Conference roundup: AGU 2020

Twenty-five members of the Department of Earth and Planetary Sciences presented research at AGU 2020. Posters and recorded talks are available to view through mid-February.

Over 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. 1–17, 2020. Posters and oral session recordings are available to registered attendees through Feb. 15, 2021. 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 #AGU20, and enjoy catching up on the abundance of exciting work coming from EPS!

List of presenters (organized alphabetically)

Ghassan Aleqabi, research scientist, presented a poster on “Sulaimaniyah 2015 Earthquake Swarm Analysis Using Matrix Profile Technique.” In the work presented, Aleqabi uses time series data mining to analyze a large dataset of seismic waveforms to identify large numbers of individual events that comprise a complex earthquake swarm.

Anna Baker, AB '20, delivered a poster on her undergraduate research project titled “Lunar Agglutinate Glass Composition and Implications for Agglutinate Formation.” Baker’s work focuses on the composition of composite particles, agglutinates, that form when micrometeoroids strike the surface of the Moon.

Paul Carpenter, microprobe and XRD facility specialist, gave a talk titled “Chloramphibole in Nakhlite Northwest Africa 13368 and Implications for Halogens on Mars.” Carpenter reported that the chemical composition of the meteorite under study has implications for general mineralogy and Martian igneous petrology. 

John Christian, graduate student, presented a poster on “High Spatial Resolution Thermal Inertia Mapping of Mount Sharp and Northern Plains, Gale Crater, Mars.” The work details the development and implementation of a new approach to retrieving surface thermal inertia values, which provide fine spatial details not observed before, with both scientific and rover mobility applications.

Thomas Condus, graduate student, delivered a poster on “Hematite-Bearing Materials on Mars Identified and Characterized Using MRO CRISM, Opportunity, and Curiosity Data.” In the poster, Condus reported the results of nonlinear modeling of CRISM spectra and Opportunity imaging data for two locations on Mars.

Emily Culley, graduate student, presented a poster titled “Using LROC NAC Photometry to Study the Moon’s Feldspathic Crust.” Culley’s work uses images from the Lunar Reconnaissance Orbiter Camera (LROC) Narrow Angle Cameras (NAC) to investigate compositional characteristics of the lunar surface, particularly the location and extent of rocks with very high concentrations of plagioclase.

Georgina Falster, postdoctoral research associate, gave an invited talk titled “Fingerprinting the Pacific Walker Circulation Using Precipitation δ18O.” Falster used water isotope tracers to reconstruct the Pacific Walker Circulation (PWC), which influences global climate far beyond the Pacific region. She noted that future changes in Earth’s climate will be impacted by both natural and human-driven changes in the PWC, making it critical to understand the PWC’s natural variability over the past millennium as a comparison to future anthropogenic forcing.

Andrea Goltz, graduate student, presented a poster on “Experimental Calibration of an Fe3+/Fe2+-in-Amphibole Oxybarometer and Its Application to Transcrustal Magmatic Processes at Shiveluch Volcano, Kamchatka.” Goltz’s research focuses on determining oxygen fugacity, particularly in primitive arc magmas.

Charis Horn, graduate student, gave an invited talk on “Deformation and Anisotropy of Hydrous Silicates.” To understand the feedbacks between serpentinization, deformation, and seismic anisotropy, Horn analyzed microstructures from a suite of antigorite-bearing samples.

Madison Hughes, graduate student, presented a poster on “Identification and Characterizations of the Basal Sulfate-Bearing Stratum, Northern Mount Sharp, Mars.” The work includes generating a detailed geomorphic map as well as retrieval and characterization of spectra, which are unique for areas traversed and characterized by Curiosity.

Jack Hutchings, staff scientist, gave a talk titled “Phylogenetic, Adaptational, and Environmental Controls on Hydrogen Isotope Apparent Fractionation in Leaf Waxes from a Synthesis of 3,000+ Plant Specimens.” In his talk, Hutchings discussed hydrogen isotopes in plant leaf waxes and how they relate to precipitation and hydroclimate. Based on his examination of more than 3,000 published leaf wax measurements, Hutchings concluded that plant traits, such as lineage and growth form, drive biosynthetic fractionation whereas drier climates lead to enriched leaf water. Hutchings also noted that there are variables still to be accounted for within plant lineages.

Chhavi Jain, postdoctoral fellow, delivered a poster on “Mapping the Subcritical Regimes of Temperature-Dependent Viscosity Convection.” Jain’s research presents the first systematic investigation of subcritical convection in fluids with strongly temperature-dependent viscosity, which may play an important role in the interior dynamics of planetary bodies and icy satellites.

