Events

DeFord Lecture | Andrew Moodie

Leveraging natural delta land-building processes to enable coastal landscape sustainability by Dr. Andrew Moodie, UT Austin’s Jackson School of Geosciences.

Abstract: River deltas provide many societal benefits, and sustainability of these landforms may be impacted by human modification and global climate change. For example, anthropogenic river control structures inhibit natural sediment dispersal that is necessary to sustain coastal lands in the face of rising sea levels. Declining land area strains human welfare by way of reduced ecosystem services, damaged cultural connections, and hindered economies. To rehabilitate drowning coasts in the Mississippi River delta (Louisiana, USA), engineered river diversions are expected to restore sediment dispersal and promote land growth, but a limited understanding for long-term natural deltaic landscape building processes limits our ability to optimally place diversion structures in space and time. In this presentation, I will demonstrate how reduced-complexity numerical modeling informs natural delta land building processes, supports quantifying societal benefits and costs of diversions, and identifies hazards to land building diversions.

DeFord Lecture Series
Since the 1940’s, the DeFord (Technical Sessions) lecture series, initially the official venue for disseminating DGS 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.

Faculty Retreat

This in an internal event for the Department of Geological Sciences

UTIG Seminar Series: Nathan Bangs, UTIG

Speaker: Nathan Bangs, Senior Research Scientist, University of Texas Institute for Geophysics

Host: Shuoshuo Han

Title: A 3D Look at Subducting Seamounts along the N. Hikurangi Margin, New Zealand, and Implications for Fault Slip

Abstract: Subducting seamounts are thought to contribute to slow slip faulting behavior by introducing significant heterogeneity along the plate interface. However, subducting seamounts are challenging to image once they subduct beneath the accretionary wedge, and their impact on upper plate structure and the plate interface has not been well documented and remains poorly understood. In 2018, an international group of researchers deployed 97 ocean bottom seismometers and acquired a 15 x 60 km2, 3D seismic reflection data volume with the R/V Langseth to image the Northern Hikurangi margin in New Zealand, where both shallow slow slip earthquakes and seamount subduction is active. We have now fully processed these 3D data.

Within the northern side of the 3D volume we discovered a seamount subducted ~4 km subseafloor that is ~ 2 km high and ~ 10 km in diameter and has created distinctive structures within the accretionary wedge. We see landslides on the seafloor consistent with uplift and oversteepening from the passing seamount. Emerging from the top of the seamount we see a low-angle, long offset trailing thrust that enabled the upper plate to propagate onto the seafloor for ~15 km and caused a 1.5 – 2.0 km thick lens of low-velocity, and presumably underconsolidated, overpressured sediments, to follow in the wake of the seamount. Similar structural and physical property patterns within the southern half of the 3D volume, suggests another larger seamount has also passed through this region, but it is now deeply subducted. In this presentation, I will show the structural and hydrogeologic implications of seamount collision and suggest how they may contribute to slow slip.

Faculty Meeting

Internal event for the Department of Geological Sciences

Undergraduate Research Fair

Calling all undergraduates! Interested in getting involved in research at the Jackson School?

Join us for the JSG Undergraduate Research Fair to learn more
Wednesday Sept 7 4:30-5:30 pm
Holland Student Center JGB 2.102
Pizza provided

Faculty Meeting

DeFord Lecture | Marc Hesse

Mass transport through Europa’s ice shell and the habitability of Europa’s internal ocean by Marc Hesse, Department of Geological Sciences at UT Austin

 Abstract: Jupiter’s moon Europa is thought to have an ocean beneath its ice shell and the habitability of this internal ocean may depend on the availability of redox gradients. Downward transport of radiolytic materials produced at the surface through the ice shell likely sets the flux of oxidants into the ocean. Astronomical observations suggest that Europa’s near surface regolith contains 1014 to 1018 mol of O2 and likely other oxidants. Today I will discuss recent work in my group on three different potential transport mechanism for the oxidants through the ice shell: Convective overturn, brine percolation and impacts. Due to the strong temperature dependence of the thermal conductivity the ice-shell has very thick conductive lid that prevents the transport of oxidants through the ice by convective overturn. A second process is the drainage of large volumes of near-surface brines beneath chaos terrains. I argue that these brines percolate readily and can potentially transport surface-oxidants into the ocean at a rate of 106 to 1010 mol/yr. Finally, I discuss the effect of impacts on mass transport through the ice. We have shown that impacts do not need to penetrate the ice shell to generate vertical mass transport. The foundering of impact generated brines though the ice provides a potential mechanism to bring oxidants into the ocean at a rate of 101 to 105 kg/yr. Assuming sufficient production of reductants due to weathering of Europa’s seafloor, our estimated oxidant fluxes are deemed sufficient to sustain primitive life in Europa’s internal ocean. Our simulations also imply that large volumes of near surface brine are not be stable in long timescales, a hypothesis that is testable by NASA’s Europa Clipper mission.

