Earth Sciences Commons^™

Beyond Legacy Indices: A Critical Review Of The Modified Nemerow, Mean Enrichment Quotient, And Aggregated Multivariate Environmental Risk (Amer) Indices For Heavy Metal Pollution In Sediments, Md Shahnul Islam, Anjuman Ara

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Background: Heavy metal pollution in sediments poses persistent ecological risks due to metal toxicity, bioaccumulation, and potential for remobilization. Legacy indices have been widely used for decades but suffer from fundamental flaws, including arbitrary background dependence, lack of grain-size normalization, and poor ecological relevance.

Objective: This review critically evaluates three emerging sediment pollution indices, the Modified Nemerow, Mean Enrichment Quotient (MEQ), and Aggregated Multivariate Environmental Risk (AMER) index, to assess their methodological advances and potential to replace legacy approaches.

Methods: A structured literature search was conducted in Web of Science, Scopus, and Google Scholar (2010–2026). Using an adapted Birch framework, …

A Deep Learning-Based Approach For Mapping Shrubs In Arctic Tundra From Very High-Resolution Imagery, Darko Radakovic, Mark Chopping, Bruce Cook, Aparna S. Varde, Stefan A. Robila

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Arctic shrub expansion is accelerating due to climate warming, but accurately mapping it at fine spatial scales remains challenging due to spectral overlap between shrubs and surrounding vegetation, heterogeneous tundra landscapes, and limited availability of very high-resolution imagery. This study presents a novel mapping and validation approach that integrates very high-resolution (< 1 m) QuickBird (QB) and WorldView (WV) satellite imagery across 12 North Slope sites, using deep learning architectures to map changes in shrub cover from 2002 to 2022. Deep learning models, including Convolutional Neural Network (CNN), ResNet, VGG, U-Net, and Vision Transformer, were trained on 4,100 3-channel pansharpened multispectral images (200×200 m). Two traditional machine learning models (Random Forest and Support Vector Machine) served as a control group. Leave-one-site-out cross-validation showed that all models performed well (AUC-ROC of 0.78–0.86, F1 at validation of 0.33-0.46) and had a moderate to strong agreement with field reference data (R2 = 0.76–0.87). The pretrained VGG and ResNet models achieved the strongest field-reference alignments for shrub cover prediction, while the difference with traditional models was small. Temporal trend analyses for July and August demonstrate a cover change of 0.06–0.45% yr-1 with unweighted mean area slopes and 0.01–0.92% yr-1 inverse-variance weighting. Growth rates were found to depend on the analytical design. Furthermore, the limiting factor in mapping shrub cover was not model complexity but the quality of the training data labels (annotation method explained ∼26% of the error variance). Per-scene cover error was seen across architectures (ρ = 0.67). Comparison with NASA Goddard's LiDAR, Hyperspectral and Thermal (G-LiHT)-derived Canopy Height Models revealed a weak-to-moderate relationship (R2 = 0.04–0.77), suggesting horizontal cover and vertical canopy structure capture complementary aspects of shrub abundance. These results demonstrate the potential of deep learning to map decadal shrub expansion at sub-meter resolution.

Predictive Modeling Of Heavy Metal Pollution And Ecological Risk For Sustainable Water Quality Management In The Ny–Nj Harbor System, Md Shahnul Islam, Sara Naveed, Huan Feng, Tapos Kumar Chakraborty

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Evaluating and forecasting surface water quality is essential for protecting aquatic ecosystems and improving water resource management. This study introduces a novel paradigm that integrates machine learning (ML) with the potential ecological risk index (PERI) to dynamically forecast, rather than statically assess, ecological risks from heavy metal contamination in an urban estuarine environment. Surface water samples from the Lower Passaic River in New Jersey, USA, were analyzed for copper (Cu), lead (Pb), and mercury (Hg) across multiple sites and sampling campaigns. Concentrations ranged from 3.1 to 42.6 µg/L for Cu, 1.8 to 25.4 µg/L for Pb, and 0.12 …

