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U-Pb Calcite Geochronology, Epr, Geochemistry, And C-O-Sr Isotopes Of Africanomarbles In The Seferihisar (İzmir, Türkiye) U-Pb Calcite Geochronology, Epr, Geochemistry, And C-O-Sr Isotopes Of Africano Marbles In The Seferihisar (İzmir, Türkiye), Fatma Şi̇şman Tükel, Namik Aysal, İpek Deni̇z Yildirim, Marcel Guillong, Tonguç Uysal, Si̇nan Öngen, Emre Erdem

Turkish Journal of Earth Sciences

The Africano marbles (Africano Verde and Bigio Africano) extracted from the region of Sığacık (ancient Teos) region and its surroundings were widely used and even traded in construction and decorative items throughout the Roman period due to their brecciated and colourful appearance. There are two different types of Africano marble, the first consisting of marble breccias embedded in a dark matrix. In this type, the marble breccias show micritic, microsparitic, and sometimes sparitic textures formed by coarse-grained calcite, while the dark matrix consists of chlorite and/or serpentine minerals. The second type is Bigio Africano, which consists of grey-blue homogeneous limestones, …

Remotely Sensed High-Resolution Soil Moisture And Evapotranspiration: Bridging The Gap Between Science And Society, Jingyi Huang, Vinit Sehgal, Laura V. Alvarez, Luca Brocca, Shuohao Cai, Rui Cheng, Xinghua Cheng, Jinyang Du, Bassil El Masri, K. Arthur Endsley, Yilin Fang, Jie Hu, Mahesh Jampani, Md Golam Kibria, Gerbrand Koren, Lingcheng Li, Laibao Liu, Jiafu Mao, Hernan A. Moreno, Angela Rigden, Mingjie Shi, Xiaoying Shi, Yaoping Wang, Xi Zhang, Joshua B. Fisher

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

This paper reviews the current state of high-resolution remotely sensed soil moisture (SM) and evapotranspiration (ET) products and modeling, and the coupling relationship between SM and ET. SM downscaling approaches for satellite passive microwave products leverage advances in artificial intelligence and high-resolution remote sensing using visible, near-infrared, thermal-infrared, and synthetic aperture radar sensors. Remotely sensed ET continues to advance in spatiotemporal resolutions from MODIS to ECOSTRESS to Hydrosat and beyond. These advances enable a new understanding of bio-geo-physical controls and coupled feedback mechanisms between SM and ET reflecting the land cover and land use at field scale (3–30 m, daily). …

Recent U.S. Government Policy Literature On Critical And Strategic Minerals, Bert Chapman

Libraries Faculty and Staff Scholarship and Research

Critical and strategic minerals have become increasingly important in U.S. government civilian and military policymaking in recent years. This is demonstrated by the heavy use of such minerals in many critical civilian and military infrastructures. This work will discuss how this subject has been addressed in laws, presidential documents, and works by government agencies along with congressional oversight committees and support agencies. It will stress how the United States is heavily dependent on strategic minerals from adversarial foreign countries such as China and will examine U.S. efforts to increase its ability to produce such materials in the United States by …

Leveraging Machine Learning Models For Enhanced Landslide Prediction In Western North Carolina, Andrew Edmonds

Graduate Theses and Dissertations

Landslides pose significant hazards to human safety, infrastructure, and the environment, particularly in regions of high elevation that experience extended periods of heavy rainfall. This research focuses on preparing and evaluating landslide susceptibility maps (LSMs) for the Blue Ridge Mountains, a portion of the Appalachian Mountains in western North Carolina, utilizing three machine learning algorithms: Logistic Regression, Random Forest, and Gradient Boosting Regression. Sixteen landslide conditioning factors, reflecting topographic, geological, environmental, and anthropogenic influences, were identified for model input. The landslide inventory database, comprising 7,350 locations, was randomly divided into training (80%) and testing (20%) sets. The performance of each …

Ediacaran Paleocommunity Structure, Body Size Evolution, And The Rise Of Complex Animals, Matthew Philip Craffey

Dissertations and Doctoral Documents, University of Nebraska-Lincoln, 2023–

The Ediacaran period (635-538ma) is a key interval in the evolution of life as it records the first macroscopic animal communities. Major extinction pulses appear to have altered the composition of the global marine biosphere between each sub-interval of the Ediacaran Period: the Avalon, White Sea, and Nama assemblage Zones. While considerable attention has been paid to the causes of these extinction pulses, less has been afforded to the consequences of Ediacaran biotic turnover for community organization and function. Moreover, it is unclear how body size - the defining trait of macrofauna - affected the transition between animal groups across …