DeFord Lecture Series
Since the 1940’s, the DeFord (Technical Sessions) lecture series, initially the official venue for disseminating DGS 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.

Doctoral Defense | Natalie Wolfenbarger

The final doctoral examination for NATALIE WOLFENBARGER has been scheduled for SEPTEMBER 9, 2022; 10:00AM; ROC 2.201 and VIRTUAL.

The PhD project “Terrestrial Constraints On The Distribution Of Brine In Europa’s Ice Shell” was supervised by Dr. Don Blankenship, Dr. Marc Hesse, and Dr. Krista Soderlund.

Committee members include: William Moore, Timothy A Goudge, and Patrick Heimbach

The defense is open to all members of the University community and the public.

Zoom information:

https://utexas.zoom.us/j/92629021154?pwd=bG5zWXA1NHI1SWdqQ01QamZObmFpUT09
Meeting ID: 926 2902 1154
Passcode: 693276

UTIG Seminar Series: Julia Cisneros, JSG

Speaker: Julia Cisneros, NSF Postdoctoral Fellow, Research Affiliate, The University of Texas at Austin Jackson School of Geosciences

Host: Marcy Davis

Title: The morphology of alluvial sand dunes

Abstract: In the process of sediment transport through a shearing flow, dunes are forming and simultaneously recording their surrounding conditions. These records offer clues about the movement of wind and water across an ancient, otherwise unknown, landscape. In turn, dunes are influencing how sediment is transported. Key to leveraging these records of ancient environments is our understanding of the links between flow, sediment transport, and bedform morphodynamics. To gain that critical understanding, we use modern bedforms to understand the conditions of the Earth and planetary systems and improve how contemporary environments are managed.

This talk will highlight research that aims to investigate dune formation and dune shape in big and small rivers and in shallow laboratory flows. This investigation allows the comparison and validation of the key processes controlling the formation of low-angle dunes. I then identify and discuss the conditions when one process may dominate in creating complex dune shapes. This talk highlights the balance between bedform superimposition and sediment suspension as controls on the formation of low-angle dunes. This information is vital to improving our approach to managing contemporary rivers under modern stressors and revealing the deposits of ancient rivers.

RoKafe

DeFord Lecture | Ashley Matheny

Sensing, synthesizing, and integrating plant ecohydrology for understanding and predicting land-atmosphere feedbacks in response to environmental extremes by Ashley Matheny, Department of Geological Sciences at UT Austin

Abstract: My research explores how forests respond to different stressors across multiple dimensions and scales. This is important because vegetation provides a critical nexus between the subsurface, biosphere, and atmosphere through the mediation of the exchange of water, carbon, and energy. Plants respond dynamically to local microclimates at both short and long time scales via mechanisms ranging from physiological behaviors, such as stomatal closure, to acclimation and adaptation. These responses influence land-atmosphere fluxes directly and are therefore crucial to understanding and predicting Earth system responses to a changing climate. For example, how will ecosystems respond to the coupled extremes of high temperatures and water limitations? By exploring water-use dynamics and photosynthetic rates in trees near the furthest edge of their range limits, we gain insights into how these species will respond to predicted climate shifts in the coming decade. Likewise, through the development of a mechanistic understanding of how trees manifest stress responses, we can better predict the complex feedbacks to carbon, water, and energy fluxes that subsequently develop. In this seminar, I will discuss the work conducted by my team, which is tightly integrated with my graduate and undergraduate education and research programs, to develop novel observational systems and advanced field datasets in conjunction with holistic interpretation methods that facilitate direct data incorporation into multiple model systems leading up to our newest directions and future research.

DeFord Lecture Series
Since the 1940’s, the DeFord (Technical Sessions) lecture series, initially the official venue for disseminating DGS 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.

GeoTalks with Dean Mora

Join Dean Claudia Mora and Executive Director of Academics and Student Affairs Veronica Vasquez for a zoom panel discussion that will highlight the impact of philanthropy on geosciences students.