Construct Overlap Inflates Apparent Economic-Capacity Alignment: Evidence From A Hebei City Panel, 2014–2023, Shuo Pang, Jianguang Hou, Danlin Yu

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Index-based urban sustainability studies often ask whether urban resilience and economic development evolve harmoniously, but the answer is unreliable when the two constructs contain the same economic indicators. A targeted audit of recent Chinese coupling studies shows that economic variables are commonly embedded in urban-resilience systems without a reported construct-overlap weight check. Using Hebei, China, as a measurement-validity test rather than as another provincial economic-growth case, this study analyzes a balanced 2014–2023 panel of 11 prefecture-level cities. Duplicated economic concepts account for 44.4% of the baseline resilience-index entropy weight and 88.2% of the baseline economic-index weight, indicating substantial mechanical exposure …

Compound Multi-Hazard Assessment Under Cmip6 Climate Scenarios: Tracking Seasonal Flood-Landslide And Drought-Fire Interactions Across Nepal, Kripa Shrestha, Karthik Reddy Duddukunta, Pankaj Lal, Md Mehedi Hasan, Md Mahfuzur Rahman, Neera Shrestha Pradhan

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Climate-induced hazards in mountain systems rarely occur in isolation, instead they interact through cascading and compounding pathways that single-hazard assessments fail to capture. In Nepal, extreme monsoon rainfall can trigger landslides that dam rivers and generate secondary flooding, while prolonged dry spells create drought, desiccate vegetation fuels, and elevate fire risk. Yet, most regional studies map hazards independently, providing limited insight into how compound zones emerge under climate change. We therefore, develop a seasonal multi-hazard framework that model drought, forest fire, flood, and landslide susceptibility for historical baseline (1991-2020) and future (2021-2100). Three machine learning algorithms (Explainable Boosting Machine, Random …

Measurement Discipline For Sustainable Industrial Transition: Frontier Productivity Evidence From Shandong And Jiangsu Manufacturing, 2013-2023, Shaopu Wu, Jianguang Hou, Danlin Yu

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Sustainable industrial transition requires productivity evidence that separates real efficiency improvement from scale expansion, capital deepening, and reporting change. This study develops a reproducible frontier-productivity diagnostic for provincial leading industry policy, using official 2013-2023 sector panels for 23 two-digit manufacturing sectors in Shandong Province and a matched 2019-2023 benchmark against Jiangsu. The framework combines input-oriented Banker-Charnes-Cooper (BCC) data envelopment analysis (DEA), Simar-Wilson bootstrap bias correction, Malmquist total factor productivity change (TFPCH) decomposition, producer price index (PPI) deflation diagnostics, scale-productivity classification, and targeted sensitivity tests. Bootstrap correction lowers mean BCC efficiency from 0.77 to 0.69 in Shandong and from 0.79 to …

Mapping Public Engagement With Environmental Finance In The U.S: Spatiotemporal Insights From Google Trends On Public Engagement And Policy Equity In The U.S, Hilda Afeku-Amenyo, Charles Knoble, Pankaj Lal

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

This study analyzes U.S. public engagement with environmental finance from 2015–2023 using Google Trends data for four key terms: “green bonds,” “sustainable finance,” “climate finance,” and “ESG.” Our analysis reveals a notable rise in engagement with environmental finance topics, with Environmental, Social, and Governance (ESG) investing generating the highest levels of interest. Geographically, the District of Columbia exhibited disproportionate search activity relative to other regions. While public awareness of environmental finance has grown, we highlight disparities in knowledge and accessibility of information. These findings carry significant policy implications, particularly in ensuring equitable access to sustainable financial instruments. We underscore the …

Decomposition In Urban Forest Patches Across A New York-New Jersey Urbanization Gradient, Cailee Sprouse

