Events

LEO Seminar Series: Liz Catlos and Ginny Catania

The purpose of LEO is to create a more inclusive and educated community within the JSG by sharing and listening to each other’s stories. Speakers will interview each other and talk about why they are involved in Diversity, Equity, and Inclusion efforts and the heart behind their work. By learning more about why individuals are involved in DEI, we will broaden our understanding of the impacts the JSG is making on students, faculty, staff, and greater society. Taking initiative to get to know each other, ask questions, and Listen to Each Other is a skill that will propel us further to be leaders in the geosciences.

DeFord Lecture: Kathleen Johnson

About Dr. Kathleen Johnson (University of California Irvine)

Speleothem researcher that specializes in reconstructing Asian monsoon and California coastal drought dynamics; utilizes instrumental climate data, paleoclimate data and isotope-enabled climate models to investigate the spatial and temporal patterns of natural climate variability, calibrate paleoclimate proxy data and investigate mechanisms of past climate variability.

Member of the Grand Traverse Band of Ottowa and Chippewa Indians and is actively researching with her native community.

DeFord Lecture Series
Since the 1940’s, the DeFord (Technical Sessions) lecture series, initially the official venue for disseminating EPS graduate student research, is a forum for lectures by distinguished visitors and members of our community. This is made possible through a series of endowments.

UTIG Seminar Series: Tapio Schneider, Caltech

Speaker: Tapio Schneider, California Institute of Technology

Host: Yuko Okumura

Title: Clouds and Climate

Abstract: Clouds are an essential regulator of climate. They cool Earth on average by 5 degrees centigrade. Yet despite their importance, the response of clouds to climate change is very uncertain. This is especially true for the low clouds that cover vast areas of tropical oceans. Their primary effect is to cool Earth by reflecting sunlight back to space. I discuss how this cloud cooling may have been very different in past greenhouse climates, and how it may be affected by rising greenhouse gas concentrations, even in the presence of solar geoengineering. To predict our climate future more accurately, breakthroughs in the modeling of clouds and in the accuracy of climate predictions are needed. I will discuss how they may be achieved, thanks to advances in computing and Earth observations from space and our ability to fuse models with massive amounts of data.

Habitability Seminar: Cayman Unterborn, Southwest Research Institute

A seminar from the Center for Planetary Systems Habitability

Speaker: Cayman Unterborn, Research Scientist, Southwest Research Institute

Title: A Matter of Time: The Coupled Role of Stellar Abundances, Exoplanet Radiogenic Heat Budgets and Climatic Evolution

Abstract: A planet’s heat budget is a combination of the retained heat of formation, the energy released due to the gravitational segregation of a Fe core and decay of the long-lived radionuclides U, Th and ⁴⁰K. While secular cooling and the energy of core segregation are dependent on the formation history and magma ocean evolution, the amount of radiogenic heat a planet contains is solely a function of a planet’s total amount of these elements. As refractory elements, U and Th are likely to exist in the same proportions relative to rock building elements in the planet as in the host-star. ⁴⁰K is moderately volatile, and a planet’s abundance is dependent on the degree of processing during planet formation. Recent observations of Solar twins show a range of stellar Th abundances between 60and 250% of the Sun’s (Unterborn et al., 2015), with similar ranges expected for U and bulk K. If this range of radionuclide compositions is indicative of the range of exoplanet radiogenic heat budgets, the thermal and chemical evolution of these planets may be quite different from the Earth.

In this talk I will discuss the results of recent coupled climate and convection models for 1-6 Earth mass stagnant lid planet with probabilistically determined radiogenic heat budgets constrained by observationally-determined abundances of U, Th and K. These models allow us to estimate the rates of surface volcanism, CO₂ degassing from the interior and surface weathering processes. These models allow us to more realistically examine the short-, medium- and long-term climatic effects of varying radionuclide abundance given the different half-lives of the individual elements. An important output of our models is the lifetime of degassing across our parameter space. Using these degassing lifetimes, I will show that the habitable zone planets TRAPPIST-1 f and g are likely too old to be actively degassing today without additional tidal heating as an additional source of heat or the planets undergoing plate tectonics. Additionally, I will present a sample of observed rocky exoplanets both young and massive enough to be likely degassing today, making them prime targets in our search for planets with temperate climates. These results show the importance of estimating the age of a planetary system when assessing its likelihood to harbor Earth-like planets.