Bradley Jolliff, Scott Rudolph Professor of Earth and Planetary Sciences and director of the McDonnell Center for the Space Sciences, delivered a poster on “Apollo Next Generation Sample Analysis.” With co-authors including assistant professor Kun Wang, research professor emeritus Randy Korotev, and others on the ANGSA science team, Jolliff described previously vacuum-sealed rock samples collected during the Apollo 17 mission and the state-of-the-art analytical methods that will be used to study the new Apollo samples.

Bronwen Konecky, assistant professor, gave a poster on “The Unusual 2018-2019 Rainy Seasons in Western Uganda Through the Lens of Precipitation Isotopes, Satellite Data, and Farmer Observations.” Noting the notorious variability of tropical East Africa’s rainy seasons, Konecky discussed how this rain variability may be an increasing trend contributing to ongoing challenges in food security in the region.

Zongshan Li, graduate student, gave a talk titled “Crust and Uppermost Mantle Structure of the Alaska Subduction Zone from Joint Inversion of Rayleigh Wave Dispersion and Receiver Functions.” Li used newly acquired data to image the crust and uppermost mantle in the Alaska subduction zone, providing a unique look at the structure and hydration of the forearc and incoming plate.

Yuanyuan Liang, graduate student, presented a poster on “Experimentally Testing Whether Magmatic Processes Can Produce Strong Lunar Crustal Magnetism.” Liang’s work tested the hypothesis that subsolidus reduction of ilmenite in or near slowly cooled mafic intrusive bodies could locally enhance magnetic properties in the lunar crust.

Hannah Mark, Fossett postdoctoral fellow, delivered a poster on “Seismic Structure and the Extent of the Slab Window Beneath the Northern and Southern Patagonia Icefields.” Mark presented a new seismic velocity model for Patagonia and noted prominent features and anomalies in the region.

Claire Masteller, assistant professor, gave an invited talk on “Modeling Memory in Gravel Bed Rivers.” Masteller presented a model for riverbed evolution that depends on past flows. According to Masteller’s research, including continuous evolution in mathematical models – giving river system models a memory of past events – produces better agreement with field observations than modeling done with constant assumptions. “We need to be accounting for a dynamic threshold for motion in these systems if we want to improve our predictions of transport and better describe how these systems might evolve or change in response to changing hydrology in the future,” Masteller said.

Bill McKinnon, professor of Earth and planetary sciences, presented “A Kuiper Belt Carol” on the origins of Pluto and Charon. Based on New Horizons encounters with Pluto, Charon, and Arrokoth, McKinnon described the growth of planetesimals and the evolution of the Kuiper Belt. To learn more about McKinnon’s latest work, check out his recent article, “Formation, Composition, and History of the Pluto System: A Post-New-Horizons Synthesis.”

Kaushik Mitra, graduate student, gave a talk on “Manganese Oxide Formation by Oxyhalogens.” Mitra’s results indicate that manganese oxide formation by oxygen is unlikely on Mars, casting doubt on previous conclusions that such oxides are evidence of molecular oxygen on early Mars.

Eleanor Moreland, undergraduate student, presented a poster on “Windblown Basaltic Sands on the Northern Slopes of Mount Sharp and Adjacent Plains, Gale Crater, Mars.” Moreland used a new method to retrieve thermal inertia values and explored relationships between these values, spectral reflectance data, and a distribution of modern sand deposits and bedrock in Gale Crater.

Rita Parai, assistant professor, gave an invited talk titled “Mantle Plume Source Volatile Accretion, Degassing and Regassing,” in which she addresses the driving question, “Was accretion homogeneous?” Parai’s examination of noble gas isotopic signatures allows for tracing and constraining volatile accretion and transport over Earth history, leading to the conclusion that a Xe-poor plume source could reflect heterogeneous accretion.

Nadia Sae-Lim, graduate student, delivered a poster titled “Assessment of 19th and 20th Century Lake and Air Temperature History in the Peruvian High Andes Using Biomarkers and Lake Energy Balance Modeling.” Sae-Lim reconstructed lake surface temperature for the past several centuries using a sediment core from Lake Sibinacocha to investigate the relationship between local lake temperature variability and multidecadal climate oscillations in the Andes.

Tom Stein, computer systems manager, presented a poster on “Science Targets in the Analyst’s Notebook.” Stein described the addition of science targets to the data archives for the Mars Science Laboratory (MSL) and Mars Exploration Rover (MER) missions. View the entire Planetary Data System (PDS) Geosciences Node or browse the analyst’s notebook for the Curiosity, Opportunity, or Spirit rover to learn more.

Zhengyang Zhou, graduate student, delivered a poster on “Radial Anisotropy and Sediment Thickness of West and Central Antarctica Estimated from Rayleigh and Love Wave Velocities.” Zhou’s work contributed to the creation of a new 3D wave velocity model and the first continental-scale sediment thickness map of Antarctica with implications for the geological history of Antarctica.

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