Jan. 30

Dr. Bayani Cardenas

Department of Earth and Planetary Sciences

Jackson School of Geosciences

University of Texas at Austin

Ridge to Reef Volcanic Hydrogeology: Submarine groundwater in the World’s Most Biodiverse Coasts

Abstract: Water flows from land to the ocean not only through rivers and estuaries but also below-ground through coastal and submarine aquifers. While the global fresh submarine groundwater discharge (SGD) is less than 1% of river discharge, it is quite relevant chemically as groundwater nutrient inputs are 25% of riverine inputs. This land-ocean connectivity is important for sensitive ecosystems such as coral reefs if the groundwater delivers solutes that are either critical for or harmful to reef life. Here, we present the interesting but potentially common situation of dramatic SGD in a volcanically active area in the Philippines which has been identified as the world’s most biodiverse coastal area and whose coral reefs provide for local communities.
We studied coastal and submarine thermal springs associated with high fluxes of acidic waters and carbon dioxide, some of which are within or close to thriving coral reefs. The SGD fluxes are amongst the largest in the world and the SGD carbon dioxide fluxes overwhelm coastal carbon budgets. The presentation delivers explanations for the high SGD, discussing the mechanics and different sources and pathways of water, by bringing together multiple lines of evidence from different methods including deep diving, drones, novel sensors, geochemical tracers, thermal remote sensing, and modeling.

Feb. 6

Dr. Peter DeCelles

University of Arizona

Why the Central Andes are Larger than the Himalaya

Abstract: The Central Andean and Himalayan orogenic belts provide an ideal natural experiment to test the potential role of climate in controlling orogeny. Approximately equal in age and along-strike length, both orogenic wedges are forming in plate-marginal convergent tectonic settings: The Andes in a retroarc setting and the Himalaya in a collisional setting against the Tibetan backstop. The Central Andes orogenic wedge is volumetrically and aerially nearly twice as large as the Himalayan orogenic wedge, despite the Himalaya having accommodated at least three times more tectonic shortening. The Himalaya exports at least four times more sediment owing to much greater erosion rates as signified by widespread Cenozoic metamorphic rocks and very young (<10 Ma) low-temperature thermochronologic ages. The Central Andes are thermochronologically old (mostly 20-100 Ma), have no exposures of Cenozoic metamorphic rocks, and are mantled by volcanic and sedimentary rocks, attesting to shallow, slow erosion. The most likely culprit for this situation is the greater intensity of the Indian Monsoon relative to the South American Monsoon since Oligocene time. When viewed as an orogenic wedge that has developed largely after formation of the Tibetan orogenic collage, the Himalaya is neither the largest nor hottest among Earth’s orogens.

Feb. 13

Dr. Yangkang Chen

Bureau of Economic Geology

Jackson School of Geosciences

University of Texas at Austin

AI for Seismology: How to Make it Work for Daily Operation and Better Science

Abstract: Artificial intelligence (AI) has witnessed enormous success in a variety of fields, especially in seismology. It has become widely accepted that deep learning (DL) techniques greatly help routine seismic monitoring by enabling more accurate P- and S-wave arrival picking than traditional methods. However, a completely automatic and in-production AI-driven earthquake monitoring framework has not been reported due to concerns about potential false positives using DL pickers. In this talk, I will introduce a novel AI-facilitated real-time earthquake monitoring framework developed from scratch over the past decade. The choice of optimal DL architecture is based on a decade-long iterative refinement of machine learning models and expansion of the training database. This AI system has been deployed in the Texas seismological network (TexNet) for daily operation. For the West Texas area, the seismic monitoring has been relying on our in-house DL model for reporting earthquakes to the public. For earthquakes with a magnitude above two, the picks are further validated by analysts to output the final TexNet catalog. Due to the fast-increasing seismicity caused by continuing oil & gas production in West Texas, this AI-facilitated framework significantly relieves the workload of TexNet analysts. On the other hand, AI techniques open the door to solving many scientific problems in an unprecedented way, including refining deep earth models with enhanced data preconditioning and iterative solvers, understanding the anthropogenic causes of induced earthquakes, and deciphering the earthquake nucleation mechanisms.

Feb. 20

Dr. Nicola Tisato

Department of Earth and Planetary Sciences

Jackson School of Geosciences

University of Texas at Austin

The Rock-Physics of Geo-Fluids

Abstract: The energy sector has long relied on subsurface exploration, with reservoir fluids playing a fundamental role in ensuring resources. Today, and likely in the future, exploiting the subsurface will be increasingly vital for advancing an energy landscape driven by emerging technologies that address the challenges of the climate crisis, such as geothermal, carbon capture utilization and sequestration (CCUS), and hydrogen storage. Therefore, enhancing our understanding of geologic processes by improving our geophysical toolkit is essential for implementing these innovations and boosting resilience. Here, I present scientific results that offer valuable insights for advancing subsurface imaging, monitoring, and exploration. I will showcase a combination of theoretical work with laboratory and numerical experiments investigating how multiphase fluids – e.g., CO₂ or hydrogen bubble-bearing brines – influence seismic wave propagation in reservoirs. I will also present novel rock physics experiments paired with micro-computed tomography (CT) imaging, revealing how the dissolution and precipitation of minerals in ultramafic rocks control their physical properties during carbon sequestration.

Feb. 27

Dr. Jean Philippe Avouac

California Institute of Technology

Advances in Earthquakes Forecasting

Abstract: Abundant and well documented examples of earthquakes induced by extracting or injecting fluids from the subsurface have provided an opportunity to investigate earthquake physics and test earthquake forecasting models. The presentation will show that spatial and temporal variations of seismicity rate can be predicted well based on stress changes informed by reservoir operations and surface deformation measurements. This modelling framework can be used to mitigate the risk of induced seismicity during CO2 storage of geothermal operations. These progress open avenues for time-dependent probabilistic forecasting of the time, location and magnitude of individual events.

March 6

Dr. Roger Creel

Department of Geology and Geophysics

Texas A&M University

Retreat, Regrowth, and Rapid Thinning: Reconstructing the Holocene History of the Antarctic Ice Sheet

Abstract: Understanding how the Antarctic Ice Sheet changed during past warm periods helps us project how fast Antarctica may shrink during the 21st century. The research I will present constrains Antarctic Ice Sheet change during the Holocene (11.7 – 0 thousand years ago), which is the last time global temperatures may have exceeded early Industrial (1850 CE) values. I will first estimate the Antarctic contribution to Holocene global mean sea level via a statistical framework that merges glacial isostatic adjustment models with observations of past sea level and nearfield Antarctic constraints. This estimate requires constructing the first quantitative estimates of Holocene mountain glacier volume and sea level change due to ocean thermal expansion, which I will discuss. I will then use cosmogenic nuclide exposure ages and marine sedimentary data to reconstruct how Antarctica thinned during the Holocene. I will close by comparing Antarctica’s Holocene history to modern and future trends to give perspective on the response of our largest ice sheet to warming.

March 13

Dr. Marjorie Cantine

University of Washington

March 27

Dr. Manuele Faccenda

Università di Padova

April 3

Dr. Zhe Jia

University of Texas Institute for Geophysics

Jackson School of Geosciences

April 17

Dr. Charlie Kerans

Department of Earth and Planetary Sciences

Jackson School of Geosciences

University of Texas at Austin

April 24

Dr. Karen McKinnon

University of California Los Angeles