https://habitability.utexas.edu/events/

UTIG Discussion Hour: Gail Christeson, UTIG

Speaker: Gail Christeson, Associate Director, UTIG

Title: The AGU Fellow Selection Process: What I Learned From Serving on the Tectonophysics Subcommittee

UT Paleontology Seminar: Dr. Angelina Perrotti

Dr. Angelina Perrotti (Department of Earth, Environmental, and Planetary Science, Brown University and the Department of Geography, University of Wisconsin-Madison)

Diversity in Vegetation and Fire Responses after Pleistocene Megaherbivore Extinction Across the Eastern US.  

DeFord Lecture: Christopher Griffin

Growth, development, and the origin of major vertebrate groups

About Dr. Christopher Griffin (Yale University)

Growth and development of vertebrate animals, using methods from paleontology and developmental biology; Origin of major groups, the influence of growth and development on evolution, and the rapid bursts of change known as evolutionary radiations

DeFord Lecture Series
Since the 1940’s, the DeFord (Technical Sessions) lecture series, initially the official venue for disseminating EPS graduate student research, is a forum for lectures by distinguished visitors and members of our community. This is made possible through a series of endowments.

UTIG Seminar Series: Twila Moon, University of Colorado Boulder

Speaker: Twila Moon, University of Colorado Boulder

Host: Sophie Goliber

Title: Transformed: Observations and implications of rapid reconfiguration of the Greenland Ice Sheet

Abstract: The Greenland Ice Sheet has now lost ice every year since 1998. While broadscale mass loss is well documented, limits in early remote sensing technology restricted the detail with which we could examine local changes on an ice-sheet-wide scale. Areas of slow motion, glacier shear margins, and complex coastal terrain proved especially challenging. Using newly processed satellite-derived ice sheet surface velocities, glacier terminus advance/retreat records, and surface elevation-change data spanning ~1985-2015, we are now able to see ice sheet changes in unprecedented detail. We ask: what is the local character of rapid ice sheet mass loss, and likely implications? We find that widespread glacier terminus retreat is a strong and more consistent climate response indicator than velocity change, but local changes in velocity provide key indicators of rapid ice sheet reconfiguration. Reconfiguration is observed locally as narrowing zones of fast-flow, ice flow rerouting, and likely glacier outlet abandonment. Evidence of these patterns is apparent in all ice sheet sectors. The rapid reconfiguration now well underway in Greenland has wide-ranging implications, including expected changes in subglacial hydrology, solid ice discharge, freshwater flux to the ocean, and transport of nutrients and sediment. Lacking detailed observations of earlier deglaciations and with current limits on ice-sheet model capabilities, the expanding detail of combined observational records may provide a valuable analogue for studying past ice sheet dynamics and for projecting future ice loss.

Cancelled: DeFord Lecture: Frances Rivera-Hernandez

From Grains to Landscapes: Reconstructing Martian Environments at Multiple Scales

About Dr. Frances Rivera-Hernandez (Georgia Tech)

Planetary geologist focusing on using the sedimentary record to reconstruct what the surface of planetary bodies may have looked like in the past and to evaluate whether they had conditions capable of supporting life

DeFord Lecture Series
Since the 1940’s, the DeFord (Technical Sessions) lecture series, initially the official venue for disseminating EPS graduate student research, is a forum for lectures by distinguished visitors and members of our community. This is made possible through a series of endowments.

Special Seminar Online: Elizabeth Wallace, Rice University

Speaker: Elizabeth Wallace, Rice University

Host: Yuko Okumura

Title: Hurricane and climate interactions over the past two millennia: Insights from sediment cores and climate models

