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2021

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Articles 16141 - 16170 of 16206

Full-Text Articles in Earth Sciences

Effects Of Hydrological And Climatic Variables On Cyanobacterial Blooms In Four Large Shallow Lakes Fed By The Yangtze River, Jian Huang, Qiujin Xu, Xixi Wang, Hao Ji, Edward J. Quigley, Mohamadali Sharbatmaleki, Simeng Li, Beidou Xi, Biao Sun, Caole Li Jan 2021

Effects Of Hydrological And Climatic Variables On Cyanobacterial Blooms In Four Large Shallow Lakes Fed By The Yangtze River, Jian Huang, Qiujin Xu, Xixi Wang, Hao Ji, Edward J. Quigley, Mohamadali Sharbatmaleki, Simeng Li, Beidou Xi, Biao Sun, Caole Li

Civil & Environmental Engineering Faculty Publications

Shallow lakes, one of the most widespread water bodies in the world, are easily shifted to a new trophic state due to external interferences. Shifting hydrologic conditions and climate change can cause cyanobacterial harmful algal blooms (CyanoHABs) in shallow lakes, which pose serious threats to ecological integrity and human health. This study analyzed the effects of hydrologic and meteorological variables on cyanobacterial blooms in Yangtze-connected lakes (Lake Dongting and Poyang) and isolated lakes (Lake Chao and Tai). The results show that (i) chlorophyll-a (Chl-a) concentration tends to decrease exponentially with increasing relative lake level fluctuations (RLLF) and precipitation, but to …

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Seasonal Dispersal Of Fjord Meltwaters As An Important Source Of Iron And Manganese To Coastal Antarctic Phytoplankton, Kiefer O. Forsch, Lisa Hahn-Woernle, Robert M. Sherrell, Vincent J. Roccanova, Kaixuan Bu, David Burdige, Maria Vernet, Katherine A. Barbeau Jan 2021

Seasonal Dispersal Of Fjord Meltwaters As An Important Source Of Iron And Manganese To Coastal Antarctic Phytoplankton, Kiefer O. Forsch, Lisa Hahn-Woernle, Robert M. Sherrell, Vincent J. Roccanova, Kaixuan Bu, David Burdige, Maria Vernet, Katherine A. Barbeau

OES Faculty Publications

Glacial meltwater from the western Antarctic Ice Sheet is hypothesized to be an important source of cryospheric iron, fertilizing the Southern Ocean, yet its trace-metal composition and factors that control its dispersal remain poorly constrained. Here we characterize meltwater iron sources in a heavily glaciated western Antarctic Peninsula (WAP) fjord. Using dissolved and particulate ratios of manganese to iron in meltwaters, porewaters, and seawater, we show that surface glacial melt and subglacial plumes contribute to the seasonal cycle of iron and manganese within a fjord still relatively unaffected by climate-change-induced glacial retreat. Organic ligands derived from the phytoplankton bloom and …

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Bioactive Trace Metals And Their Isotopes As Paleoproductivity Proxies: An Assessment Using Geotraces-Era Data, T. J. Horner, S. H. Little, T. W. Conway, J. R. Farmer, Jennifer E. Hertzberg, D. J. Janssen, A.J.M. Lough, J.L. Mckay, A. Tessin, S.J.G. Galer, S. L. Jaccard, F. Lacan, A. Paytan, K. Wuttig, Geotraces-Pages Biological Productivity Working Group Members Jan 2021

Bioactive Trace Metals And Their Isotopes As Paleoproductivity Proxies: An Assessment Using Geotraces-Era Data, T. J. Horner, S. H. Little, T. W. Conway, J. R. Farmer, Jennifer E. Hertzberg, D. J. Janssen, A.J.M. Lough, J.L. Mckay, A. Tessin, S.J.G. Galer, S. L. Jaccard, F. Lacan, A. Paytan, K. Wuttig, Geotraces-Pages Biological Productivity Working Group Members

OES Faculty Publications

Phytoplankton productivity and export sequester climatically significant quantities of atmospheric carbon dioxide as particulate organic carbon through a suite of processes termed the biological pump. Constraining how the biological pump operated in the past is important for understanding past atmospheric carbon dioxide concentrations and Earth's climate history. However, reconstructing the history of the biological pump requires proxies. Due to their intimate association with biological processes, several bioactive trace metals and their isotopes are potential proxies for past phytoplankton productivity, including iron, zinc, copper, cadmium, molybdenum, barium, nickel, chromium, and silver. Here, we review the oceanic distributions, driving processes, and depositional …

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Salt Marsh Hydrogeology: A Review, Julia Guimond, Joseph Tamborski Jan 2021

