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2020

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Full-Text Articles in Earth Sciences

Modulation Of Late Pleistocene Enso Strength By The Tropical Pacific Thermocline, Gerald T. Rustic, Pratigya J. Polissar, Ana Christina Ravelo, Sarah M. White Dec 2020

Modulation Of Late Pleistocene Enso Strength By The Tropical Pacific Thermocline, Gerald T. Rustic, Pratigya J. Polissar, Ana Christina Ravelo, Sarah M. White

School of Earth & Environment Faculty Scholarship

The El Niño Southern Oscillation (ENSO) is highly dependent on coupled atmosphere-ocean interactions and feedbacks, suggesting a tight relationship between ENSO strength and background climate conditions. However, the extent to which background climate state determines ENSO behavior remains in question. Here we present reconstructions of total variability and El Niño amplitude from individual foraminifera distributions at discrete time intervals over the past ~285,000 years across varying atmospheric CO2 levels, global ice volume and sea level, and orbital insolation forcing. Our results show a strong correlation between eastern tropical Pacific Ocean mixed-layer thickness and both El Niño amplitude and central Pacific …


African Land Mammal Ages, John Van Couvering, Eric Delson Dec 2020

African Land Mammal Ages, John Van Couvering, Eric Delson

Publications and Research

We define 17 African land mammal ages, or AFLMAs, covering the Cenozoic record of the Afro-arabian continent, the planet’s second largest land mass. While fossiliferous deposits are absent on the eroded plateau of the continent’s interior, almost 800 fossil genera from over 350 locations have now been identified in coastal deposits, karst caves, and in the Neogene rift valleys. Given a well-developed geochronologic framework, together with continuing revision to the fossil record—both stimulated by the story of human evolution in Africa—and also to compensate for the variation in fossil ecosystems across such great distances, the AFLMAs are biochronological units defined …


Meteoritic Evidence For A Ceres-Sized Water-Rich Carbonaceous Chondrite Parent Asteroid, V E. Hamilton, C A. Goodrich, A H. Treiman, Harold Connolly Jr., M E. Zolensky, M H. Shaddad Dec 2020

Meteoritic Evidence For A Ceres-Sized Water-Rich Carbonaceous Chondrite Parent Asteroid, V E. Hamilton, C A. Goodrich, A H. Treiman, Harold Connolly Jr., M E. Zolensky, M H. Shaddad

School of Earth & Environment Faculty Scholarship

Carbonaceous chondrite meteorites record the earliest stages of Solar System geo-logical activities and provide insight into their parent bodies' histories. Some carbonaceous chondrites are volumetrically dominated by hydrated minerals, providing evidence for low temperature and pressure aqueous alteration1. Others are dominated by anhydrous minerals and textures that indicate high temperature metamorphism in the absence of aqueous fluids1. Evidence of hydrous metamorphism at intermediate pressures and temperatures in carbonaceous chondrite parent bodies has been virtually absent. Here we show that an ungrouped, aqueously altered carbonaceous chondrite fragment (numbered 202) from the Almahata Sitta (AhS) meteorite contains an assemblage of minerals, including …


Multiple Constraints Cause Positive And Negative Feedbacks Limiting Grassland Soil Co2 Efflux Under Co2 Enrichment, Philip A. Fay, Dafeng Hui, Robert B. Jackson, Harold P. Collins, Lara G. Reichmann, Michael J. Aspinwall, Virginia L. Jin, Albina R. Khasanova, Robert W. Heckman, H. Wayne Polley Dec 2020

Multiple Constraints Cause Positive And Negative Feedbacks Limiting Grassland Soil Co2 Efflux Under Co2 Enrichment, Philip A. Fay, Dafeng Hui, Robert B. Jackson, Harold P. Collins, Lara G. Reichmann, Michael J. Aspinwall, Virginia L. Jin, Albina R. Khasanova, Robert W. Heckman, H. Wayne Polley