Assessing Spatial And Temporal Variation In Photoprotective Responses Of Deciduous And Evergreen Tree Canopies With Leaf Spectroscopy, Alexander Piper

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

Environmental conditions frequently prevent carbon fixation by plants, leading to the absorption of excess light that can damage photosynthetic machinery if not dissipated. To do so, plants utilize several photoprotective mechanisms, some detectable remotely using Photochemical Reflectance Index (PRI). Two components of PRI correspond to the facultative engagement of the xanthophyll cycle (ΔPRI) and constitutive changes in xanthophyll pigment pool sizes (PRI0), representing distinct mechanisms regulating shorter and longer-term photoprotection, respectively. Our understanding of interspecific and intraspecific variation in these mechanisms is limited, primarily because PRI components are often not clearly distinguished. This study aimed to assess the variation in …

Radar Precursors To Severe Weather Reports In Left-Moving Supercells, Eric A. Carothers

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

While much research has examined dual-polarimetric signatures of right-moving supercells, very little has been done with left-moving supercells. Given that left-moving supercells are thought to be disproportionate producers of large hail, understanding their internal dynamics is vitally important. This study examines differences and trends in the dual-polarimetric signatures of left-moving supercells to identify precursors to severe weather reports. A dataset of left-moving supercells associated with severe weather reports was created. These storms are processed with an automated analysis algorithm that identifies and quantifies the polarimetric signatures in each storm. A method for analysis of differences and trends in their dual-polarization …

Sediment And Debris Flows Resulting From The 2020 El Dorado Wildfire, San Bernardino Mountains, California, Andrew Suarez

Electronic Theses, Projects, and Dissertations

The Yucaipa Ridge is a section of the San Bernardino Mountains within the Transverse Ranges of Southern California. During the summer and early fall of 2020, Yucaipa Ridge experienced severe vegetation damage from both the Apple and El Dorado wildfires. Burned slopes exhibit a higher susceptibility to geomorphic change within several years of burning from the introduction of meteoric water onto the slope. Yucaipa, Oak Glen, and other nearby communities are currently at risk of damage by hyperconcentrated flows and debris flows during the seasonal rainy season.

Debris flows and hyperconcentrated flows (a.k.a. mudflows; are grouped and referred to in …

Post-Fire Debris Flow Initiation Potential Based On Forensic Analysis Of Debris Flow Occurrence From The 2020 El Dorado Wildfire On Yucaipa Ridge, San Bernardino County California, Seth Clemen D. Saludez

Electronic Theses, Projects, and Dissertations

This study focuses on the potential debris flow initiation and effect in areas affected by the El Dorado Fire in the Southern San Bernardino Mountains. It uses novel technology combining drone-based photography and LiDAR imaging to create surface models of areas where potential debris flows could initiate, flow, and be deposited. The scans were repeated as geomorphic change occurred through the wet season to document spatial and volumetric changes resulted from the flows. These measurements were combined with traditional fire assessment and observational methods to characterize pertinent conditions.

As we investigated potential debris flow risk in this study area, we …

Integrated Coastal Science And Dune Management: A South Carolina Perspective, Michelle Harris

Theses and Dissertations

Historically, coastal dunes have been poorly understood from a societal perspective despite their protective role in attenuating incoming waves to reduce onshore flood risk. As developed coastlines promote strategies to design and maintain managed dune systems, it is necessary to ensure these strategies are optimized for dune health and resilience, particularly given the increasing threat of natural and anthropogenic stressors. This dissertation work aims to identify strategies that influence coastal dune management in South Carolina (SC), USA from an integrated approach, including a current use assessment, a mesoscale field-based study on strategy efficacy, and by incorporating a societal assessment and …

Quantifying The Rates Of Coastal Change Along Smith Island, Maryland, Sarah Lacy, Ravi Sankar

Longwood Senior Thesis Proposal

As increased climate variability continues to alter the environment, coastal landscapes are becoming increasingly vulnerable to geomorphic change. Coastal erosion, driven by rising sea levels, land subsidence, more intense storm events and human-induced activities poses a serious threat to the sustainability and resilience of island environments like Smith Island, a small marsh island located in the Chesapeake Bay. This study investigates the impacts of recent shoreline change along selected alongshore segments of the island’s coast. Using a combination of aerial imagery, field surveying techniques, and novel geospatial analyses, the project aims to identify areas at highest risk of erosion and …