Theses, Dissertations and Culminating Projects

"Urbanization causes habitat fragmentation, pollution, homogenization of soil profiles, and replacement of native flora and fauna, which can alter vital ecological processes like decomposition. It is essential to investigate the impacts urbanization may have on ecosystem functioning to better inform urban land management. Studies have shown conflicting results on the impacts of urbanization on soil decomposition rates, with some showing higher, lower, or similar decomposition rates in urban soils compared to rural soils. This study aims to investigate the effects of urbanization and soil characteristics on decomposition rates in three urban forest patches in New Jersey and New York using …

Mineralogy, Geology, And Geochemistry Of The Mcafee Quarries And Greater Mcafee Area, Sussex County, New Jersey, Cristian J. Van Rossen

Theses, Dissertations and Culminating Projects

The Franklin Marble is one of North America’s most famous geologic units, a result of its complex geology, diverse mineralogy, and significant ore deposits. While it has been widely studied, a location that has received little attention is that of the quarries at McAfee, Vernon Township, NJ. This study addresses this oversight by investigating the mineralogy, geology, and geochemistry of the marble and associated geologic units found in the area. Sample analysis consisted of physical and optical analysis as well as chemical analysis using SEM-EDS. Geochemical analysis using ICP-MS allowed for major, trace, and rare earth element concentrations of select …

Signatures Of Vapor Evolution In Turbulent Convection Cells Recorded By K And Rb Isotopes In Chicxulub Impact Spherules, Courtney Jean Rundhaug, Martin Schiller, Martin Bizzarro, Zhengbin Deng, Hermann Dario Bermúdez

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The Cretaceous–Paleogene boundary (∼66 Ma) records the Chicxulub asteroid impact, a pivotal event in Earth's history that affected much of the Earth's surface. While products of this impact have been widely studied, the thermodynamics of the plume and formation mechanisms of certain impact materials remain unclear. This study investigates conditions within the intermediate fraction of the Chicxulub impact plume (pyrocloud) using K and Rb isotope signatures of Gorgonilla Island impact spherules with published δ25Mg data to trace evaporation and condensation processes during ejecta dispersion. The δ41K and δ87Rb signatures vary from −1.18 ± 0.04‰ to 0.43 ± 0.09‰ and − …

Engineering Ferrate(Vi) For Water And Wastewater Treatment: Translating Science Into Technology, Zepei Tang, Zhenli He, Yang Deng

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Over the past five decades, ferrate(VI) (FeO42–) for water and wastewater treatment has remained largely at the laboratory scale, with limited pilot- and full-scale implementation. This gap between sustained research and scarce real-world deployment places the technology in the Valley of Death─a high-risk stage of development─and highlights the need for an engineering-centric approach to enable practical application. This article presents an engineering framework to guide the development and translation of ferrate(VI) technology for water and wastewater treatment. From a system perspective, ferrate(VI) technology comprises three core subsystems: generation, treatment, and solid–liquid separation. Technology maturity depends on both the advancement of …

Trade Liberalization Under Safta And Bimstec: Evidence From A Cge-Gtap Case Study Of A Small Open Economy, Gita Bhushal, Pankaj Lal

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Regional trade liberalization via preferential agreements increasingly shapes economic outcomes in small open economies embedded in overlapping regional frameworks. This study evaluates the short-run economy-wide effects of tariff and non-tariff measure (NTM) reforms under the South Asian Free Trade Area (SAFTA) and the Bay of Bengal Initiative for Multi-Sectoral Technical and Economic Cooperation (BIMSTEC) using a Computable General Equilibrium (CGE) model calibrated to the GTAP 10 database. Gravity-based estimates of ad valorem equivalents (AVEs) of NTMs are integrated into the CGE framework, enabling explicit modeling of regulatory barriers alongside tariff reductions. Policy simulations examine scenarios involving a 90 percent tariff …