Biology Faculty Research

Understanding ecosystem carbon-cycling responses to atmospheric CO2 enrichment is critical to preserve biodiversity and maintain vital ecosystem services in grasslands impacted by global change. We conducted an 8-y experiment enriching CO2 concentrations from preindustrial to midtwenty-first century levels on grassland plant communities on upland, lowland, and alluvial soils. CO2 enrichment increased the CO2 efflux from soils to atmosphere in amounts depending on whether the dominant limitation was CO2 or feedbacks (net positive or negative) from soil moisture and plant species turnover. These findings highlight how multiple concurrent limitations, not single limitations in sequence, regulate the …


A Conceptual Model Evaluation Framework For Adaptive Governance And Adaptive Management In Large-Scale Restoration Programs, Chadwin Smith Dec 2020

A Conceptual Model Evaluation Framework For Adaptive Governance And Adaptive Management In Large-Scale Restoration Programs, Chadwin Smith

School of Natural Resources: Dissertations, Theses, and Student Research

Adaptive management (AM) has become a kind of plastic phrase applied as a formulaic panacea for most major species recovery and ecosystem restoration efforts now underway across the United States. AM emerged as an application of the scientific method to resource management, closely tying management to science learning through experimental actions. The phrase “learning by doing” best captures the premise behind developing an experimental management approach that could be applied on the larger scale of a river system or ecosystem. In nearly five decades of application, however, examples of successful AM implementation at large scales are few and conflict remains …


3d Numerical Simulation-Based Targeting Of Skarn Type Mineralization Within The Xuancheng-Magushan Orefield, Middle-Lower Yangtze Metallogenic Belt, China, Xunyu Hu, Xiaohui Li, Feng Yuan, Simon M. Jowitt, Alison Ord, Rui Ye, Yue Li, Wenqiang Dai, Xiangling Li Dec 2020

3d Numerical Simulation-Based Targeting Of Skarn Type Mineralization Within The Xuancheng-Magushan Orefield, Middle-Lower Yangtze Metallogenic Belt, China, Xunyu Hu, Xiaohui Li, Feng Yuan, Simon M. Jowitt, Alison Ord, Rui Ye, Yue Li, Wenqiang Dai, Xiangling Li

Geoscience Faculty Research

Recent exploration has identified a series of Cu-Mo skarn deposits within the Xuancheng-Magushan orefield. The orefield forms part of the Nanling-Xuancheng mining district, which is located within the Middle-Lower Yangtze River Metallogenic Belt (MLYRMB) of central-eastern China. However, this area contains thick and widespread unprospective sedimentary cover sequences that have impeded traditional approaches to mineral exploration. This study presents the results of 3D numerical simulation modeling that identifies possible mineral exploration targets within the entire Xuancheng-Magushan orefield. This modeling enables the identification of unexplored areas with significant exploration potential that are covered by thick sedimentary sequences that cannot be easily …


Species Distribution Modeling For Arid Adapted Habitat Specialists In Zion National Park, Sam Driver, Daniel R. Unger, David L. Kulhavy, Chris M. Schalk Dec 2020

Species Distribution Modeling For Arid Adapted Habitat Specialists In Zion National Park, Sam Driver, Daniel R. Unger, David L. Kulhavy, Chris M. Schalk

Student Publications

The Arizona toad (Anaxyrus microscaphus) and Jones’ waxy dogbane (Cycladenia humilis var. jonesii) are habitat specialists with historical ranges in the desert southwest and specifically, Zion National Park (ZION). The machine learning method, MaxEnt, constructed species distribution models (SDMs) in ZION for the two study species at 30 m and 900 m spatial resolutions using climate, topographic, and remotely sensed data. Additionally, 900 m forecasting models were constructed to observe the shifts in suitable habitat for the years 2050 and 2070, based off two representative concentration pathway scenarios. Results indicate promising predictive power for both high …


Coal Energy And Environmental Impacts: Introduction, Luis F. O. Silva, Amy L. Wolfe Dec 2020

Coal Energy And Environmental Impacts: Introduction, Luis F. O. Silva, Amy L. Wolfe

Faculty, Staff, and Affiliated Publications--KGS

No abstract provided.