The Formation Of Glacier Dirt Cones, Ryan M. Strickland, Matthew D. Covington

Geosciences Faculty Publications and Presentations

Glacier dirt cones are meter-scale cones of ice covered with sediment and rock. The cones develop through a process known as differential melt, whereby ice underlying thick debris melts more slowly than bare ice. We report observations of dirt cones on the Kuskulana Glacier, Alaska and develop a model that simulates the growth of dirt cones from debris-filled pits in the ice. With this model, we vary ice melt rates, hillslope debris diffusion rates and pit geometry. Cone heights scale with the square root of debris volume and growth occurs in three distinct stages: emergence, flux-controlled growth and melt-controlled growth. …

A Comprehensive Assessment Approach For Multiscale Regional Economic Development: Fusion Modeling Of Nighttime Lights And Openstreetmap Data, Zhe Wang, Jianghua Zheng, Chuqiao Han, Binbin Lu, Danlin Yu, Juan Yang, Linzhi Han

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Assessing regional economic development is key for advancing towards the Sustainable Development Goals and ensuring sustainable societal progress. Traditional evaluation methods focus on basic economic metrics like population and capital, which may not fully reflect the complexities of economic activities. Nighttime light (NTL) has been validated as an alternative indicator for regional economic development, yet limitations persist in its evaluation. This study integrates OpenStreetMap (OSM) data and NTL data, providing a novel data integration approach for evaluating economic development. The study uses mainland of China as a case, applying ordinary least squares (OLS) and geographically weighted regression (GWR) to evaluate …

Geochronology Of Senèze, Eric Delson, Sébastien Nomade, Sevket Sen, Evelyne Debard, Jean-François Pastre, Jean-Jacques Bahain, Qingfeng Shao, Christophe Falguères

Publications and Research

The age of the Senèze mammalian fauna has been discussed since it was first reported in 1892. 40Ar/39Ar ages reported by Nomade et al. (2014) and recalculated here to agree with current standards placed the deposits between 2.20 and 2.07 Ma. Paleomagnetic data collected in 2001 and 2004 help to narrow the age range, especially of the levels yielding fossils in 2001–2006. In the western sector, fossils can be securely dated between 2.10 and 2.08 Ma, while in the southeastern sector, they are slightly older, between 2.20 and 2.18 Ma. Senèze is one of the few later Cenozoic European sites …

College Of Natural Sciences Newsletter, Spring 2025, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Page 1 Dean's Message from Dr. Sen Subramanian
Page 2 Student Spotlights
Page 3 Kaushik honored, Three-Minute Thesis, & Ice Cores revealed
Page 4 Alumni Spotlight
Page 5 Day of Scholars
Page 6 Cyanide research, Record Research Expenditures, Adhikari awarded Miller Research Award
Page 8 Hanson Receives NSF Grant
Page 9 Snow Lab Research Team
Page 10 Faculty Awards
Page 11 Drone Day
Page 13 Khalaf Awarded Presidential Award

The Compass - Volume 94 Issue 2 - Complete Issue, Scott R. Beason

The Compass: Earth Science Journal of Sigma Gamma Epsilon

No abstract provided.

Efficiency Of Labor In Winter Pruning Of Apple Trees Using Technological Innovations, Élio Fillipi Dos Santos, Wendel Paulo Silvestre, Lessandra Silva Rodrigues, Carine Cocco

School of Earth, Environmental, & Marine Sciences Faculty Publications

The increase of new technologies in fruit-growing crops has increased productivity in cultural practices and helped farmers expand their production areas. This work aimed to quantify labor performance in winter pruning of apple trees, using manual and electronic scissors associated with utilizing a pruning platform and ladders. The treatments consisted of two types of pruning shears and two support systems. A pruner carried out pruning for 16 days, with a journey of 10 h per day. The average yield in manual pruning with a ladder was 21.35 plants pruned per hour per man. Using a platform, the yield increased to …

College Of Natural Sciences 2024 Year-End Publication, College Of Natural Sciences

College of Natural Sciences Newsletters and Reports

Page 2 Dean's Message
Page 3 Department Highlights
Page 4 One Day for State
Page 5 New Students in Wecota
Page 6-8 Faculty Excellence
Page 9 SDSU Physics Students Recognized
Page 9 Prairie Doc Watch Party
Page 10-11 Student Excellence
Page 11 Connections Abroad
Page 12-13 CNS’s Research Centers
Page 14 Connections Abroad
Page 14 Dean Wolf-Hall Retired
Page 15 Outreach Program
Page 15 Events and Traditions
Page 16 Student Spotlight
Page 17 Alumni Spotlight
Page 18-19 SDSU Alum at Paris Paralympics
Page 20 Work Anniversaries & Programs