Salt Marsh Hydrogeology: A Review, Julia Guimond, Joseph Tamborski

OES Faculty Publications

Groundwater–surface water exchange in salt marsh ecosystems mediates nearshore salt, nutrient, and carbon budgets with implications for biological productivity and global climate. Despite their importance, a synthesis of salt marsh groundwater studies is lacking. In this review, we summarize drivers mediating salt marsh hydrogeology, review field and modeling techniques, and discuss patterns of exchange. New data from a Delaware seepage meter study are reported which highlight small-scale spatial variability in exchange rates. A synthesis of the salt marsh hydrogeology literature reveals a positive relationship between tidal range and submarine groundwater discharge but not porewater exchange, highlighting the multidimensional drivers of …

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Taxonomic And Nutrient Controls On Phytoplankton Iron Quotas In The Ocean, Benjamin S. Twining, Olga Antipova, P. Dreux Chappell, Natalie R. Cohen, Jeremy E. Jacquot, Elizabeth L. Mann, Adrian Marchetti, Daniel C. Ohnemus, Sara Rauschenberg, Alessandro Tagliabue Jan 2021

Taxonomic And Nutrient Controls On Phytoplankton Iron Quotas In The Ocean, Benjamin S. Twining, Olga Antipova, P. Dreux Chappell, Natalie R. Cohen, Jeremy E. Jacquot, Elizabeth L. Mann, Adrian Marchetti, Daniel C. Ohnemus, Sara Rauschenberg, Alessandro Tagliabue

OES Faculty Publications

Phytoplankton iron contents (i.e., quotas) directly link biogeochemical cycles of iron and carbon and drive patterns of nutrient limitation, recycling, and export. Ocean biogeochemical models typically assume that iron quotas are either static or controlled by dissolved iron availability. We measured iron quotas in phytoplankton communities across nutrient gradients in the Pacific Ocean and found that quotas diverged significantly in taxon‐specific ways from laboratory‐derived predictions. Iron quotas varied 40‐fold across nutrient gradients, and nitrogen‐limitation allowed diatoms to accumulate fivefold more iron than co‐occurring flagellates even under low iron availability. Modeling indicates such “luxury” uptake is common in large regions of …

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A Coastal N₂ Fixation Hotspot At The Cape Hatteras Front: Elucidating Spatial Heterogeneity In Diazotroph Activity Via Supervised Machine Learning, Corday R. Selden, P. Dreux Chappell, Sophie Clayton, Alfonso Macías-Tapia, Peter W. Bernhardt, Margaret R. Mulholland Jan 2021

A Coastal N₂ Fixation Hotspot At The Cape Hatteras Front: Elucidating Spatial Heterogeneity In Diazotroph Activity Via Supervised Machine Learning, Corday R. Selden, P. Dreux Chappell, Sophie Clayton, Alfonso Macías-Tapia, Peter W. Bernhardt, Margaret R. Mulholland

OES Faculty Publications

In the North Atlantic Ocean, dinitrogen (N2) fixation on the western continental shelf represents a significant fraction of basin‐wide nitrogen (N) inputs. However, the factors regulating coastal N2 fixation remain poorly understood, in part due to sharp physico‐chemical gradients and dynamic water mass interactions that are difficult to constrain via traditional oceanographic approaches. This study sought to characterize the spatial heterogeneity of N2 fixation on the western North Atlantic shelf, at the confluence of Mid‐ and South Atlantic Bight shelf waters and the Gulf Stream, in August 2016. Rates were quantified using the 15N2 …

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Constraining 20th‐Century Sea‐Level Rise In The South Atlantic Ocean, Thomas Frederikse, Surendra Adhikari, Tim J. Daley, Sönke Dangendorf, Roland Gehrels, Felix Landerer, Marta Marcos, Thomas L. Newton, Graham Rush, Aimée B.A. Slangen, Guy Wöppelmann Jan 2021

Constraining 20th‐Century Sea‐Level Rise In The South Atlantic Ocean, Thomas Frederikse, Surendra Adhikari, Tim J. Daley, Sönke Dangendorf, Roland Gehrels, Felix Landerer, Marta Marcos, Thomas L. Newton, Graham Rush, Aimée B.A. Slangen, Guy Wöppelmann

OES Faculty Publications

Sea level in the South Atlantic Ocean has only been measured at a small number of tide-gauge locations, which causes considerable uncertainty in 20th-century sea-level trend estimates in this basin. To obtain a better-constrained sea-level trend in the South Atlantic Ocean, this study aims to answer two questions. The first question is: can we combine new observations, vertical land motion estimates, and information on spatial sampling biases to obtain a likely range of 20th-century sea-level rise in the South Atlantic? We combine existing observations with recovered observations from Dakar and a high-resolution sea-level reconstruction based on salt-marsh sediments from the …