A Survey On Subsurface Signal Propagation, Usman Raza, Abdul Salam Dec 2020

A Survey On Subsurface Signal Propagation, Usman Raza, Abdul Salam

Faculty Publications

Wireless Underground Communication (WUC) is an emerging field that is being developed continuously. It provides secure mechanism of deploying nodes underground which shields them from any outside temperament or harsh weather conditions. This paper works towards introducing WUC and give a detail overview of WUC. It discusses system architecture of WUC along with the anatomy of the underground sensor motes deployed in WUC systems. It also compares Over-the-Air and Underground and highlights the major differences between the both type of channels. Since, UG communication is an evolving field, this paper also presents the evolution of the field along with the …


Petrology Of The Gradational Intrusive Contact Between The Packsaddle Schist And The Town Mountain Granite, Enchanted Rock State Natural Area, Llano Uplift, Central Texas, Travis Galle Dec 2020

Petrology Of The Gradational Intrusive Contact Between The Packsaddle Schist And The Town Mountain Granite, Enchanted Rock State Natural Area, Llano Uplift, Central Texas, Travis Galle

Student Publications

The Mesoproterozoic intrusive contact between the ~1.1 Ga anorogenic Town

Mountain Granite and the ~1.3 Ga Packsaddle Schist is a gradational contact

exhumed within the Llano uplift. This contact is exposed along the southeastern

margin of the Enchanted Rock batholith in central Texas. Field observations,

hand sample and thin section petrography, and handheld X-ray fluorescence

analysis of hand samples were used to characterize the gradational nature of this

contact at multiple scales. The style of gradation between the Town Mountain

Granite and Packsaddle Schist varies throughout the study area, containing both

injection and permeation. The complex relationships observed at the …


Core Handling, Transportation And Processing For The South Pole Ice Core (Spicecore) Project, Joseph M. Souney, Mark S. Twickler, Murat Aydin, Eric J. Steig, T.J. Fudge, Leah V. Street, Melinda R. Nicewonger, Emma C. Kahle, Jay A. Johnson, Tanner W. Kuhl, Kimberly A. Casey, John M. Fegyveresi, Richard M. Nunn, Geoffrey M. Hargreaves Dec 2020

Core Handling, Transportation And Processing For The South Pole Ice Core (Spicecore) Project, Joseph M. Souney, Mark S. Twickler, Murat Aydin, Eric J. Steig, T.J. Fudge, Leah V. Street, Melinda R. Nicewonger, Emma C. Kahle, Jay A. Johnson, Tanner W. Kuhl, Kimberly A. Casey, John M. Fegyveresi, Richard M. Nunn, Geoffrey M. Hargreaves

Earth Systems Research Center

An intermediate-depth (1751 m) ice core was drilled at the South Pole between 2014 and 2016 using the newly designed US Intermediate Depth Drill. The South Pole ice core is the highest-resolution interior East Antarctic ice core record that extends into the glacial period. The methods used at the South Pole to handle and log the drilled ice, the procedures used to safely retrograde the ice back to the National Science Foundation Ice Core Facility (NSF-ICF), and the methods used to process and sample the ice at the NSF-ICF are described. The South Pole ice core exhibited minimal brittle ice, …


Building An Improved Drought Climatology Using Updated Drought Tools: A New Mexico Food-Energy-Water (Few) Systems Focus, Lindsay E. Johnson, Hatim M.E. Geli, Michael J. Hayes, Kelly Helm Smith Dec 2020

Building An Improved Drought Climatology Using Updated Drought Tools: A New Mexico Food-Energy-Water (Few) Systems Focus, Lindsay E. Johnson, Hatim M.E. Geli, Michael J. Hayes, Kelly Helm Smith

Drought Mitigation Center: Faculty Publications

Drought is a familiar climatic phenomenon in the United States Southwest, with complex human-environment interactions that extend beyond just the physical drought events. Due to continued climate variability and change, droughts are expected to become more frequent and/or severe in the future. Decision-makers are charged with mitigating and adapting to these more extreme conditions and to do that they need to understand the specific impacts drought has on regional and local scales, and how these impacts compare to historical conditions. Tremendous progress in drought monitoring strategies has occurred over the past several decades, with more tools providing greater spatial and …


