Conference roundup: AGU 2021

Twenty-four members of the Department of Earth and Planetary Sciences presented research at AGU 2021. Posters and recorded talks are available to view through the end of February.

Two dozen members of Washington University's Department of Earth and Planetary Sciences participated in the most recent meeting of the American Geophysical Union (AGU), which took place Dec. 13–17, 2021. Posters and oral session recordings are available to registered attendees through Feb. 28, 2022. Use the fall meeting portal to access daily program highlights and links to recorded content, connect with presenters and other attendees on social media using hashtag #AGU21, and enjoy catching up on all the exciting work coming from EPS!

List of presenters (organized alphabetically)

Walid Ben Mansour, postodoctoral research associate, gave a talk titled "Geodynamics of the Patagonian Slab Window Constrained by Shear Wave Splitting and Seismic Imaging." Ben Mansour showed the results of recent seismic studies in Patagonia with the aim of helping to constrain the geodynamical processes associated with the slab window, and he discussed preliminary results of a body wave tomographic analysis of the same seismic station dataset. Ben Mansour also delivered a talk on "Thermochemical Structure of Gondwana Terranes from Multi-Observable Probabilistic Inversion," in which he applied a joint inversion framework to better constrain models of the post-Gondwana lithospheric mantle evolution.

Paul Byrne, associate professor, gave a talk titled "Some Tesserae on Venus Display Recent and Perhaps Ongoing Deformation." In his talk, Byrne drew attention to several areas on Venus where the narrative of tesserae as ancient can be challenged. Geologically young deformation along tessera margins suggests that a major reassessment of Venus’ geological history and level of current activity is needed.

Emily Culley, graduate student, delivered an oral presentation on "Evaluating the Extent of Highly Pure Anorthosite in Lunar Uplift Structures at Sites of Purest Anorthosite Spectral Identification Using LROC Narrow Angle Camera Photometry." Culley used images from the Lunar Reconnaissance Orbiter Camera (LROC) Narrow Angle Camera (NAC) to determine the extent of soil with very high concentrations of plagioclase in an effort to determine if there is a widespread, thick layer of nearly pure plagioclase within the lunar crust.

Jedidiah Dale, graduate student, delivered a poster on "The Legacy of Valley Entrenchment on the Floodplain and Tributary Basins of the Central Mississippi River." To address uncertainties about the evolution of the Central Mississippi River Valley, Dale extracted longitudinal trends in channel and floodplain morphology, valley relief and bluff draining tributary basin characteristics along the Central Mississippi River Valley from available high-resolution topography. His results have modern implications for sediment delivery to the Mississippi floodplain, and associated hazard and management concerns.

Andrew Flaim, graduate student, presented a poster on "20th Century Atlantic Climate Variability in Water Isotope Proxies from the Iso2k Database." Flaim presented analyses of climate variability across the Atlantic region recorded by water isotope proxies from the PAGES Iso2k database and shared results highlighting the impacts of anthropogenic warming, even in the early- to mid-20th century, which lay a strong foundation for reconstructions of North Atlantic climate that capture decadal to multi-decadal variability.

Hossein Hosseiny, postdoctoral research associate, presented a poster titled "Implementation of Heuristic Search Algorithms in the Calibration of a River Hydraulic Model." Hosseiny demonstrated the utility of heuristic search algorithms in the objective calibration of hydraulic models and described an advance toward the automated prediction of flooding hazards in real-time.

Jack Hutchings, staff scientist, delivered a poster titled "The Journey of a Thousand Good Measurements Begins with One Replicate: Optimizing CRDS Measurements for Capturing Day-to-Day Variations in Triple Oxygen Isotopes of Rainfall." In the poster, Hutchings presented his operating method of a Picarro L2140­-­i CRDS during the analysis of low-latitude rainwaters where confidently resolving daily variations in Δ17O (differences of ~10-20 per meg) is desired, demonstrated the impact of each correction using a rainfall dataset from Uganda, and offered recommendations for other community efforts that aim to measure meteoric Δ17O via CRDS.

Chhavi Jain, postdoctoral fellow, gave an invited talk titled "Probabilistic Geodynamic Modeling as a New Step Towards Interdisciplinary Investigation of the Upper Mantle." In her talk, Jain proposed a novel probabilistic approach to geodynamic modeling based on Bayesian inference that presents a means to combine experimental rock mechanics, theoretical mantle dynamics, and observational geophysics into a self-consistent and statistically-sound framework.

Bradley Jolliff, Scott Rudolph Professor of Earth and Planetary Sciences and director of the McDonnell Center for the Space Sciences, gave a talk titled "Don’t Take the Gruithuisen Domes for Granite!" Jolliff described hypotheses for the origin of the domes and how to test those hypotheses with a landed spacecraft capable of measuring chemical composition, including major elements and incompatible trace elements, and a mid-infrared mineralogic detector that can sense the more highly polymerized silica and K-feldspar minerals.

Bronwen Konecky, assistant professor, presented a highlighted poster on "Storm- to Seasonal-Scale Variations in East African Precipitation δ18O, δ2H, d-excess, and Δ17O from Daily Monitoring in Western Uganda." Konecky used water isotopes to contextualize the moisture source and transport characteristics of intra- to inter-seasonal rainfall in western Uganda, pairing analyses with meteorological as well as land-cover data, and with weather observations from local farmers.

Zongshan Li, graduate student, gave a talk titled "Azimuthal Anisotropy along the Alaska Subduction Zone from Earthquake and Ambient Noise Rayleigh Waves." Li analyzed data from the Alaska Amphibious Community Seismic Experiment (AACSE) and existing nearby seismic stations to determine the azimuthal anisotropy of the crust and upper mantle, which provides insight into oriented structures and deformation.

