DeFord Lecture Series
DeFord Lecture Series Speaker Schedule
The DeFord (Technical Sessions) lecture series has been a requirement and a tradition for all graduate students since the late 1940s. Once the official venue for disseminating Department of Earth and Planetary Sciences graduate student research, the DeFord Lecture series is now the forum for lectures by distinguished visitors and members of our community. Faculty and researchers from the Jackson School have invited prestigious researchers from around the world to present a lecture in this series. This is made possible only through a series of endowments, such as those funding past Distinguished Lectures.
The list below shows all the scheduled talks this semester. If you would like to meet with any of the speakers, please contact them or their hosts directly.
DeFord Lecture Series Fall 2025 Speaker Schedule
All talks are Thursdays from 3:30-4:30 p.m. in the Boyd Auditorium (JGB 2.324). Lectures will be recorded, and most past lectures are posted on the Jackson School YouTube channel.
Sept. 4
Dr. Tim Goudge
Department of Earth and Planetary Sciences
Jackson School of Geosciences
University of Texas at Austin
Remote Sensing of Sinuous Channels in the Solar System: From Meandering Rivers to Lava Channels
Abstract: Remote sensing data provide a landscape-scale view of the surface properties of planetary bodies, and offer unique insight into a wide array of geoscience problems. In this talk I will present results from two projects that showcase how remote sensing data can be used to characterize landscape evolution on Earth and other planetary bodies. The first project focuses on use of high-frequency, high-resolution lidar topography from a UAV (uncrewed aerial vehicle) to characterize the process of bank erosion in meandering rivers. This work provides insight into when river banks erode, and the evolution from short-term stochastic to long-term average behavior. The second project looks at the geometry of bends within three distinct classes of sinuous channels formed by fluid flow: meandering rivers (Earth), supraglacial channels (Earth), and sinuous volcanic channels (the Moon). This work aims to test whether sinuous channel geometry records diagnostic aspects of the formative process, or whether it is a universal outcome of confined fluid flow.
Sept. 11
Dr. Jane Baldwin
The University of California, Irvine
The Role of Mountains in Understanding and Simulating Earth’s Climate
Sept. 18
Dr. Christine McCarthy
Lamont-Doherty Earth Observatory
Columbia University
Heat Generating Mechanisms in Ice and the Fate of Partial Melt
Sept. 25
Dr. Douwe van Hinsbergen
Utrecht University
From Plate to Mantle Tectonics: Towards 3D Kinematic Constraints on Mantle Convection
Oct. 2
Dr. Terry Plank
Lamont-Doherty Earth Observatory
Columbia University
Magma Stalling and Launching Depths beneath Active Volcanoes
Abstract: How do volcanoes prepare to erupt? Where is magma stored prior to eruption? What roles do H2O and CO2 play in launching eruptions? This talk will address these questions by examining volcanic crystals and their melt inclusions as volatile archives, and comparing to geophysical studies of magma stalling and ascent.
Oct. 9
Dr. Ian Kane
University of Manchester
Transport and Burial of Anthropogenic Pollutants in Deep-Marine Sedimentary Systems
Oct. 16
Dr. Nadja Drabon
Harvard University
Hadean zircon from South Africa: New Insights into Early Surface Environments
Oct. 23
Dr. Jeff Schragge
Colorado School of Mines
Observations from the Seafloor: Low-frequency Ambient Wavefield Seismology on Large Ocean-Bottom Nodal Arrays
Abstract: Estimating accurate Earth models for 3-D seismic imaging and full waveform inversion (FWI) remains challenging due to limited low frequencies (i.e., below 2.0 Hz) typically available from active-source air gun arrays. Ambient wavefield energy acquired on large, continuously recording nodal arrays, though, presents a potential alternative energy source for subsurface investigation. By exploiting principles of seismic interferometry in deep-water marine settings, low-frequency virtual shot gathers (VSGs) from 1.0 Hz to as low as 0.05 Hz can be generated with surface-wave events that exhibit clear sensitivity to large-scale model features including salt bodies. The estimated VSG data also exhibit surface-wave scattering events consistent with the locations and depths of shallow salt pinnacles observed in active-source velocity model reconstructions. These observations suggest an alternative pathway forward for estimating long- (and potentially shorter-)wavelength elastic models required for accurate 3-D FWI and seismic imaging analyses.
Oct. 30
Dr. Shi Joyce Sim
Georgia Institute of Technology
Dynamic Habitability: From Mid-Ocean Ridges to Europa
Abstract: Dynamic habitability is the evolving habitability of a system, e.g., Venus might not be habitable now but might have been in the past or even in the future. The essential components of life are a solvent, the right chemistry (i.e., CHNOPS), energy that can be taken advantage of and a suitable environment. In this talk, I will attempt to look at dynamic habitability from the perspective of Earth all the way to Jupiter’s moon, Europa. Uniquely on Earth, plate tectonics is intricately linked to the habitability of our blue planet. Therefore, I embark on a journey to understand plate tectonics from a modeling perspective. First, I will explore melt transport beneath mid-ocean ridge settings, where there are crucial exchanges between the Earth’s interior and the surface. This melt transport has implications for seafloor morphology and the structure and composition of the oceanic lithosphere which forms the bulk of tectonic plates. Then, I will touch upon combining fluid transport with reactive thermodynamics to understand eclogitization of the overlying crust at a subduction zone. Going to one of our nearest planetary bodies, Mars, I use a combination of two-phase flow principles and planetary thermal evolution to model volatile trapping in the early Mars magma ocean to show that there are potentially more volatiles trapped in the Martian interior than previously thought. Water is one of the major components of habitability. To understand the dynamic habitability of Mars, I show how the distribution of water in the various reservoirs can evolve over time. I will end the talk by discussing future work on understanding dynamic habitability on other planetary bodies.
Nov. 6
Dr. Don Fisher
Department of Geosciences
Pennsylvania State University
What Do Observations of Exhumed Tectonic Plate Boundaries Tell Us About Subduction Zone Earthquakes?
Abstract: Field and microstructural observations from exhumed examples of the subduction plate interface are incorporated into a model for the slip behavior of active subduction zones. The observations of natural examples lead to a pressure solution flow law, which is combined with a dislocation creep flow law for quartz-phyllosilicate mixtures and incorporated into a numerical model that depicts interseismic creep, seismicity, and fluid flow, including the fluid flow transients that occur during earthquakes. This model (MEFISTO- a Mineralization, Earthquake, and Fluid flow Integrated SimulatOr) includes:1) an earthquake simulator with temperature-dependent increases in cohesion, 2) a fluid flow model coupled to the earthquake simulator through the link between increasing strength (contact area) and permeability, with both low strength and ambient permeability restored by ruptures of the plate interface, and 3) interseismic creep that responds to variations in stress that could drive acceleration in strain rate toward the later part of the seismic cycle. The fluid moves down a pressure gradient driven by fluid production from metamorphic reactions within and downdip of the seismogenic zone. An increase in average shear stress with increasing lithostatic stress along the interface emerges during simulations, with a very low effective coefficient of friction (~0.07), consistent with the shear stress estimates based on heat flow in the forearc. Pressure solution, which is capable of producing measurable strain in mudstones at the updip end of the seismogenic zone (100-150˚C), increases downdip to a point along the interface where the strain rate is capable of accommodating the plate rate. Model results are used to evaluate how coupled seismic slip and fluid flow relate to earthquake size distributions, aftershocks, precipitation associated with veins, fluid pressure transients, slip deficits during the interseismic period, and fault-restrengthening in the aftermath of earthquakes.
Dec. 4
Dr. Thomas Harter
The University of California, Davis