An Assessment Of The Hydrological Trends Using Synergistic Approaches Of Remote Sensing And Model Evaluations Over Global Arid And Semi-Arid Regions, Wenzhao Li, Hesham El-Askary, Rejoice Thomas, Surya Prakash Tiwari, Karuppasamy Manikandan, Thomas Piechota, Daniele Struppa Dec 2020

An Assessment Of The Hydrological Trends Using Synergistic Approaches Of Remote Sensing And Model Evaluations Over Global Arid And Semi-Arid Regions, Wenzhao Li, Hesham El-Askary, Rejoice Thomas, Surya Prakash Tiwari, Karuppasamy Manikandan, Thomas Piechota, Daniele Struppa

Mathematics, Physics, and Computer Science Faculty Articles and Research

Drylands cover about 40% of the world’s land area and support two billion people, most of them living in developing countries that are at risk due to land degradation. Over the last few decades, there has been warming, with an escalation of drought and rapid population growth. This will further intensify the risk of desertification, which will seriously affect the local ecological environment, food security and people’s lives. The goal of this research is to analyze the hydrological and land cover characteristics and variability over global arid and semi-arid regions over the last decade (2010–2019) using an integrative approach of …


Epithermal Mineralization Of The Bonanza-Sandy Vein System, Masara Gold District, Mindanao, Philippines, Jilian Aira S. Gabo-Ratio, Alfred Elmer Buena, Barbie Ross B. Villaplaza, Betchaida D. Payot, Carla B. Dimalanta, Karlo L. Queaño, Eric A. Andal, Graciano P. Yumul Jr Dec 2020

Epithermal Mineralization Of The Bonanza-Sandy Vein System, Masara Gold District, Mindanao, Philippines, Jilian Aira S. Gabo-Ratio, Alfred Elmer Buena, Barbie Ross B. Villaplaza, Betchaida D. Payot, Carla B. Dimalanta, Karlo L. Queaño, Eric A. Andal, Graciano P. Yumul Jr

Environmental Science Faculty Publications

The Masara Gold District in southeastern Mindanao island is an area of prolific hydrothermal copper and gold mineralization. This study documents the mineralization characteristics of the NW-trending Bonanza-Sandy epithermal veins to constrain possible hydrothermal fluid sources and ore-forming mechanisms. Epithermal mineralization in the NW veins is divided into three main stages: Stage 1 - massive quartz-sulfide; Stage 2 - massive to amorphous quartz-carbonate (calcite); and Stage 3 - colloform-cockade quartz-carbonate (bladed rhodochrosite). Stage 1 is the main gold mineralization phase, with chalcopyrite, pyrite, sphalerite and galena occurring with native gold and tellurides. Stages 2 and 3 contain invisible gold in …


Impacts Of Irrigated Agriculture On The Near Surface And Planetary Boundary Layer Atmosphere: Results From The Great Plains Irrigation Experiment (Grainex), Emilee Lachenmeier Dec 2020

Impacts Of Irrigated Agriculture On The Near Surface And Planetary Boundary Layer Atmosphere: Results From The Great Plains Irrigation Experiment (Grainex), Emilee Lachenmeier

School of Natural Resources: Dissertations, Theses, and Student Research

Modification of natural prairie grasslands into irrigated and rainfed agriculture in the Great Plains produced significant impacts on regional weather and climate including temperatures, precipitation, energy fluxes, and the planetary boundary layer (PBL) atmosphere. The Great Plains Irrigation Experiment (GRAINEX) during the 2018 growing season collected data over irrigated and non-irrigated crop fields to further understand these impacts. The data were collected during two intensive observation periods (IOPs) in early June (IOP 1: 30 May – 13 June of 2018) and late July (IOP 2: 16 July – 30 July of 2018). The data analyzed include latent (LE) and sensible …


Population Demographics, Distribution, And Environmental History Of Asian Carp In A Great Plains River, Jake Werner Dec 2020

Population Demographics, Distribution, And Environmental History Of Asian Carp In A Great Plains River, Jake Werner

