terra and Valles Marineris. Arabia Terra is the one ancient crustal province that does not fit into the simple highlands-lowlands dichotomy. Topography and crustal thickness models suggest that Arabia Terra is a partial ring structure that formed in the moments following the impact, similar to the rings around basins on the Moon and Mars. The Valles Marineris canyons are the largest tectonic canyons in the solar system. They are now seen to lie south of and approximately parallel to the buried dichotomy boundary beneath the Tharsis volcanic rise. Volcanic loading over the buried boundary would have resulted in a focusing of stresses along the boundary, leading to the opening of the canyons. Other evidence suggests that the magnetic field and climate evolution of Mars were also strongly influenced by this dichotomy-forming impact. In short, the entire evolution of Mars and the fate of the planet may have been sealed in a single catastrophic collision early in the planet's history.
Time:
3:00pm - 4:00pm
Location:
HGS 101
Description:
Gabriel Filippelli, Center for Environmental Health, Indiana University, TBA
1:30pm» Seminar, Francis Nimmo, University of California Santa Cruz, "What's Going on at...