Scenario-Based Economic Valuation Of Forest Carbon Sequestration In Nepal: Implications For Redd+ (2030–2050), Gita Bhushal, Pankaj Lal

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Land use and land cover (LULC) change strongly influences national carbon dynamics and the effectiveness of forest-based climate mitigation strategies, particularly in mountainous developing countries. This study integrates scenario-based LULC modeling, spatially explicit carbon accounting, and economic valuation to assess how alternative development pathways affect carbon storage and its economic value in Nepal over the 2020–2050 period. LULC projections for four scenarios: Business-as-Usual (BAU), Rapid Urban Development (RUD), Forest Degradation and Terai Contraction (FDTC), and Agricultural Land Abandonment and Ecological Recovery (ALER), were generated using the TerrSet Land Change Modeler, with 2020 as the baseline. These projections were then used …

Forest Aboveground Biomass In The Southwestern U.S. From Misr And Gedi: Assessment With Nasa Carbon Monitoring System Data, Mark J. Chopping, Zhousen Wang, Crystal B. Schaaf, Michael Bull

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Forest aboveground biomass (AGB) density mapping initiatives generally use one of three remote sensing approaches: lidar, radar, or near-nadir multispectral imaging leveraging machine learning methods, or a combination thereof. However, the active instrument record is limited and near-nadir multispectral imaging data are relatively insensitive to canopy physical structure. Multiangle imaging enables annual wall-to-wall mapping with a global record that extends back to 2000 as these data are highly sensitive to forest AGB. This paper describes work to validate estimates in a published annual, wall-to-wall record of forest AGB on a 250 m grid, derived using 672 nm imagery from the …

Application Of Organic Geochemistry To The Characterization Of Hydrochar And Biochar: Insights Into Composition And Optimization, Michael A. Kruge, Teresa A. Centeno, Alvaro Amado-Fierro, José Manuel González-Lafuente, Rubén Forján, José Luis Gallego

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Hydrothermal carbonization has garnered significant attention in recent studies due to potential applications of the hydrochar produced, which overlap with those of torrefied biochar, including soil improvement, carbon sequestration, and energy production. However, unlike the relatively uniform properties of biochar, hydrochar characteristics can vary greatly depending on the feedstock used. Advanced characterization techniques are essential to better understand these materials and enhance their practical applications. Research on hydrochar requires a multi-faceted approach, including molecular-level studies, to optimize production processes and identify specific applications.

In this regard, analytical methods commonly used in organic geochemistry could play a crucial role in deepening …

An Integrated Approach To Groundwater Management In Northern New Jersey Watersheds, Toritseju Oyen

Theses, Dissertations and Culminating Projects

Groundwater deterioration has emerged as a pressing global concern, with widespread observations of declining water quality in various regions. The predominant cause of this deterioration is attributed to anthropogenic activities, which are deeply intertwined with daily human practices that contaminate water resources. Over the decades, many forested and wetland areas have been converted mainly for increased urbanization and industrialization use in northern New Jersey. The region’s watershed, already characterized as a low-yield aquifer, is facing deterioration because of continuous change in land cover. Anthropogenic activities aimed at providing solutions to problems, such as food scarcity, icy roads during the winter …

Linking Shoreline Change, Environmental Forcings, And Sedimentological Resilience In Nourished Beaches Of Cape May And Wildwood, New Jersey, Usa: A Multi-Decadal Synthesis, Divomi Balasuriya, Greg Pope

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Beach nourishment is a widely used strategy to mitigate coastal erosion, yet its long-term geological impacts remain poorly understood. This study provides a multi-decadal synthesis of shoreline change and sedimentological evolution on the nourished beaches of Cape May and Wildwood, New Jersey, USA. Using shoreline positions from 1991 to 2024, we identify contrasting trajectories: Wildwood exhibits ‘persistent transition’ with severe northern erosion (EPR: −10.0 m/yr) feeding southwards accretion, while Cape May demonstrates a ‘managed equilibrium’ with widespread accretion (mean EPR: +1.15 m/yr). Wave energy correlations account for less than 15% of shoreline variability, indicating natural drivers have been superseded by …