School of Natural Resources: Dissertations, Theses, and Student Research

Silver Carp Hypophthalmichthys molitrix, Bighead Carp H. nobilis, and Black Carp Mylopharyngodon piceus, collectively known as Asian carp, are a group of invasive fishes in the U.S.A. that have garnered much attention over the last couple decades. Most research devoted to this group of fishes has been focused in the Mississippi River basin with little investigation in the Missouri River drainage, particularly in tributary systems. The Kansas River is a major tributary to the Missouri River that has multiple anthropogenic barriers creating varying levels of connectivity within the Kansas River itself, and with the Missouri River. Information …


Geochemistry, Petrology, And Palynology Of The Princess No. 3 Coal, Greenup County, Kentucky, Madison M. Hood, Cortland F. Eble, James C. Hower, Shifeng Dai Dec 2020

Geochemistry, Petrology, And Palynology Of The Princess No. 3 Coal, Greenup County, Kentucky, Madison M. Hood, Cortland F. Eble, James C. Hower, Shifeng Dai

Center for Applied Energy Research Faculty and Staff Publications

The high volatile C bituminous-rank, Bolsovian-age Princess No. 3 coal, a correlative of the heavily-mined Hazard No. 7 coal and the Peach Orchard and Coalburg Lower Split coals, was investigated three sites at a mine in Greenup County, Kentucky. The coal exhibits a “dulling upwards” trend, with decreasing vitrinite and a greater tendency towards dull clarain and bone lithotypes towards the top of the coal. The relatively vitrinite-rich basal lithotype is marked by a dominance of lycopod tree spores. The palynology transitions upwards to a middle parting co-dominated by tree fern and small lycopod spores and an upper bench dominated …


Mexican Obsidian On Maui: Hawaiian Connection, Harmonic Convergence, Or Hokum?, Matthew Boulanger Dec 2020

Mexican Obsidian On Maui: Hawaiian Connection, Harmonic Convergence, Or Hokum?, Matthew Boulanger

Anthropology Research

In 2014, the television show America Unearthed (A & E Networks) featured an episode discussing evidence for pre-Columbian contact between Polynesia and continental North and South America. Included in this “evidence” was a large spearpoint, allegedly found on the island of Maui. The show’s host argues that the spearpoint is made on obsidian from central Mexico, and therefore represents evidence for direct contact between Polynesian and Maya peoples prior to the sixteenth century CE. A detailed analysis of the spearpoint, including geochemical sourcing, reveals that it is indeed made of so-called Pachuca obsidian from central Mexico; however, the size, shape, …


Monitoring 2019 Bonnet Carré Spillway Impacts - Final Report, J. Read Hendon, Jerry D. Wiggert, Jill Hendon Dec 2020

Monitoring 2019 Bonnet Carré Spillway Impacts - Final Report, J. Read Hendon, Jerry D. Wiggert, Jill Hendon

Faculty Publications

Due to the multiple and extended openings of the Bonnet Carré Spillway in 2019, the University of Southern Mississippi (USM) was tasked by the Mississippi Department of Marine Resources to conduct ecological sampling in the Mississippi Sound and adjacent waters. in an effort to better understand the impacts of the extensive freshwater diversion of Bonnet Carré Spillway operations on Mississippi's coastal and marine resources. The period of performance for this project was June 1, 2019, to August 31, 2019. This technical report summarizes the three months of weekly surveys and analyses, over June - August 2019, conducted by the University …


Timing Of Deformation Along The Iron Springs Thrust, Southern Sevier Fold-And-Thrust Belt, Utah: Evidence For An Extensive Thrusting Event In The Mid-Cretaceous, J. Daniel Quick, John Patrick Hogan, Michael Wizevich, Jonathan Obrist-Farner, James L. Crowley Dec 2020

Timing Of Deformation Along The Iron Springs Thrust, Southern Sevier Fold-And-Thrust Belt, Utah: Evidence For An Extensive Thrusting Event In The Mid-Cretaceous, J. Daniel Quick, John Patrick Hogan, Michael Wizevich, Jonathan Obrist-Farner, James L. Crowley

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The temporal and spatial distribution of strain associated with the Sevier orogeny in western North America is significantly different in the southern end of the belt, at the latitude of Las Vegas, Nevada, than farther to the north at the latitude of Salt Lake City, Utah. Reasons for these differences have been speculative as a lack of temporal constraints on thrusting in the intervening region hindered along-strike correlation across the belt. We determined a crystallization age of 100.18 ± 0.04 Ma for zircons extracted from a recently recognized dacite lapilli ash-fall tuff near the base of the synorogenic Iron Springs …