WHEN: Thursday, September 15 | 9:30am
WHERE:
Via link:
https://utexas.zoom.us/j/99288524072
Via webinar ID:
992 8852 4072

DeFord Lecture | Daniella Rempe

How forests connect the solid earth to its atmosphere by Daniella Rempe, Department of Geological Sciences at UT Austin

Abstract: Earth’s crust is penetrated by plant life. Tree roots commonly extend into bedrock where they exchange water and carbon with the atmosphere leading to mineral transformations. This has consequences for the availability of Earth’s freshwater resources and how these resources evolve over time and space with climate change. In this talk, I describe new insights about how forests interact with underlying bedrock. These insights are gleaned from novel sampling systems, geophysical tools, and remote sensing capabilities that allow us to document how hydrologic and biogeochemical processes in the root-zone manifest at larger scales. I will focus on observations from recent droughts in the western US that motivate a new framework for incorporating bedrock properties into projections of ecosystem and streamflow response to drought.

DeFord Lecture Series
Since the 1940’s, the DeFord (Technical Sessions) lecture series, initially the official venue for disseminating DGS 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: Julia Wellner, University of Houston

Speaker: Julia Wellner, Associate Professor, Department of Earth and Atmospheric Science, University of Houston

Host: Ginny Catania

Title: Sedimentary Record of Ice-Ocean Interactions at Thwaites Glacier, Antarctica: Why all the Fuss about Tipping Points & Doomsday Glaciers?

Abstract: Today, Antarctica is covered by an ice sheet that, if it were to melt, has the capacity to contribute on the order of nearly 60 m to global sea-level rise. Most of that ice is stable, and is expected to be so long into the future, but parts of the West Antarctic Ice Sheet, particularly Thwaites and Pine Island glaciers, are susceptible to sudden retreat. In the geologic past, the ice was significantly expanded, reaching the continental shelf break around most of the margin. As the ice sheet retreated to its modern extent, the shrinking ice left behind a sedimentary signature of deglacial history. Over repeated cycles of glacial advance and retreat, sedimentary deposits of alternating glacial and interglacial periods have built up on the continental shelf. Because the stability of the Antarctic Ice Sheet is strongly influenced by the ocean, the sedimentary deposits from the ice-ocean margin are the ideal place to study the controls on stability or instability of the ice.

This talk will focus on using the sedimentary record from the West Antarctic margin to estimate the controls on glacial stability, examining records of retreat since the last glacial maximum. A focus will be on the sedimentary records from where Thwaites Glacier has retreated over just recent decades, allowing an examination the factors influencing the ice today and how they differ from past periods.

RoKafe

Budget Council Meeting (Faculty)

Internal event for the Department of Geological Sciences (P&T Committee Presentations)

Budget Council Meeting (Faculty)

This is an internal event for the Department of Geological Sciences (P&T meeting)

DeFord Lecture | Liannie Velazquez Santana

Revealing magmatic and tectonic processes through a multifaceted study of the monogenetic volcanic record of the Eastern Bolivian Altiplano by Liannie Velazquez Santana, UT Austin

Abstract: The volcanic products of continental arc volcanoes provide comprehensive insights into the complex nature of magmatic systems. For example, current understanding supports the presence of complex, dynamic transcrustal magmatic systems (TCMSs) that consist of interconnected regions of magma storage where liquid-poor, crystal-rich mushes exist and variably interact. However, the extent to which these petrogenetic pathways affect storage, differentiation, and final eruption (or emplacement) of magmas at different crustal regions within the magmatic system remains challenging to address. In this talk, I will address this through a study of andesitic-dacitic lavas, hornblendite cumulates, and crustal xenoliths from the Pampa Aullagas and Quillacas monogenetic volcanic centers on the Bolivian Altiplano, Central Andes. Through this work, I use a multifaceted analytical approach to 1) characterize the magmatic and crustal components of TCMSs and 2) constrain the tectono-magmatic processes and petrogenetic pathways of magmas at varying timescales and stages within TCMSs.

DeFord Lecture Series
Since the 1940’s, the DeFord (Technical Sessions) lecture series, initially the official venue for disseminating DGS 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.

Hot Science At Home: Successfully Communicating about Climate Change

Is it possible to change an individual’s perceptions about climate change?  Definitely!  Join us for a conversation with Michael Ranney, whose research focuses on understanding and explaining challenging information, including concepts such as global warming and its impacts.  Prof. Ranney shares interventions that have proven to be effective in increasing the acceptance of climate change by people across the political spectrum.

For additional information about our Hot Science events, please visit www.hotsciencecooltalks.org.

UTIG Seminar Series: Juliane Dannberg, University of Florida

Speaker: Juliane Dannberg, Assistant Professor, Department of Geological Sciences, University of Florida

Host: Thorsten Becker

Title: Interactions between Mantle Convection, Plate Tectonics, and Material Recycling in the Earth’s Interior

Abstract: Earth’s interior is largely inaccessible to direct observations, and it remains a fundamental challenge to infer its complex dynamics and to explain how it shapes our planet. I will talk about how we can use computational models of the coupled system of plate motions at the Earth’s surface and convective flow in the Earth’s interior to better understand what drives plate tectonics, how material from the Earth’s surface is recycled through its interior, reaching the surface again as part of massive volcanic eruptions, and what processes control the formation of ocean islands.