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Microbially Induced Sedimentary Structures In Clastic Deposits: Implication For The Prospection For Fossil Life On Mars, Nora Noffke Jan 2021

Microbially Induced Sedimentary Structures In Clastic Deposits: Implication For The Prospection For Fossil Life On Mars, Nora Noffke

OES Faculty Publications

Abundant and well-preserved fossil microbenthos occurs in siliciclastic deposits of all Earth ages, from the early Archean to today. Studies in modern settings show how microbenthos responds to sediment dynamics by baffling and trapping, binding, biostabilization, and growth. Results of this microbial-sediment interaction are microbially induced sedimentary structures (MISS). Successful prospection for rich MISS occurrences in the terrestrial lithological record requires unraveling genesis and taphonomy of MISS, both of which are defined only by a narrow range of specific conditions. These conditions have to coincide with high detectability which is a function of outcrop quality, bedding character, and rock type. …

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Effects Of Tidal Flooding On Estuarine Biogeochemistry: Quantifying Flood-Driven Nitrogen Inputs In An Urban, Lower Chesapeake Bay Sub-Tributary, Alfonso Macías-Tapia, Margaret R. Mulholland, Corday R. Selden, J. Derek Loftis, Peter W. Bernhardt Jan 2021

Effects Of Tidal Flooding On Estuarine Biogeochemistry: Quantifying Flood-Driven Nitrogen Inputs In An Urban, Lower Chesapeake Bay Sub-Tributary, Alfonso Macías-Tapia, Margaret R. Mulholland, Corday R. Selden, J. Derek Loftis, Peter W. Bernhardt

OES Faculty Publications

Sea level rise has increased the frequency of tidal flooding even without accompanying precipitation in many coastal areas worldwide. As the tide rises, inundates the landscape, and then recedes, it can transport organic and inorganic matter between terrestrial systems and adjacent aquatic environments. However, the chemical and biological effects of tidal flooding on urban estuarine systems remain poorly constrained. Here, we provide the first extensive quantification of floodwater nutrient concentrations during a tidal flooding event and estimate the nitrogen (N) loading to the Lafayette River, an urban tidal sub-tributary of the lower Chesapeake Bay (USA). To enable the scale of …

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Radium Isotopes As Submarine Groundwater Discharge (Sgd) Tracers: Review And Recommendations, J. Garcia-Orellana, V. Rodellas, Joseph Tamborski, M. Diego-Feliu, P. Van Beek, Y. Weinstein, M. Charette, A. Alorda-Kleinglass, H.A. Michael, T. Stieglitz, J. Scholten Jan 2021

Radium Isotopes As Submarine Groundwater Discharge (Sgd) Tracers: Review And Recommendations, J. Garcia-Orellana, V. Rodellas, Joseph Tamborski, M. Diego-Feliu, P. Van Beek, Y. Weinstein, M. Charette, A. Alorda-Kleinglass, H.A. Michael, T. Stieglitz, J. Scholten

OES Faculty Publications

Submarine groundwater discharge (SGD) is now recognized as an important process of the hydrological cycle worldwide and plays a major role as a conveyor of dissolved compounds to the ocean. Naturally occurring radium isotopes (Ra-223, Ra-224, Ra-226 and Ra-228) are widely employed geochemical tracers in marine environments. Whilst Ra isotopes were initially predominantly applied to study open ocean processes and fluxes across the continental margins, their most common application in the marine environment has undoubtedly become the identification and quantification of SGD. This review focuses on the application of Ra isotopes as tracers of SGD and associated inputs of water …

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Detrital Neodymium And (Radio)Carbon As Complementary Sedimentary Bedfellows? The Western Arctic Ocean As A Testbed, Melissa S. Schwab, Jörg D. Rickli, Robie W. Macdonald, H. Rodger Harvey, Negar Haghipour, Timothy I. Eglinton Jan 2021

Detrital Neodymium And (Radio)Carbon As Complementary Sedimentary Bedfellows? The Western Arctic Ocean As A Testbed, Melissa S. Schwab, Jörg D. Rickli, Robie W. Macdonald, H. Rodger Harvey, Negar Haghipour, Timothy I. Eglinton

