Events

UTIG Special Seminar: Will Struble, University of Arizona

Speaker: Will Struble, Postdoctoral Research Associate, University of Arizona

Host: Ethan Conrad

Title: Landslides, Lakes, and Landscapes: Interpreting surface processes and landscape morphology to reveal natural hazards

Abstract: Landscapes evolve through the contribution of uplift and erosion acting over numerous spatial and temporal scales, including by stochastic earthquake and hydrologic processes. Along the Cascadia Subduction Zone, great earthquakes (Mw>8) occur approximately every 300-500 years, but the impact of these earthquakes on the landscape has remained ambiguous. While >20,000 bedrock landslides have been mapped to date in the Oregon Coast Range, no slope failure has been clearly linked with the most recent megathrust earthquake, a Mw ~9.0 that occurred on January 26, 1700. We utilized dendrochronology of drowned ghost forests to determine the age of landslide-dammed lakes in western Oregon, often with seasonal accuracy, and we observed temporal clustering of landslides that records significant regional flooding events. Intriguingly, no dated landslide dams correspond with the 1700 earthquake, emphasizing the outsized role that large storms play in initiating bedrock landslides in the Pacific Northwest. Crucially, the lack of a 1700-dated landslide raises mechanistic questions about processes that may inhibit the triggering of coseismic slope failures, such as the seismic-wave damping properties of old-growth forests.

Over longer timescales, landscape morphology serves as a template that defines where natural hazards occur. For instance, debris flows incise steep valley bottoms and transport significant sediment volumes, especially following wildfire. However, their contributions to setting landscape form, and by extension encoding tectono-climatic processes in the landscape, remain ambiguous. We quantified steepland morphometrics that record debris-flow processes in the San Gabriel Mountains, California. We observed that the drainage area at which steepland, debris-flow dominated valleys transition to fluvial channels correlates with measured uplift and erosion rates. We additionally put forward a landscape evolution model that includes debris-flow incision to reproduce relationships between erosion rate and steepland form and put constraints on the mathematical form of a debris-flow incision law. More broadly, our results allow for enhanced linkages between landscape morphology and processes. Applications include mapping hazards associated with coseismic subsidence during megathrust earthquakes and interpreting drainage network evolution over geologic time.

UTIG Discussion Hour: Sabrina Reichert (UTIG)

DeFord Lecture | Dr. Heather Savage

Earthquake Fever: How Hot do Faults Get? by Dr. Heather Savage, Department of Earth and Planetary Sciences, University of California Santa Cruz

Abstract: During earthquakes, faults heat up due to their frictional resistance. Sometimes, the temperature rise during earthquakes makes the rocks hot enough to melt. However, solidified frictional melt (pseudotachylyte) is not very common in the rock record, and other paleoseismic temperature proxies have only recently been established. The dearth of pseudotachylyte led researchers to hypothesize that faults get very weak during earthquakes, and hence do not produce much heat. However, we have had little information on whether faults produce some amount of heat (enough for faults to weaken during earthquakes but not enough to melt) from the rock record. Here, we use a new sub-solidus temperature proxy, biomarker thermal maturity, to identify temperature rise on faults in a variety of tectonic settings. With this new temperature proxy, we revisit some outstanding questions in fault mechanics such as: Where does earthquake slip occur in a fault zone? Can creeping faults host earthquakes? Does lithology control rupture propagation? and how is energy partitioned during earthquakes? Finally, we have paired these biomarker measurements with K-Ar dating techniques to establish the age of earthquakes on the San Andreas fault at the San Andreas Fault Observatory at Depth (SAFOD).

UTIG Seminar Series: Zhe Jia, Scripps

Speaker: Zhe Jia, Green Postdoctoral Scholar, Scripps Institution of Oceanography

Host: Thorsten Becker

Title: Adventures in unraveling earthquake source complexities and the implications to earthquake physics and hazard mitigation

Abstract: A major challenge in earthquake science is to resolve and comprehend the complexity of earthquake ruptures. These complexities compound earthquakes’ unpredictability and destructive potential. Leveraging advancements in earthquake imaging techniques and multi-geophysical modeling, I show how we quantify earthquake rupture complexities, including recent examples as the 2021 South Sandwich Island earthquake sneaking through subduction interface, the 2019 Ridgecrest, California earthquakes interlocked in continent, and the 2023 Turkey earthquake doublet cascading across a strike-slip plate boundary. These examples show how far earthquakes and their hazards can go beyond our expectation.