Microbial Metabolism Amplified Warming In Three Phanerozoic Hyperthermal Events, Yuyang Wu, Haijun Song, Daoliang Chu, Ying Cui, Jacopo Dal Corso, Genming Luo, Huyue Song, Li Tian, Hanchen Song, Enhao Jia, Jinnan Tong

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The ocean’s biological carbon pump (BCP) plays a crucial role in climate regulation by facilitating long-term removal of atmospheric CO2. However, BCP changes during past hyperthermals remain poorly understood. Here we use the vertical carbon isotope (δ13C) gradients between surface and mid-waters to trace the BCP changes during the Permian−Triassic, early Toarcian, and Palaeocene−Eocene hyperthermals, detecting a two- to three-fold increase in the vertical δ13C gradients. We found that enhanced organic matter remineralization, driven by increased microbial respiration under warming, are the primary trigger for increased vertical δ13C gradients. Warming-induced enhancements in microbial metabolism caused a two- to six-fold reduction …

Onset Of Strong Iceland-Scotland Overflow Water 3.6 Million Years Ago, Matthias Sinnesael, Boris Theofanis Karatsolis, Paul N. Pearson, Anne Briais, Sidney R. Hemming, Leah J. Levay, Tom Dunkley Jones, Ying Cui, Anita Di Chiara, Justin P. Dodd, Deepa Dwyer, Deborah E. Eason, Sarah A. Friedman, Emma Hanson, Katharina Hochmuth, Halima E. Ibrahim, Claire E. Jasper, Saran Lee-Takeda, Danielle E. Leblanc, Melody R. Lindsay, David D. Mcnamara, Sevasti E. Modestou, Margaret A. Morris, Bramley J. Murton, Suzanne Oconnell, Gabriel Pasquet, Sheng Ping Qian, Yair Rosenthal, Sara Satolli, Takuma Suzuki, Thena Thulasi, Bridget S. Wade

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

North Atlantic Deep Water (NADW), the return flow component of the Atlantic Meridional Overturning Circulation (AMOC), is a major inter-hemispheric ocean water mass with strong climate effects but the evolution of its source components on million-year timescales is poorly known. Today, two major NADW components that flow southward over volcanic ridges to the east and west of Iceland are associated with distinct contourite drift systems that are forming off the coast of Greenland and on the eastern flank of the Reykjanes (mid-Atlantic) Ridge. Here we provide direct records of the early history of this drift sedimentation based on cores collected …

Environmental Justice In Indigenous Communities: The Disproportionate Effects Of Environmental Contamination, Rae Cade, Danlin Yu, Charles Knoble, Kyle Whyte, Pankaj Lal, Cortni Borgerson

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Indigenous communities in New Jersey, New York, and Pennsylvania (referred to as the northeastern United States) face disproportionate environmental pollution, with mortality rates 60 % higher than their white counterparts –an inequity that extends beyond formal recognition categories. While previous research has revealed pollution from facilities that cause severe health issues in Indigenous communities, broad geographic studies examining the spatial correlation between Environmental Justice (EJ) indicators and Indigenous populations remain limited. This study addresses this gap by examining contamination patterns across the northeastern United States, focusing on Superfund sites, drinking water violations, oil spills, and natural gas releases. Our analysis …

A Hedonic Analysis Of Combined Sewer Overflows (Csos) In Northern New Jersey, Taylor Wieczerak, Pankaj Lal, Pralhad Burli, Benjamin Barnett Witherell, Erik Lyttek, Bernabas T. Wolde, Ava Distaso