Claire Masteller, assistant professor, gave an invited talk on "Exploring Patterns in Seismic Attenuation on Rocky Coasts to Assess the Potential for Active Rock Damage Processes and Erosion." In the talk, Masteller presented a promising method for characterizing the response of sea cliffs to wave action, and she discussed the causes and consequences of differences between research sites and the role of rock damage with specific focus on near-shore processes and rocky coast evolution. Masteller also presented a poster titled "Wiggles in Width: Insights Into Alluvial Channel Dynamics From Variability in High-Resolution Downstream Hydraulic Geometry," in which she quantified variations in river channel width and proposed that site-specific deviations can provide insights into alluvial channel dynamics and stability at the reach scale. In addition, Masteller served as the primary convener for oral and poster sessions on "The Role and Relevance of Thresholds and Variability Across Landscapes."

Alessandro Mauceri, graduate student, gave an oral presentation on "New Biomarker Records of Mid-to-late Holocene Hydroclimate and Vegetation Changes in Eastern Amazonia." Mauceri's talk compared biomarker and compound-specific isotopic data with archeological, pollen, geochemical, and charcoal data to evaluate human and climate driven ecological changes recorded in Lago Caranã since the mid-Holocene.

Bill McKinnon, professor, presented a poster titled "A New Global Topographic Map of Enceladus: Geophysical Considerations." McKinnon described a new map of the active ocean world Enceladus produced from Cassini stereo images.

Jordan Neeley, an undergraduate researcher working with Claire Masteller, delivered a poster on "Linking Bedrock River Morphology, Surface Roughness, and Rock Damage in a Blocky River in Southeast Missouri." To explore feedbacks between erosion processes, surface topography, and rock strength, Neeley looked at bedrock channels and block morphology across three sections of the East Fork Black River in southeastern Missouri.

Samuel Patzkowsky, graduate student, presented a poster on "Investigation of the Effect of Episodic Outgassing on Mantle Xenon Isotopes." Patzkowsky developed a numerical model of Xe isotopic evolution in the mantle to explore the effects of discrete, episodic periods of enhanced degassing, regassing, or both. He also showed that the volume of magma generated by the formation of large igneous provinces has the potential to play a significant role on the outgassing of the mantle and the evolution of mantle Xe isotope compositions.

Flora Perlmutter, an undergraduate researcher working with Bronwen Konecky, presented a poster titled "Hydroclimate Response to Volcanic Eruptions in the Common Era from a Globally Distributed, Multi-Archive Network of Water Isotope Proxy Records." Perlmutter investigated the effect of volcanic eruptions on global hydroclimate through the Common Era, using Superposed Epoch Analysis (SEA) of records in the new PAGES Iso2k database, with the aim of developing a better understanding of the response of global hydroclimate to volcanic eruptions, and potentially other sources of aerosol forcing.

Julian Rodriguez, research laboratory assistant, gave a poster on "Development of New High-Precision Noble Gas Methods for the Study of Terrestrial Volatile Origins and Evolution." Rodriguez discussed the Noble Gas Laboratory's ultra-high vacuum system for gas extraction, purification, and separation for noble gas analysis, and reported new high precision measurements that demonstrate the lab's capability to measure heavy noble gas isotope ratios and abundances in a variety of geological samples, including those with very low gas concentrations.

Nadia Sae-Lim, graduate student, gave a talk titled "Investigation of Hydroclimate Shifts around 1000 CE in the High Peruvian Andes." Sae-Lim presented a new 1,800-year plant wax δD record from long-chain n-alkanes along with a suite of geochemical data derived from lacustrine sediments of Lake Chacacocha in southeastern Peru. Her results will help characterize the roles of climate forcings and variability on localized and regional hydroclimate and highland environments of the Peruvian Andes.

Kirsten Siebach, visiting professor, delivered a poster on "Mineral Identification from SToichiometry (MIST) Model with Application to PIXL on Mars 2020 Perseverance." Siebach presented a computational model created to identify minerals in high resolution chemical maps. The model is now being applied to the PIXL instrument on the Mars 2020 rover mission to identify minerals on Mars.

Alian Wang, research professor, presented a poster titled "MIR3000 for Lunar Mineralogy and Volatile Detection." In her poster, Wang described the development of a mid-IR sensor (2.5 - 10 µm), the "MIR3000," for in-situ sensing of silicate mineralogy for lunar surface explorations, targeting NASA's PRISM, CLPS, and ARTEMIS programs.

Michael Wysession, professor, delivered a talk titled "Teaching Advanced Earth and Space Science in High School Physics and Chemistry Courses." In his talk, Wysession presented two new national high school science programs, "Experience Chemistry" and "Experience Physics," that incorporate substantial quantitative Earth and space science (ESS). Wysession also gave an invited talk on "The Legacy of Galileo: Incentivizing Scientific Service," in which he advocated for scientific organizations, governments, and employers to encourage top scientists to use their knowledge and influence help grow public literacy and appreciation of science and to help guide political and professional policy.

Xinmu Zhang, an undergraduate researcher working with Rita Parai, delivered a poster on "The Coupled Evolution of Earth’s Upper Mantle, Continental Crust, and Atmosphere from Noble Gas Isotopes." In the poster, Zhang presented a new model of upper mantle processing, including degassing to the atmosphere, continental crust growth, incorporation of regassed atmospheric noble gases, and radioactive decay of long-lived heat-producing lithophile elements over Earth’s history.

Zhengyang Zhou, graduate student, gave an oral presentation on "Adjoint Seismic Tomography of the Antarctic Continent Incorporating both Earthquake Waveforms and Green's Functions from Ambient Noise Correlation." Zhou presented a method for improving high-resolution images of the crust and upper mantle structure of Antarctica to better understand both the response of the solid earth to ice mass changes and the geological history of the continent.

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