I further investigate some key factors controlling these complexities, including fault geometry and pressure/temperature conditions. Using rupture characteristics of numerous small earthquakes, we can now determine high resolution fault geometries without seeing a large event rupture the surface. Additionally, we find temperature and pressure control global large deep earthquake characteristics by gating their mechanism transition from shearing to melting. Explorations on earthquake complexities and controlling factors help bridge theoretical and empirical understanding of earthquakes, and provide insights on the Earth’s multi-scale dynamic processes as well.

DeFord Lecture | Dr. Benoît Cordonnier

Preparing the Next Generation of Rocks Mechanists with 4D-XCT by Dr. Benoît Cordonnier, European Synchrotron Radiation Facility

Abstract: With the new Extreme Brilliant light Source (EBS), the European synchrotron has become the first worldwide 4th generation synchrotron. The 2 orders of magnitude increase in beam brightness has unlocked a new range of possibilities in imaging geosciences, allowing for high resolution in space and time. The constant developments on the beamlines allow multi-resolution scanning from hundreds of microns to submicron observations. The brilliance of ESRF also gives the incredible opportunity to perform in-situ scanning through thick apparatuses in earth-like conditions. Today from long term experiments (project CHRONOS) to high-speed acquisition (project SHOCK/BREAK) we give a flavor of the possibilities ESRF can offer to support Geosciences.

UTIG Special Seminar: Hongyu Sun, Caltech

Speaker: Hongyu Sun, Postdoctoral Scholar in Geophysics, California Institute of Technology

Host: Benjamin Keisling

Title: Next-Generation Seismic Monitoring and Imaging with Artificial Intelligence

Abstract: Numerous natural hazards, such as earthquakes, volcanic activities, and landslides, are sources of seismic waves. Seismology allows us to understand and reduce the risks of these hazards by investigating the origins of the seismic waves and inferring the structure and properties of the Earth’s interior. AI has transformed seismic data analysis, elevating the role of deep learning in seismology. In this talk, I will outline my contributions to improving seismic monitoring and subsurface imaging with AI. I will first present the Phase Neural Operator (PhaseNO) for earthquake detection and seismic phase picking. PhaseNO measures the arrival times of P- and S-waves from continuous seismic data simultaneously across input stations with arbitrary geometries. By leveraging the spatial-temporal information, PhaseNO outperforms single-station AI algorithms by detecting significantly more earthquakes and enhancing measurement accuracy. Additionally, I will show how deep neural networks can overcome the complexities in seismic imaging by being trained to generate seismic waves. These waves, although not directly recorded, are essential for imaging the Earth’s interior. I will provide case studies on full-waveform inversion with active-source seismic data and seismic interferometry with environmental noise. In summary, these AI methods are powerful complements to traditional computational methods and hold significant promise for mitigating natural hazards and climate change.

UTIG Discussion Hour: Michael Shahin (KU)

DeFord Lecture | Dr. Gabrielle Wong-Parodi

The Dynamic Relationship Between Tropical Cyclone Threats and Human Behavior by Dr. Gabrielle Wong-Parodi, Stanford Doerr School of Sustainability, Stanford University

Abstract: Climate change is unpredictable and occurring more rapidly than expected, requiring people act to reduce impacts on the environment and humans. Linear models of behavior change are unsuited for understanding the dynamic relationship between psychological processes (i.e., risk perceptions, emotions) and behaviors (i.e., household preparedness, energy conservation) that unfold against the dynamic and increasing magnitude of climate change-related threats. In this talk, I present longitudinal studies examining this dynamism in the context of tropical cyclones and describe a new model of dynamic climate action. I also discuss the implication of the results for adaptation, and in the design of meaningful interventions to promote protective adaptive behavior.

UTIG Seminar Series: Zhongwen Zhan, Caltech

NOTE: This seminar is hosted jointly with the Bureau of Economic Geology and will be held at 3pm. The seminar will be followed by a reception in the first floor UTIG lobby at 4pm.

Speaker: Zhongwen Zhan, Professor of Geophysics, Seismological Laboratory, Caltech

Host: Duncan Young

Title: Enhancing Environmental Seismology with Fiber Optic Sensing

Abstract: Fiber optic sensing has significantly advanced seismological resolution in recent years, enhancing our ability to study environmental phenomena from tectonic scales down to details as fine as tens of meters. This technological leap offers broad spatial coverage and uninterrupted temporal sampling, addressing challenges in hydrology and glaciology such as deploying and maintaining observational systems with adequate coverage and sensor density. In this lecture, I will discuss two exemplary projects: the South Pole Distributed Acoustic Sensing (DAS) array, utilizing an 8-km fiber-optic cable at the Amundsen–Scott South Pole Station, and the Indian Wells Valley DAS array, operational since 2019. These initiatives underscore the vast research potential at the intersection of fiber-optic seismology, glaciology, and hydrology, showcasing how these technologies can illuminate new paths for environmental seismology.