Abstract: Atlantic hurricanes threaten growing coastal populations along the U.S. coastline and in the Caribbean islands. Unfortunately, little is known about the forces that alter hurricane activity on multi-decadal to centennial timescales. In this talk, I will use proxy development and proxy- model integration to constrain the spatiotemporal variability in hurricane activity in the Bahama Archipelago over the past millennium. I will present annually resolved archives of storm activity stretching over the past 1000 to 1500 years derived from sediment cores from blue holes on three islands in the Bahama Archipelago: South Andros Island, Long Island, and Middle Caicos Island. I will explore the sensitivity of each site to coarse-grained sediment deposition for modern storms. All three paleorecords capture multi-decadal and longer periods of elevated hurricane activity over the past millennium. Dramatic differences between these records suggest localized controls on the hurricane patterns observed by each island. Compiling the records together more accurately captures regional variations in hurricane strikes. Integrating our new Bahama Archipelago compilation with compiled paleohurricane records from the U.S. coastline indicates a shift over the past millennium from increased storms making landfall along the Gulf Coast to more storms hitting The Bahamas and New England. I attribute these shifting storm patterns to changes in local environmental conditions and/or large-scale shifts in hurricane tracks. Finally, I will address whether variability in hurricane strikes observed in Bahamian paleohurricane records is related to climate or random variability. Using a large suite of synthetic storms run over past millennium climate, I generate 1000 pseudo paleohurricane records containing centennial-scale signal like our proxy reconstructions. However, the signal observed in any individual record of paleohurricane activity from the Bahama Archipelago is driven more by random variability in hurricane tracks than by climate. This work lays the foundation for creating high-resolution paleohurricane records from coastal karst basins and using hurricane models to inform our interpretations of these records.

UT Paleontology Seminar: Matthew A. Brown

Matthew A. Brown (Texas Vertebrate Paleontology Collections, JSG)

Talk topic: The early history of vertebrate paleontology in Texas (1850s-1940).

DeFord Lecture: Davina L. Passeri

Modeling decadal barrier island evolution under future storms and sea level rise

About Dr. Davina L. Passeri (USGS)

Developing integrated models of hydrodynamics and coastal morphology to predict short- and long-term coastal evolution and applying these models to assess coastal vulnerability to drivers such as storms and sea level rise to inform management decision-making

DeFord Lecture Series
Since the 1940’s, the DeFord (Technical Sessions) lecture series, initially the official venue for disseminating EPS graduate student research, is a forum for lectures by distinguished visitors and members of our community. This is made possible through a series of endowments.

Bureau Friday Seminar - Dr. Benjamin Sovacool, University of Sussex

Decarbonisation and its discontents: A critical justice perspective on four low-carbon transitions

What are the types of injustices associated with low-carbon transitions?  Relatedly, in what ways do low-carbon transitions worsen social risks or vulnerabilities?   Lastly, what policies might be deployed to make these transitions more just?  The presentation answers these questions by first elaborating an “energy justice” framework consisting of four distinct dimensions—distributive justice (costs and benefits), procedural justice (due process), cosmopolitan justice (global externalities), and recognition justice (vulnerable groups). It then examines four European low-carbon transitions—nuclear power in France, smart meters in Great Britain, electric vehicles in Norway, and solar energy in Germany—through this critical justice lens. In doing so, it draws from original data collected from 64 semi-structured interviews with expert participants as well as five public focus groups and the monitoring of twelve internet forums.  It documents 120 distinct energy injustices across these four transitions.  It then explores two exceedingly vulnerable groups to European low-carbon transitions, those recycling electronic waste flows in Ghana, and those mining for cobalt in the Democratic Republic of the Congo. The presentation aims to show how when low-carbon transitions unfold, deeper injustices related to equity, distribution, and fairness invariably arise.

UTIG Seminar Online: Evelyn Powell, Harvard University

Speaker: Evelyn Powell, Harvard University

Host: Ginny Catania

Title: Diving Deeper into Antarctic Ice-Mantle Interactions

Abstract: Understanding Antarctica’s past and future ice dynamics critically depends on our ability to accurately model the solid Earth’s response to surface mass loading. This response strongly depends on the assumed mantle rheology, which is highly uncertain for Antarctica—a region of complex 3-D Earth structure and limited observational constraints. Local geodetic observations such as GNSS may provide invaluable constraints on these uncertain parameters. My research demonstrates, however, that traditional modeling insufficiently captures the response of the 3-D viscoelastic mantle. Using state-of-the-art tools (such as high resolution finite volume modeling and adjoint techniques), I show, for example, that incorporating 3-D Earth structure leads to a 30% increase in predicted sea-level rise in the case of West Antarctic collapse. Overall, these methods will lead to more rigorous inversions of mantle structure, and improved hazard predictions for coastal communities. With a better understanding of the dynamics arising due to Antarctica’s mantle structure, we will be better prepared to monitor the stability of Antarctica’s ice sheets in our progressively warming world.