Impact Of Carbonate-Hosted Zn-Pb Ore Deposits On Groundwater Chemistry: Üzümcü-Olgunlar Mining Site (Hakkari, Türkiye), Ci̇han Tuncer, Yüksel Örgün Tutay, Muhterem Demiruğlu

Turkish Journal of Earth Sciences

Hakkari, known for its high economic value Zn-Pb deposits in Türkiye, has been predominantly producing Zn ore for about 20 years. This study investigated the hydrogeochemical properties of groundwater and surface water collected from the vicinity of carbonate-oxide Zn-Pb mine sites in southern Hakkari to evaluate the effects of mineral deposits and mining activities on groundwater chemistry, as there are potential sources of natural pollution. Samples were collected four times at regular intervals during 2021–2022 from points determined upstream, downstream, and around the mine sites, springs, and streams. The samples were analyzed for majorions, trace elements, and isotopes (18O, 2H, …

Characterizing Rainfall Variability Within A Series Of Storms Over Northern California In February 2017, Parker Jan Malek

Dissertations and Theses

In February 2017, a series of storms with associated atmospheric rivers (ARs) made landfall in the US state of California, dropping large amounts of precipitation over the Sierra Nevada Mountains and their western foothills. The rainfall from these ARs, long, narrow bands of water vapor that transport large amounts of water vapor from the tropics to the mid-latitudes, instigated the near-failure of the Oroville Dam located at the southeastern edge of the Feather watershed outside the city of Oroville in the state's Central Valley. This case study provides a synoptic and mesoscale diagnosis of the drivers of rainfall pulses that …

Earth Orbital Rhythms Links Timing Of Deccan Trap Volcanism Phases And Global Climate Change, Thomas Westerhold, Edoardo Dallanave, Donald Penman, Blair Schoene, Ursula Röhl, Nikolaus Gussone, Junichiro Kuroda

Geosciences Faculty Publications

At the end of the Cretaceous, the massive Deccan trap (DT) volcanic eruptions are regarded as the primary driver of global climate deterioration. Accurate age models are key to unravel the sequence of events related to DT volcanism onset and effects on the global climate system. We establish a direct geochemical link between DT volcanism as recorded in marine osmium isotopic data and global climate change documented in benthic foraminifera carbon and oxygen isotope records. Based on our state-of-the-art astronomically calibrated age model, two major shifts in marine ¹⁸⁷Os/¹⁸⁸Os at 66.49 and 66.28 million years ago are …

Alfred Russel Wallace Notes 35. Natural Selection By Evolution., Charles H. Smith

Faculty/Staff Personal Papers

Alfred Russel Wallace (1823?1913) is remembered, with Charles Darwin, as the co-originator of the concept of evolution by natural selection. But Wallace’s framing of the idea increasingly became one in which natural selection itself was regarded as a law of nature, not a theory per se.

Accurate Estimation Of Jujube Leaf Chlorophyll Content Using Optimized Spectral Indices And Machine Learning Methods Integrating Geospatial Information, Nigela Tuerxun, Sulei Naibi, Jianghua Zheng, Renjun Wang, Lei Wang, Binbin Lu, Danlin Yu

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Leaf chlorophyll content (LCC) is vital for photosynthesis and ecosystem functioning; it influences carbon, water, and energy exchanges while serving as an indicator of photosynthetic activity and nitrogen levels in precision agriculture. Hyperspectral data enable precise LCC monitoring by extracting spectral indices through optimal band combination (OBC) and predicting LCC with machine learning. However, OBC faces dimensionality issues, and machine learning models often overlook geographical influences, potentially reducing prediction accuracy. This study hypothesizes that developing spectral indices from important wavelengths and integrating geospatial data into machine learning models can address these issues and increase prediction accuracy. To test this hypothesis, …

Deformation Characteristics And Influential Factors Of The Surface Uplift Of Closed Mines, Luo Jin, Li Yingming, Guo Qingbiao, Zhao Guangming

Coal Geology & Exploration

Objective The residual surface deformations of closed mines exhibit prolonged duration and complex evolutionary processes, potentially leading to unconventional phenomena like surface uplift, which affects the re-exploitation and reutilization of closed mines. Methods This investigated a mining area in Huainan, Anhui Province as an example to explore the deformation mechanisms, characteristics, and influential factors of the surface uplift of closed mines. Through numerical simulations, this study analyzed the propagation process of surface uplift with an increase in the groundwater level. Accordingly, this study investigated the quantitative impacts of the mining height, groundwater level, and rock strength of the caving zone …

Environmental And Cultural Impacts Of The 8.2 Ka Event In Yenikapı (İstanbul/Türkiye), Ayşi̇n Konak, M. Namik Yalçin