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Significant water pollution caused by flooding due to heavy precipitation and extreme weather events has become a considerable problem, and changing weather patterns and sea level rise attributable to global climate change stand to further exacerbate the issue. During heavy precipitation events, combined stormwater and untreated sewage may be diverted to adjacent water bodies via combined sewer overflows (CSOs), resulting in contamination and water pollution that can be harmful to human and environmental health. Though water quality effects of CSO discharges have been studied, the socio-economic aspects of this infrastructure have not received much scientific attention. This study provides an …

Millennial-Timescale Thermogenic Co2 Release Preceding The Paleocene-Eocene Thermal Maximum, Shijun Jiang, Ying Cui, Yasu Wang, Maurizia De Palma, B. David A. Naafs, Jingxin Jiang, Xiumian Hu, Huaichun Wu, Runjian Chu, Yangguang Gu, Jiuyuan Wang, Yizhou Huang, Miquela Ingalls, Timothy J. Bralower, Shiling Yang, James C. Zachos, Andy Ridgwell

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Geologic records support a short-lived carbon release, known as the pre-onset excursion (POE), shortly before the Paleocene-Eocene Thermal Maximum (PETM; ~ 56 Ma). However, the source and pace of the POE carbon release and its relationship to the PETM remain unresolved. Here we show a high-temporal-resolution stratigraphic record spanning the POE and PETM from the eastern Tethys Ocean that documents the evolution of surface ocean carbon cycle, redox and eutrophication, confirming the global nature of the POE. Biomarkers extracted from the sedimentary record indicate a smaller environmental perturbation during the POE than that during the PETM in the eastern Tethys …

Magnesium, Iron, And Calcium Isotope Signatures Of Chicxulub Impact Spherules: Isotopic Fingerprint Of The Projectile And Plume Thermodynamics, Courtney Jean Rundhaug, Martin Schiller, Martin Bizzarro, Zhengbin Deng, Hermann D. Bermúdez

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The Cretaceous-Paleogene boundary (KPB) represents a massive extinction event in Earth's history, probably triggered by the Chicxulub asteroid impact ∼66 Ma. The event dispersed vast volumes of ejecta materials including exceptionally preserved impact spherules in the Gorgonilla Island KPB section. Previous work identified three populations of spherules at Gorgonilla: 1) ballistically transported molten spherules, 2) a mixture of molten and condensed spherules dispersed by the expansion of a high-temperature, turbulent cloud (the "pyrocloud"), and 3) tiny droplets condensed from the plume (the "fireball layer"). We determine the Mg, Fe, and Ca isotopic compositions of pristine spherules to better understand the …

Source Apportionment And Potential Health Risks Of Trace Metals In A Contaminated Urban River In New York/New Jersey Harbor System, Md Shahnul Islam, Sana Mirza, Huan Feng, Tapos Kumar Chakraborty, Yu Qian, Shinjae Yoo

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The Lower Passaic River (LPR), located within the New York/New Jersey Harbor Estuarine System, has experienced long-term industrial activities, resulting in elevated concentrations of trace metals in sediment and water. This study aims to assess the bioaccumulation behavior, potential human health risks, and sources of copper (Cu), lead (Pb), and mercury (Hg) in the LPR. Trace metal concentrations were measured in water, sediment, and seven edible aquatic species. Data were analyzed using statistical approaches, and evaluated by bioaccumulation factors (BAFs) and human health risk assessments based on U.S. Environmental Protection Agency (USEPA) guidelines. Results showed that Hg exhibited the highest …

Exploiting Chloride Conservative Tendencies As Contaminant Surrogates In Groundwater Transport Modeling In A Typical Hydrogeological Environment Of Northern New Jersey, Toritseju Oyen, Duke Ophori