Micro-Annulus Generation Under Downhole Conditions: Insights From Three-Dimensional Staged Finite Element Analysis Of Cement Hardening And Wellbore Operations, Weicheng Zhang, Andreas Eckert Dec 2020

Micro-Annulus Generation Under Downhole Conditions: Insights From Three-Dimensional Staged Finite Element Analysis Of Cement Hardening And Wellbore Operations, Weicheng Zhang, Andreas Eckert

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

A micro-annulus (MA) is defined as a high permeability zone or gap initiating/occurring at the casing-cement and cement-formation interfaces during the wellbore life span. An MA can significantly compromise wellbore integrity by establishing enhanced fluid flow pathways. This study uses a staged finite element approach to simulate wellbore integrity during various loading steps of wellbore operations under downhole conditions. Particular emphasis is placed on the processes of cement poro-elastic property evolution, volume variation, and pore pressure variation as part of the cement hardening step. The resulting state of stress during the life cycle of a typical injection well (i.e. hardening, …


Bioconversion Of Industrial Hemp Biomass For Bioethanol Production: A Review, Jikai Zhao, Youjie Xu, Weiqun Wang, Jason Griffin, Kraig Roozeboom, Donghai Wang Dec 2020

Bioconversion Of Industrial Hemp Biomass For Bioethanol Production: A Review, Jikai Zhao, Youjie Xu, Weiqun Wang, Jason Griffin, Kraig Roozeboom, Donghai Wang

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Industrial hemp (Cannabis sativa L.) with robust drought-resistant features has excellent agronomic and pharmaceutical characteristics. As the federal prohibition on hemp cultivation was lifted, its valorization in various aspects is highly required. This review aims to summarize the potential of hemp biomass for bioethanol production. Chemical compositions of hemp biomass were evaluated as compared with those of corn fiber, corn stover, and sorghum bagasse. Several representative pretreatment technologies used for hemp biomass were summarized in terms of sugar recoveries, lignin removal, and sugar and ethanol yields. This review presents numerous technical barriers attributed to insufficient fermentable sugar and ethanol …


Impacts Of Environmental Conditions On Fleas In Black-Tailed Prairie Dog Burrows, Julia E. Poje, Tonie Rocke, Michael D. Samuel Dec 2020

Impacts Of Environmental Conditions On Fleas In Black-Tailed Prairie Dog Burrows, Julia E. Poje, Tonie Rocke, Michael D. Samuel

United States Geological Survey: Staff Publications

Sylvatic plague, caused by the bacterium Yersinia pestis and transmitted by fleas, occurs in prairie dogs of the western United States. Outbreaks can devastate prairie dog communities, often causing nearly 100% mortality. Three competent flea vectors, prairie dog specialists Oropsylla hirsuta and O. tuberculata, and generalist Pulex simulans, are found on prairie dogs and in their burrows. Fleas are affected by climate, which varies across the range of black-tailed prairie dogs (Cynomys ludovicianus), but these effects may be ameliorated somewhat due to the burrowing habits of prairie dogs. Our goal was to assess how temperature and precipitation …


Report On Icdp Deep Dust Workshops: Probing Continental Climate Of The Late Paleozoic Icehouse-Greenhouse Transition And Beyond, Gerilyn S. Soreghan, Laurent Beccaletto, Kathleen C. Benison, Sylvie Borquin, Georg Feulner, Natsuko Hamamura, Michael Hamilton, Nicholas G. Heavens, Linda Hinnov, Adam Huttenlocker, Cindy Looy, Lily Pfeifer, Stephane Pochat, Mehrdad Sarder Abadi, James Zambito Dec 2020

Report On Icdp Deep Dust Workshops: Probing Continental Climate Of The Late Paleozoic Icehouse-Greenhouse Transition And Beyond, Gerilyn S. Soreghan, Laurent Beccaletto, Kathleen C. Benison, Sylvie Borquin, Georg Feulner, Natsuko Hamamura, Michael Hamilton, Nicholas G. Heavens, Linda Hinnov, Adam Huttenlocker, Cindy Looy, Lily Pfeifer, Stephane Pochat, Mehrdad Sarder Abadi, James Zambito