Hot Science - Cool Talks: "Breaking the Universe"

The powerful James Webb Space Telescope allows us to see back to the beginning of time, shortly after the Big Bang, when the first stars and galaxies were only starting to form. Professor Caitlin Casey will explore with us some exciting new discoveries made using JWST during the first billion years of cosmic time. These discoveries are challenging scientists’ existing understanding about the universe itself and will change the way you see the cosmos.

Planetary Habitability Seminar Series

UT Center for Planetary Systems Habitability Seminar Series. See website for speaker schedule and more details: View Events

Join remotely: https://utexas.zoom.us/j/94052130734

In person: Classroom 15.216B, Physics, Math and Astronomy Bldg.

UT Austin, Department of Astronomy

2515 Speedway, Stop C1400

Austin, Texas 78712-1205

UTIG Special Seminar: Sophie Coulson, University of New Hampshire

Speaker: Sophie Coulson, Assistant Professor, Department of Earth Sciences, University of New Hampshire

Host: David Mohrig

Title: Predicting and Observing Geophysical Patterns of Sea Level Change

Abstract: Rapid melting of ice sheets and glaciers drives a unique geometry, or fingerprint, of sea level change. As an ice sheet loses mass, its gravitational attraction on the nearby ocean is reduced, causing ocean water to migrate away from the ice sheet. Additionally, the solid Earth rebounds in response to the reduction in surface loading. This combination of geophysical processes leads to a sea level fall within ~2000 km of the melting ice sheet and a progressive sea level rise outside of this region. In this talk I will discuss numerical models developed to predict these patterns of sea level change and recent implications for, and conclusion drawn from, observational datasets. Specifically, I’ll explore the fingerprint of sea level change due to ice mass loss from the Greenland Ice Sheet and Arctic glaciers over the last three decades and its effect on sea surface height measurements, GPS data and earthquake hazard.

UTIG Discussion Hour: Okezie Chinemerem (EER & BEG)

DeFord Lecture | Dr. Jerry Mitrovica

New Directions in Modeling of Ice Age Sea Level and Dynamics by Dr. Jerry Mitrovica, Department of Earth and Planetary Sciences, Harvard University

Abstract: Over the last decade there have been major advances in the theory and modeling of ice age sea level changes, including the development of methods that permit high spatial resolution (< 1 km) within global models, improvements in coupling to ice sheet models, and the formulation of adjoint equations that allow for efficient assessments of model sensitivities. I will highlight each advance using case studies focused on problems in paleoclimate, modern climate, and archaeology.

UTIG Seminar Series: Melisa Diaz, The Ohio State University

Speaker: Melisa Diaz, Assistant Professor, The Ohio State University

Host: Benjamin Keisling

Title: Biogeochemistry of a Greenland Ice-Marginal Lake

Abstract: Due to polar amplification, nearly every glacier in Greenland has thinned and/or retreated in recent decades. The meltwater generated from these glaciers can take several paths, ultimately discharging into coastal waters or stored in closed-basin lakes. Ice-marginal lakes are a common but poorly understood feature in many glaciated regions, including Greenland. The lakes receive freshwater input from a combination of subglacial, supraglacial, terrestrial and meteoric sources, and a subset periodically drain, resulting in the rapid discharge of large volumes of water downstream (glacial lake outburst floods – GLOFs). In the case of drainages under adjacent marine terminating glaciers, GLOFs can deposit large amounts of sediment, nutrients, and freshwater directly into coastal waters and fjords. Lake Tininnilik, a large (~40 km2) ice-marginal lake that forms along Saqqarliup Glacier in west Greenland, drains ~2 km3 on quasi-cyclic decadal timescales into Saqqarleq Fjord to the north. For this talk, I will discuss the first comprehensive biogeochemical analysis of Lake Tininnilik and its potential influence on coastal primary productivity, including its major and minor nutrient stoichiometry and microbial composition. As the climate continues to warm, GLOFs are expected to become more frequent in Greenland. Therefore, it is imperative that we understand how these events can impact coastal community resilience.