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

This study investigates the transport of chloride, a conservative tracer and surrogate for contaminants, in the fractured Brunswick aquifer of northern New Jersey using a dual-porosity MODFLOW-MT3DMS model. Focusing on the First Watchung Mountain region—a microcosm of northern New Jersey’s hydrogeological environment encompassing Montclair State University and adjoining communities, the numerical model simulates groundwater flow and solute transport in a hydrogeologically complex, urbanized setting. Results indicate that chloride migrates through the fractured aquifer via both local flow systems (e.g., Third River) and regional flow systems (Passaic River) within decades. Chloride concentrations exceeded the EPA’s 250 mg/L threshold much faster in …

Extremely Poleward Shift Of Antarctic Circumpolar Current By Eccentricity During The Last Interglacial, Lijuan Lu, Xufeng Zheng, Michael E. Weber, Victoria Peck, Brendan T. Reilly, Zhong Chen, Wen Yan, Tianyu Chen, Hong Yan, Xun Gong, Shuzhuang Wu, Liwei Zheng, Shiming Wan, Yan Du, Lisa Tauxe, Qinghua Yang, Stefanie Brachfeld, Trevor Williams, Yasmina M. Martos, Zhiheng Du, Marga García, Lara F. Pérez, Hu Yang, Bingyue Huang, Jonathan Warnock, Shuh-Ji Kao

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

The Antarctic Circumpolar Current (ACC) exerts substantial control on the physical, chemical, and biological properties of the Southern Ocean, playing a key role in modulating the global carbon cycle and climate. However, the orbital-scale forcing and future changes in the strength and position of the ACC remain elusive. Here, we reconstruct the history of ACC extending back to the Last Interglacial (LIG; 128-113 ka) using sediment cores from the Scotia Sea. Based on high-resolution measurements of sortable silt mean grain size, we find that bottom current speed is synchronized with eccentricity, superimposed by precession. During the LIG when both eccentricity …

Lead Exposure In The 21st Century: Modeling A Path From Crisis To Prevention, Danlin Yu

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

No abstract provided.

Does Bubble Nucleation Occur Heterogeneously In Magmas Feeding Explosive Rhyolite Eruptions? Insights From The Rock Magnetic Properties Of Pumice, Kelly N. Mccartney, Julia E. Hammer, Thomas Shea, Stefanie Brachfeld, Thomas Giacheetti, Bruce F. Houghton

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Nanometer-scale titanomagnetite crystals have been detected in nominally aphyric rhyolite pumice, but whether they are numerous enough to impact bubble nucleation in explosive silicic volcanism was unresolved. This study examines sub-micron crystals using rock magnetic techniques, Rhyolite-MELTS modeling, and physical characterization. We analyzed pumice from four eruptions spanning wide ranges in intensity, storage depth, and bubble number density (1016 to 1013 m−3 liquid): 1060 CE Glass Mountain, 1912 CE Novarupta, 232 CE Taupo, and 0.45 Ma Pudahuel. Calculations assuming monospecific assemblages of 10 and 1,000 nm cubic particles yield titanomagnetite number densities of 1021 to 1013 m−3 dense rock equivalent, …

From Coastal Retreat To Seaward Growth: Emergent Behaviors From Paired Community Beach Nourishment Choices, Jorge Lorenzo-Trueba, Arye Janoff, Oshane Thomas, Di Jin, Porter Hoagland, Andrew Ashton

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Coastal communities often address shoreline erosion through beach nourishment, adding externally sourced sand to widen beaches for recreation and property protection. While nourishment enhances beachfront property values, the need for periodic maintenance creates interdependencies where the actions of neighboring communities affect local shoreline dynamics. Using a coupled model of two neighboring communities, we examine the interplay between community nourishment decisions and the redistribution of nourishment sand. We find that the value a community places on wider beaches not only influences their propensity to nourish, but also their and their neighbors' nourishment efficiency and net benefits. Communities that nourish more frequently …

Activation Or Deactivation? Rethinking Ferrate(Vi) Reactivity Within A Broader Modulation Framework, Zepei Tang, Yang Deng

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

No abstract provided.