Title: What we did this summer.

Speaker: Diya Kamnani, Ph.D. student with Travis O’Brien.

Title: Dependency of Atmospheric River Frequency on Location, Year and Detection Techniques

Speaker: Kelsey Doiron

Title: Insights into Alkenone Evolutionary History

Speaker: Nicolas Castro-Perdomo, Ph.D. student with Kaj Johnson.

Title: A New Comprehensive Model of Crustal Deformation in the Mediterranean and the Middle East from GNSS Data

Speaker: Owen Madsen, Ph.D. student with Simon Brassell

Title: Assessment of Biogeochemical Potential for Paleoclimactic Reconstruction of the Gray Fossil Site

Title: Exploring Mars for Evidence of Life-Sustaining Environments

Abstract: The climate of Mars has more closely resembled Earth’s climate than that of any other body in our solar system. Orbiting cameras and spectrometers have documented the geographic extent of stream channels, lake beds, and aqueous minerals. The Spirit, Opportunity, and Curiosity rovers documented ancient habitable environments that probably persisted on Mars when microbial life flourished on early Earth. By selecting samples for return to Earth, Perseverance rover is taking the next steps to determine whether life ever existed on Mars.

Title: An integrated earthquake catalogue for Aotearoa New Zealand (version 1) and its implications for earthquake rates

Abstract: A serviceable seismic hazard model requires an earthquake catalogue with accurate event depths, locations, magnitudes, focal mechanisms, and uncertainties. These are especially needed in Aotearoa New Zealand due to its 3D geological and seismological complexity. For the 2022 update to the New Zealand National Seismic Hazard Model, we develop an integrated earthquake catalogue with improved event information. The earthquake data are key inputs into the Seismicity Rate Model component of the 2022 New Zealand National Seismic Hazard Model.

Title: Reservoir Modeling in Tight Rocks using Computational Stratigraphy to Capture Stratigraphic Architecture and Heterogeneity: Examples from the Wolfcamp of the Delaware Basin

Title: Seconds after impact: Insights into impact processes from ultra-high temperature experiments

Abstract: Impact processes are responsible for building and shaping planets and play an important role in the evolution of the chemical and isotopic compositions of Earth and other rocky bodies in the Solar System. This talk presents new insights into impacts processes from ultra-high temperature experiments in an aerodynamic levitation laser furnace. The results of these experiments lead to a better understanding of past impacts on Earth by constraining temperature-time conditions of explosive impact plumes and addressing how impact-induced melt vaporization leads to stable isotope fractionation of impact products.

Title: Teaching and Practicing Geology at a Tribal College: Diné College, Navajo Nation

Abstract: The Navajo Reservation sits on the Colorado Plateau and is home to some of the most iconic landforms with high relevance to geologic sciences. The reservation is located on a portion of Navajo ancestral lands in the Southern Colorado Plateau. Many tribal students have a latent interest in the geology around them and are aware of a plethora of legends involving these iconic rocks. The region also hosts large deposits of coal and uranium. The often-tragic legacy of mining these resources looms large in the minds of many Navajo. My talk is divided into three portions that integrate my students’ interests across teaching and research. Part 1) Teaching Geology: What is working best. Part 2) An investigation into the uranium concentrations in the waters of the Southern Colorado Plateau. Part 3) Ongoing work on the upliftand erosion of the Colorado Plateau using apatite fission track thermochronology.

Title: Studies of Extreme Weather using Machine Learning and Climate Emulators

Abstract: Studying low-likelihood high-impact climate events in a warming world requires massive ensembles of hindcasts to capture their statistics. It is currently not feasible to generate these ensembles using traditional weather or climate models, especially at sufficiently high spatial resolution.

We describe how to bring the power of machine learning (ML) to generate climate hindcasts at four to five orders-of-magnitude lower computational cost than conventional numerical methods. We show how to evaluate ML climate emulators using the same rigorous metrics developed for operational numerical weather prediction.

We conclude by discussing the prospects for studying the causes and statistics of low-likelihood high-impact extremes using huge ensembles generated using these ML emulators.

Title: The Scientific Basis for the Paris Agreement’s 1.5°C/2°C Targets and the Reasons for Urgency

Abstract: The Paris Agreement sets the terms for current international cooperation on climate change. Implementing the Agreement involves several key challenges including that it’s Long-term Objective (stated in Article 2) calls for “Holding the increase in the global average temperature to well below 2°C above pre-industrial levels and pursuing efforts to limit the temperature increase to 1.5°C above pre-industrial levels…” Given previous warming and the difficulty of reducing emissions rapidly, this aspirational goal is almost beyond the reach of plausible policy initiatives. Nevertheless, the risks of exceeding this objective, dubbed by the UN Framework Convention on Climate Change, the progenitor of the Paris Agreement, as “dangerous anthropogenic interference with the climate system” are substantial. In this talk, I explain key aspects of the scientific justification for the 1.5/2°C objective, in context of the political rational for defining such targets at all.