OES Faculty Publications

Interactions between organic and detrital mineral phases strongly influence both the dispersal and accumulation of terrestrial organic carbon (OC) in continental margin sediments. Yet the complex interplay among biological, chemical, and physical processes limits our understanding of how organo-mineral interactions evolve during sediment transfer and burial. In particular, diverse OC sources and complex hydrodynamic processes hinder the assessment of how the partnership of organic matter and its mineral host evolves during supply and dispersal over continental margins. In this study, we integrate new and compiled sedimentological (grain size, surface area), organic (%OC, OC-δ13C, OC-F14C), and inorganic …

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Neodymium Isotope Geochemistry Of A Subterranean Estuary, Darren A. Chevis, T. Jade Mohajerin, Ningfang Yang, Jaye E. Cable, E. Troy Rasbury, Sidney R. Hemming, David J. Burdige, Jonathan B. Martin, Christopher D. White, Karen H. Johannesson Jan 2021

Neodymium Isotope Geochemistry Of A Subterranean Estuary, Darren A. Chevis, T. Jade Mohajerin, Ningfang Yang, Jaye E. Cable, E. Troy Rasbury, Sidney R. Hemming, David J. Burdige, Jonathan B. Martin, Christopher D. White, Karen H. Johannesson

OES Faculty Publications

Rare earth elements (REE) and Nd isotope compositions of surface and groundwaters from the Indian River Lagoon in Florida were measured to investigate the influence of submarine groundwater discharge (SGD) on these parameters in coastal waters. The Nd flux of the terrestrial component of SGD is around 0.7 ± 0.03 μmol Nd/day per m of shoreline across the nearshore seepage face of the subterranean estuary. This translates to a terrestrial SGD Nd flux of 4 ± 0.2 mmol/day for the entire 5,880 m long shoreline of the studied portion of the lagoon. The Nd flux from bioirrigation across the nearshore …

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The Potential For Remote Sensing Measurement Of Dissolved Organic Carbon As A Tool For Metal Risk Assessments, Mickey Nielsen Jan 2021

The Potential For Remote Sensing Measurement Of Dissolved Organic Carbon As A Tool For Metal Risk Assessments, Mickey Nielsen

Theses and Dissertations (Comprehensive)

The biotic ligand model (BLM) is a tool used to quantitatively evaluate how receiving water chemistry affects the bioavailability of metals. Sensitivity testing can be used to understand how the model outputs vary in response to systematic changes in water chemistry inputs. This will allow users of such models to understand how accurate their input parameters must be for a specified level of confidence in the output. Our focus was on dissolved organic carbon (DOC), which is often the most limiting data for application of BLM approaches to metals risk management. To potentially address DOC data limitations remote sensing can …

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The Role Of Symbiotic Algae In The Acclimatization Of Oculina Arbuscula To Ocean Acidification, Erin M. Arneson Jan 2021

The Role Of Symbiotic Algae In The Acclimatization Of Oculina Arbuscula To Ocean Acidification, Erin M. Arneson

College of Graduate Studies: Theses & Dissertations

Ocean acidification (OA) caused by CO2 emissions is projected to decrease seawater pH to 7.6 by 2100. Scleractinian corals are at risk because excess H+ in seawater binds to carbonate (CO32-), reducing its availability for CaCO3 skeletons. The energy demand for skeletal growth increases as pH decreases because corals must actively purge excess H+ from their seawater sourced calcifying fluid to maintain high calcification rates. In scleractinian corals it is hypothesized that photosynthesis by symbiotic algae is critical to meet this increased energy demand. To test this hypothesis, I conducted laboratory and field …

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Evaluating The Impacts Of Dam Construction And Longshore Transport Upon Modern Sedimentation Within The Rio Grande Delta (Texas, U.S.A.), Samantha Moore, Elizabeth A. Heise, Marty Grove, Anthony Reisinger, Jude A. Benavides Jan 2021

Evaluating The Impacts Of Dam Construction And Longshore Transport Upon Modern Sedimentation Within The Rio Grande Delta (Texas, U.S.A.), Samantha Moore, Elizabeth A. Heise, Marty Grove, Anthony Reisinger, Jude A. Benavides

School of Earth, Environmental, & Marine Sciences Faculty Publications

The modern Rio Grande delta system has experienced a century of dam construction, water removal for irrigation and municipal use, and land use modifications that have dramatically reduced its sediment load. This study examines whether damming has sufficiently limited delivery of upstream sediment to permit locally eroded sources and/or littoral transport along the coast to influence the provenance signal of the Rio Grande delta. Changes in sediment provenance within the Rio Grande’s delta can be detected and quantified by measurement of detrital zircon Uranium–lead dating age distributions. Previous provenance studies indicate that modern Rio Grande river sand upstream of Falcon …