School of Earth & Environment Faculty Scholarship

Chamberlin and Salisbury's assessment of the Permian a century ago captured the essence of the period: it is an interval of extremes yet one sufficiently recent to have affected a biosphere with near-modern complexity. The events of the Permian – the orogenic episodes, massive biospheric turnovers, both icehouse and greenhouse antitheses, and Mars-analog lithofacies – boggle the imagination and present us with great opportunities to explore Earth system behavior. The ICDP-funded workshops dubbed “Deep Dust,” held in Oklahoma (USA) in March 2019 (67 participants from nine countries) and Paris (France) in January 2020 (33 participants from eight countries), focused on …


Interpretation Of Hydrogeologic Data To Support Groundwater Management, Bazile Groundwater Management Area, Northeast Nebraska, 2019—A Case Demonstration Of The Nebraska Geocloud, Christopher M. Hobza, Gregory V. Steele Dec 2020

Interpretation Of Hydrogeologic Data To Support Groundwater Management, Bazile Groundwater Management Area, Northeast Nebraska, 2019—A Case Demonstration Of The Nebraska Geocloud, Christopher M. Hobza, Gregory V. Steele

Publications of the US Geological Survey

Nitrate, age tracer, and continuous groundwater-level data were interpreted in conjunction with airborne electromagnetic (AEM) survey data to understand the movement of nitrate within the Bazile Groundwater Management Area (BGMA) in northeastern Nebraska. Previously published age tracer data and nitrate data indicated vertical stratification of groundwater quality. Younger groundwater sampled within shallow parts of the aquifer had higher concentrations of nitrate, with 70 percent exceeding the U.S. Environmental Protection Agency maximum contaminant level of 10 milligrams per liter. In contrast, groundwater sampled from deeper parts of the aquifer indicated that nitrate concentrations were less than 2 milligrams per liter and …


Estimating The Age And Mechanism Of Boulder Transport Related With Extreme Waves Using Lichenometry, Maria A. Oliveira, Esteve Llop, César Andrade, Cristina Branquinho, Ronald Goble, Sónia Queiroz, Maria C. Freitas, Pedro Pinho Dec 2020

Estimating The Age And Mechanism Of Boulder Transport Related With Extreme Waves Using Lichenometry, Maria A. Oliveira, Esteve Llop, César Andrade, Cristina Branquinho, Ronald Goble, Sónia Queiroz, Maria C. Freitas, Pedro Pinho

Department of Earth and Atmospheric Sciences: Faculty Publications

Tsunamis and storms cause considerable coastal flooding, numerous fatalities, destruction of structures, and erosion. The characterization of energy and frequency associated with each wave contribute to the risk assessment in coastal regions. Coastal boulder deposits represent a physical proof of extreme inundation and allow us to study the effects of marine floods further back in time than instrumental and historical records. Age estimation of these deposits is challenging due to lack of materials (such as sand, shells, corals, or organic matter) that retain information about the passage of time. Lichenometry, a simple age estimation method, which is cost effective, quick …


Thermometry And Microstructural Analysis Imply Protracted Extensional Exhumation Of The Tso Morari Uhp Nappe, Northwestern Himalaya: Implications For Models Of Uhp Exhumation, Sean P. Long, Matthew J. Kohn, Buchanan C. Kerswell, Jesslyn K. Starnes, Kyle P. Larson, Nolan R. Blackford, Emmanuel Soignard Dec 2020

Thermometry And Microstructural Analysis Imply Protracted Extensional Exhumation Of The Tso Morari Uhp Nappe, Northwestern Himalaya: Implications For Models Of Uhp Exhumation, Sean P. Long, Matthew J. Kohn, Buchanan C. Kerswell, Jesslyn K. Starnes, Kyle P. Larson, Nolan R. Blackford, Emmanuel Soignard