Title: Stratospheric aerosol geoengineering and its impacts on the atmosphere and climate

Abstract: The injection of stratospheric aerosol precursor into the lower stratosphere (SAI) has been proposed to mitigate some of the negative impacts of rising greenhouse gas levels. Despite offsetting global mean surface temperature, various studies demonstrated that SAI could influence the recovery of stratospheric ozone and have important impacts on stratospheric and tropospheric circulation, thereby potentially playing an important role in modulating regional and seasonal climate variability.

Here I discuss some of those impacts of SAI, emphasising that so far most of the assessments of such an approach have come from climate model simulations in which SO₂ is injected only in a single, usually equatorial, region. Using the CESM2-WACCM6 model, a comprehensive Earth System Model with prognostic aerosol microphysics and interactive stratospheric chemistry, and a set of experiments with varying SAI location and/or seasonality, I demonstrate the strong dependence of the simulated stratospheric and tropospheric temperature, circulation and ozone responses on the injection strategy. I also discuss the fine interplay of various radiative, dynamical and chemical processes driving the atmospheric response to SAI.

Title: Spatio-temporal evolution of tectonics and topography in the Pyrenees Mountains

Abstract: The Pyrenees Mountains of France and Spain are an asymmetric, doubly-vergent orogen that formed due to mostly Cenozoic convergence of the European and Iberian plates. The extensive research and exploration efforts on the mountain belt and flanking foreland basins provide an exceptional dataset for investigating feedbacks between tectonics and surface processes. I will present the results of complimentary numerical modeling studies investigating the coevolution of exhumation, deformation, and topographic change in response to the developing orogen. Combined 3D flexural modeling and structural restoration indicate a mountain belt that increased topographic relief rapidly in the late Eocene (~35-30 Ma) followed by slow, limited decay since the Oligocene (~25 Ma). These results provide important constraints for 3D thermo-kinematic modeling; I utilize ~300 low-temperature thermochronology cooling ages to test different models for orogenic exhumation within the previously established topographic framework. The data reveal a westward propagating pattern of exhumation that is primarily controlled by structural inheritance, with ancillary patterns reflecting growth and erosion of the antiformal stack and post-orogenic surface processes. This work underscores the power of combining geologic data with numerical models to test hypotheses, explore driving mechanisms, and understand feedbacks between lithospheric deformation and surface processes.

Title: Identifying the End-Triassic mass extinction event and its impacts on continental ecosystem of the high-latitude Elliot Formation of South Africa

Abstract: The Elliot Formation is one of the few continental rock units that both preserves a rich fossil record and encompasses the end-Triassic extinction (ETE) event, presenting a unique opportunity to investigate how continental extinctions occur and how life recovered from one of the “Big Five” mass extinctions. To fully understand the continental expression of this event on high-latitude ecosystems, we conducted a high-resolution chronostratigraphic assessment at Barkly Pass, South Africa using C-isotope chemostratigraphy and geochronology of detrital zircon. To help characterize ecosystems, we analyzed stable isotopes of tooth/bone phosphate. We found that the ETE there is in upper part of the section and earliest Hettangian to middle Sinemurian. Enamel isotopes suggest aquatic habits for some taxa, providing the first geochemical evidence to support this hypothesis. The lower section preserved a much colder climate of 6.4°C and wetter “taiga” conditions, while the upper preserved a warmer and drier “savanna” environment between 28.5°C and 20.0°C. Given our depositional rate model, climate changed dramatically in a short amount of time (< 1 million years). These data offer clues that will help us understand the rapid expansion of dinosaurs following the ETE.

Title: Fast and Fluvial: The Morphodynamics of Fluvio-Deltaic Systems with High Sediment Concentrations

Speaker: Syan Das, Ph.D. student with Doug Edmonds

Title: Disentangling the relationship between tectonic uplift, channel morphology and sediment grain size.

Speaker: Rubaiat Islam, Ph.D. student with Ginny Gong

Title: The co-occurrence of atmospheric rivers and tropical cyclones significantly increases moisture transport and precipitation intensity

Speaker: Trung Nguyen, Ph.D. student with Ben Kravitz

Title: Staring at the future of extreme precipitation in the Midwest United States