Turkish Journal of Earth Sciences

The Neolithic lifestyle, which began in the 12th millennium BP with the emergence of villages in the core region extendingfrom Iran to central and southeastern Anatolia and Syria, began to spread to neighboring geographies, such as the Marmara region,in the 9th millennium BP. During the 8.2 ka event that occurred between 8300 and 7900 BP, cold and dry conditions prevailed in thenorthern hemisphere. During the winter months, the humidity decreased and cooling of about 6 ± 2 °C was observed. In order totest whether the 8.2 ka event was also effective in the İstanbul region, a set of inorganic geochemical …

Characterization Of Thin Marble Slabs Cut With Roman Water-Powered Stone Saw Millsfrom Western Asia Minor, Hakan Elçi̇, Ramazan Hacimustafaoğlu, Serdar Aybek

Turkish Journal of Earth Sciences

This study examined the mineralogical, petrographic, technological, and material properties of thinly cut marble slabs usedin the flooring and cladding of the frigidarium section of a bath constructed in the 2nd century AD in Metropolis, a city that connectedtwo significant centers in Western Asia Minor-Ephesus and Smyrna-during the Roman period. The study also explains the possibletechniques and methods by which these marble slabs could have been cut so thinly. The thickness of the marble slabs used was closelyrelated to their material properties. Bluish grey, with calcite veins with low flexural strength, containing medium to coarse crystallinecalcite veins, and white marbles …

Classification Of Asia Minor Marbles Based On Crystal Size For Archaeometric Assignment, Ramazan Hacimustafaoğlu, Hakan Elçi̇

Turkish Journal of Earth Sciences

This study was carried out to determine the range of crystal sizes of Asia Minor marbles and to classify the marbles accordingto crystal size. Asia Minor marbles have been used as building stones since ancient times. The literature already includes studies on theircrystal sizes; however, different studies performed on marbles of the same locality have reported different crystal size classes, which hascaused complexity. To eliminate this complexity, this study used multidirectional petrographic analyses on the eight known Asia Minormarbles. Thin sections were photographed under a polarizing microscope, and the crystal sizes of the samples were measured usingcomputerized image analysis. An …

The Integrated Monitoring Of Karst Systems (Miks) Model, Applied In Karst Studies In Bulgaria, Petar Stefanov, Dilyana Stefanova, Peter Nojarov

International Journal of Speleology

Karst is a widespread natural phenomenon that is highly sensitive and very vulnerable to both natural and various anthropogenic impacts. This is due to the complex structure of karst territories, which comprise both surface forms and complex systems of underground cavities. Therefore, the study of karst requires a geosystem approach and integrated monitoring, which gives a real idea of the state of karst geosystems and the impacts of global changes on karstogenesis. The article presents a model of this approach, which is applied in karst studies in Bulgaria. The methodological basis is the original ProKARSTerra paradigm, based on the geosystem …

Smart Cities, Smart Systems: A Comprehensive Review Of System Dynamics Model Applications In Urban Studies In The Big Data Era, Gift Fabolude, Charles Knoble, Anvy Vu, Danlin Yu

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

This paper addresses urban sustainability challenges amid global urbanization, emphasizing the need for innovative approaches aligned with the Sustainable Development Goals. While traditional tools and linear models offer insights, they fall short in presenting a holistic view of complex urban challenges. System dynamics (SD) models that are often utilized to provide holistic, systematic understanding of a research subject, like the urban system, emerge as valuable tools, but data scarcity and theoretical inadequacy pose challenges. The research reviews relevant papers on recent SD model applications in urban sustainability since 2018, categorizing them based on nine key indicators. Among the reviewed papers, …

Increasing Atmospheric Evaporative Demand Across The Tibetan Plateau And Implications For Surface Water Resources, Shiqin Xu, Dennis P. Lettenmaier, Tom R. Mcvicar, Pierre Gentine, Hylke E. Beck, Joshua B. Fisher, Zhongbo Yu, Ningpeng Dong, Akash Koppa, Matthew F. Mccabe

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The Tibetan Plateau, known as the “Asian water tower,” is a hotspot for complex hydroclimatic changes. We reveal that the previously decreasing atmospheric evaporative demand (Eo) trend at the end of the 20th century has reversed over the last two decades. Although both wind stilling and solar dimming have persisted, their effects on Eo rates have been overshadowed by increasing air temperatures and decreasing relative humidity, leading to a net rise in Eo for 1980−2015. Using the empirical “top-down” Budyko approach, we estimate that across seven sub-catchments draining the Tibetan Plateau, a 10% increase in annual-averaged …