Spring 2016

Spring 2016

Tuesday Afternoons at 4:00 PM
Natural Science Annex 101



March 29, 2016

Speaker: Mike Lamb, CalTech

Title: Wildfires, debris flows, and the mechanics of steep bedrock landscapes

Hosts: Jack Conrad


April 5, 2016

Speaker: Jean Braun, UC Berkeley

Title: Links between surface processes and mantle flow or how fluvial erosion and chemical weathering combine to erode dynamic topography

Hosts: Ricardo Garza Giron


April 12, 2016

Speaker: Vena Chu, UC Berkeley

Title: Hydrologic Dynamics of the Greenland Ice Sheet

Hosts: Dustin Harper


April 19, 2016

Speaker: Jonathan Fortney, UCSC

Title: Toward an Understanding of Exoplanetary Composition

Abstract:

Nearly all of the narratives about understanding the composition of planets come from our understanding of the solar system. However, this is a terribly small sample size.  The era of exoplanet characterization allows us to understand planets with a tremendously larger scope. In this talk I will cover several topics that shed light on planetary composition.  In the realm of transiting planets, planetary structure models, compared to observations from the Kepler telescope and ground-based surveys, show our solar system’s population of rocky planets is potentially unusual since they lack thick hydrogen atmospheres. However, our two gas giants, Jupiter and Saturn, fit well within the population of transiting giant exoplanets, in that all these planets show similar enrichments in "metals" (elements heavier than He) compared to their parent star’s composition. Next, we  are obtaining spectra of transiting planet atmospheres with Hubble to constrain atmospheric molecular abundances, which also point toward metal-enrichment for gas giants.  Finally, we are developing new theoretical tools to extract constraints on atmospheric abundances from the spectra of brown dwarfs and giant planets to look for composition clues that distinguish these two populations. As a whole these advances will yield fundamentally new insights on planetary formation and evolution.

Abstract: Hosts: Allison Pfeiffer


April 26, 2016

Speaker: John Chiang, UC Berkeley

Title: Role of Seasonal Transitions and Westerly Jets in East Asian Paleoclimate

Hosts: Esther Adelstein


May 3, 2016

Speaker: Sandra Kirtland Turner, UC Riverside

Title: Novel constraints on carbon release rates across Eocene warming events

Hosts: Michele Markowitz


May 10, 2016

Speaker: Matthew Seigfried, Scripps

Title: Episodic hydrology, episodic ice streams: Unraveling the impact of active subglacial lakes in Antarctica

Abstract: In the past decade, the Antarctic subglacial environment has proven to be a dynamic system with the ability to profoundly influence both local and far-field biology, geochemistry, oceanography, and ice physics. However, detailed observations of subglacial processes, which are necessary to constrain predictive models of ice sheet evolution, remain sparse, in part due to the difficulty of collecting spatially-extensive, time-resolved datasets in Antarctica. Using a combination of ground-based, airborne, and satellite observations, I will present new results from Whillans Ice Stream, West Antarctica, and Slessor Glacier, East Antarctica, to connect non-steady-state subglacial hydrology to large, episodic fluctuations in ice velocity. These changes in ice dynamics occur on timescales shorter than previously observed, with potential consequences on our observational strategies and estimates of ice sheet mass balance. Only with longer records of active subglacial hydrology and better insight into its relationship with ice dynamics can we begin to understand the important spatial and temporal scales of ice-water interaction at the basal interface and unravel the role of the co-evolving subglacial-glacial system within the framework of large-scale ice sheet variability.

Hosts:Adrienne Grant


May 17, 2016

Speaker: Noel Heim, Stanford

Title: Considering the Full House of Variation: Revisiting Gould’s Hypothesis on the Evolution of Size & Complexity

Hosts: JP O'Brien


May 24, 2016

Speaker: Aradhna Tripati, UCLA

Title: Glacial climate from clumped isotope thermometry

Hosts: Tracey Conrad


May 31, 2015

Speaker: Sam Dupont, UC Berkeley

Title: What do we need to tackle ocean acidification? An eco-physiologist view

Hosts: Nicholas Zube