RoKafe

DeFord Lecture | David Goldsby

The Rheological Behavior of Ice: From Plasticity to Diffusion Creep by David Goldsby, University of Pennsylvania

Abstract: Knowledge of the rheological behavior of ice over a wide range of stresses is critical for understanding the mechanics and dynamics of glaciers, ice sheets, and icy planetary bodies. In glaciology, the flow behavior of ice has been classically described by the Glen law, a power law relationship between strain rate and stress with a canonical value of the stress exponent of ~3.  We have demonstrated that the Glen law does not describe a single creep mechanism, but rather averages the contributions from two creep mechanisms, dislocation creep at comparatively high stresses and grain boundary sliding creep at lower stresses.  Each of these creep mechanisms dominates the flow behavior of terrestrial and planetary ice bodies at appropriate conditions of temperature, stress and grain size.  At higher and lower stresses than are accessible in most ice deformation apparatus, transitions to plasticity and diffusion creep, respectively, are expected.  Here I will describe our recent experimental efforts to study these deformation mechanisms by 1) mapping out the transition from dislocation creep to power law breakdown and plasticity in a high-pressure gas apparatus, and 2) discovering the diffusion creep regime for ice via cryo-nanoindentation.

DeFord Lecture Series
Since the 1940’s, the DeFord (Technical Sessions) lecture series, initially the official venue for disseminating DGS 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.

40 HOURS FOR THE FORTY ACRES

For 40 hours, Longhorn Nation will come together to support people, places and pursuits across UT. The Jackson School of Geosciences is raising funds to support GeoFORCE, the k-12 outreach program designed to increase the number and diversity of students pursuing STEM degrees and careers, especially in the geosciences.  

Thanks to an anonymous donor, the Jackson School has established a challenge match in which all first-time gifts to support GeoFORCE within the current fiscal year will be matched dollar for dollar. Give today and your gift can double! 

40 HOURS FOR THE FORTY ACRES

For 40 hours, Longhorn Nation will come together to support people, places and pursuits across UT. The Jackson School of Geosciences is raising funds to support GeoFORCE, the k-12 outreach program designed to increase the number and diversity of students pursuing STEM degrees and careers, especially in the geosciences.  

Thanks to an anonymous donor, the Jackson School has established a challenge match in which all first-time gifts to support GeoFORCE within the current fiscal year will be matched dollar for dollar. Give today and your gift can double! 

UTIG Seminar Series: Lorna Kearns, UTIG

Speaker: Lorna Kearns, Postdoctoral Fellow, University of Texas Institute of Geophysics

Host: Chris Lowery

Title: Descent into the icehouse: how overlooked species of planktonic foraminifera maintained community structure through the middle Eocene

Abstract: Humans are changing the Earth. What is unknown is how biotic communities and ecosystems will react to these changes on both short and long timescales. The fossil record can provide us with a means of investigating ecosystem responses to long-term climatic fluctuations which can act as baselines for future anthropogenic induced change. How we utilize the fossil record is therefore of critical importance. The high spatial and temporal resolution of the planktonic foraminifera fossil record provides an ideal system to investigate ecosystem responses to climatic fluctuations at multiple scales and levels. Here I will demonstrate that by using appropriate methods the relationship between planktonic foraminifera and their environment can be used to facilitate a more biologically informed assessment of the fossil record.

I will present a diversity record of planktonic foraminifera through the Middle Eocene Climatic Optimum comprising of 22,800 individuals which shows analytical size fraction choice is a key determinant of diversity signals in deep-time. Furthermore, this record shows that it is small species that maintain ecological function during transient climatic events. Through coupled trait and geochemical analysis, I will then show that survival of one planktic foraminifera genus, Subbotina, through this climatically dynamic interval was aided by trait plasticity and a wider ecological niche than previously thought for a subthermocline dwelling genus supporting a generalist life strategy.

These results raise fundamental questions about how communities respond to climate excursions. In addition, our results emphasize the need to design studies with the aim of collecting the most inclusive data possible to allow detection of community changes and determine which species are likely to dominate future environments.

Philip Bennett retirement celebration

Help us celebrate our incredible retiring faculty!

WHEN: Friday, September 30 | 5:00pm – 7:00pm
WHERE: Holland Family Student Center at the Jackson Geological Sciences Building at 23rd & San Jacinto