Geosciences Faculty Publications and Presentations

Documenting the processes that facilitate exhumation of ultrahigh‐pressure (UHP) rocks at convergent margins is critical for understanding orogen dynamics. Here, we present structural and temperature data from the Himalayan UHP Tso Morari nappe (TMN) and overlying nappes, which we integrate with published pressure‐temperature‐time constraints to refine interpretations for their structural evolution and exhumation history. Our data indicate that the 5.5‐km‐thick TMN is the upper portion of a penetratively deformed ductile slab, which was extruded via distributed, pure shear‐dominated, top‐down‐to‐east shearing. Strain in the TMN is recorded by high‐strength quartz fabrics (density norms between 1.74 and 2.86) and finite strain data …


Structure Analysis Of Natural Wangdaodeite—Linbo3-Type Fetio3, Oliver Tschauner, Chi Ma, Matthew G. Newville, Antonio Lanzirotti Dec 2020

Structure Analysis Of Natural Wangdaodeite—Linbo3-Type Fetio3, Oliver Tschauner, Chi Ma, Matthew G. Newville, Antonio Lanzirotti

Geoscience Faculty Research

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. This paper reports the first structure refinement of natural wangdaodeite, LiNbO3-type FeTiO3 from the Ries impact structure. Wangdaodeite occurs together with recrystallized ilmenite clasts in shock melt veins which have experienced peak shock pressures of between 17 and 22 GPa. Comparison of natural and synthetic wangdaodeite points toward a correlation between the distortion of ferrate-and titanate-polyhedra and the c/a ratio of the unit cell. The Raman spectrum of wangdaodeite is calculated based on the refined structure. Comparison to the reported spectrum of the type-material shows that the Raman peak at 738–740 …


Compost And Biochar To Promote Soil Biological Activities Under Sweet Potatoes Cultivation In A Subtropical Semiarid Region, Josabeth Navarro, Jahdiel Salazar, James Jihoon Kang, Jason Parsons, Chu-Lin Cheng, Alexandria Castillo, Engil Isadora Pujol Pereira Nov 2020

Compost And Biochar To Promote Soil Biological Activities Under Sweet Potatoes Cultivation In A Subtropical Semiarid Region, Josabeth Navarro, Jahdiel Salazar, James Jihoon Kang, Jason Parsons, Chu-Lin Cheng, Alexandria Castillo, Engil Isadora Pujol Pereira

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

South Texas is located in a subtropical semiarid climate, and due to high temperature and irregular precipitation, farmers opt to leave their fields fallow during the summer months jeopardizing overall soil health. We evaluated whether sweet potato (Ipomoea batatas) cultivation coupled with drip irrigation could restore soil biological activities compared with bare fallow. Additionally, because sweet potatoes have high demand of soil nutrients, especially potassium (K), we evaluated the nutrient supply of locally sourced soil amendments. Sweet potato was cultivated during summer 2018 in McAllen, Texas, under control (no fertilizer), NPK (synthetic fertilizer), RC (yard-waste compost), and AC (compost produced …


Characterizing El Niño-Southern Oscillation Effects On The Blue Nile Yield And The Nile River Basin Precipitation Using Empirical Mode Decomposition, Justin A. Le, Hesham El-Askary, Mohamed Allali, Eman Sayed, Hani Sweliem, Thomas C. Piechota, Daniele C. Struppa Nov 2020

Characterizing El Niño-Southern Oscillation Effects On The Blue Nile Yield And The Nile River Basin Precipitation Using Empirical Mode Decomposition, Justin A. Le, Hesham El-Askary, Mohamed Allali, Eman Sayed, Hani Sweliem, Thomas C. Piechota, Daniele C. Struppa

Mathematics, Physics, and Computer Science Faculty Articles and Research

Using new mathematical and data-driven techniques, we propose new indices to measure and predict the strength of different El Niño events and how they affect regions like the Nile River Basin (NRB). Empirical Mode Decomposition (EMD), when applied to Southern Oscillation Index (SOI), yields three Intrinsic Mode Functions (IMF) tracking recognizable and physically significant non-stationary processes. The aim is to characterize underlying signals driving ENSO as reflected in SOI, and show that those signals also meaningfully affect other physical processes with scientific and predictive utility. In the end, signals are identified which have a strong statistical relationship with various physical …