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New Amphibian And Reptile Distribution Records From Eastern South Dakota, Usa, Drew R. Davis Jan 2021

New Amphibian And Reptile Distribution Records From Eastern South Dakota, Usa, Drew R. Davis

School of Earth, Environmental, & Marine Sciences Faculty Publications

Over recent years, the continued collection of voucher specimens has helped to better document the distributions of South Dakota’s amphibians and reptiles. Despite large increases in our knowledge of these distributions, it remains clear that gaps in our understanding remain. Here, I report 17 new county records of six species of amphibians and reptiles from eastern South Dakota (east of the Missouri River) that are the result of fieldwork conducted in September 2020. The majority of these records are from the northern portions of the James River Lowland, Missouri Coteau, and Drift Plains ecoregions (Bryce et al. 1998), which are …

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Importance Of Low-Relief Nursery Habitat For Reef Fishes, Michael A. Dance, Ray R. Rooker, Richard Kline, Antonietta Quigg, Gregory R. Stunz, R. J. David Wells, Kirsten Lara, Jessica Lee, Bobbie Suarez Jan 2021

Importance Of Low-Relief Nursery Habitat For Reef Fishes, Michael A. Dance, Ray R. Rooker, Richard Kline, Antonietta Quigg, Gregory R. Stunz, R. J. David Wells, Kirsten Lara, Jessica Lee, Bobbie Suarez

School of Earth, Environmental, & Marine Sciences Faculty Publications

Coastal restoration projects to mitigate environmental impacts have increased global demand for sand resources. Unfortunately, these resources are often extracted from sand/shell banks on the inner continental shelf, resulting in significant alteration or loss of low-relief reefs in coastal oceans. Experimental reefs (oyster shell, limestone rubble, composite) were deployed in the western Gulf of Mexico to assess their potential value as nurseries for newly settled reef fishes. Occurrence, abundance, and species richness of juvenile fishes were significantly higher on all three types of low-relief reefs compared with unconsolidated sediment. Moreover, reefs served as nursery habitat for a range of reef …

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Impact Of Rheology Models On Horizontal Well Polymer Flooding In A Heavy Oil Reservoir On Alaska North Slope: A Simulation Study, Jianqiao Leng, Mingzhen Wei, Baojun Bai, Randall S. Seright, Yin Zhang, David Cercone, Samson Ning Jan 2021

Impact Of Rheology Models On Horizontal Well Polymer Flooding In A Heavy Oil Reservoir On Alaska North Slope: A Simulation Study, Jianqiao Leng, Mingzhen Wei, Baojun Bai, Randall S. Seright, Yin Zhang, David Cercone, Samson Ning

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Polymer rheology can have either a positive or a negative effect on polymer flooding performance under varied circumstances. Many researchers have studied the effect of polymer rheology in a vertical well, but no field scale studies have been conducted to investigate whether polymer rheology is beneficial to polymer flooding in heavy oil reservoirs developed by horizontal wells. In this paper, we conducted a numerical simulation study to examine the effect of HPAM polymer rheology on a polymer flooding pilot, which is the first-ever project conducted on a heavy oil reservoir from Alaska North Slope (ANS) developed by horizontal wells. Three …

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First Ever Polymer Flood Field Pilot To Enhance The Recovery Of Heavy Oils On Alaska's North Slope Pushing Ahead One Year Later, Abhijit Dandekar, Baojun Bai, John Barnes, Dave Cercone, Jared Ciferno, Reid Edwards, Samson Ning, Walbert Schulpen, Randy Seright, Brent Sheets, Dongmei Wang, Yin Zhang Jan 2021

First Ever Polymer Flood Field Pilot To Enhance The Recovery Of Heavy Oils On Alaska's North Slope Pushing Ahead One Year Later, Abhijit Dandekar, Baojun Bai, John Barnes, Dave Cercone, Jared Ciferno, Reid Edwards, Samson Ning, Walbert Schulpen, Randy Seright, Brent Sheets, Dongmei Wang, Yin Zhang

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

In June 2018 the team embarked on an ambitious project to address the slow development pace of Alaska's 20+ billion barrels heavy oil resource via the first ever polymer flood pilot. Following the successful commencement of the pilot in August 2018, the field demonstration, supporting laboratory experiments and numerical simulation have steadily progressed. A significant amount of valuable data and lessons learned have been collected and are reported in this paper. The ongoing pilot and the research activities is making headway toward the primary objective of validating the use of polymer flooding for extracting heavy oil in Alaska's challenging environment. …

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Creating Synthetic Analogs Of Fluorescent Speleothems In Wind Cave As An Astrobiological Model Cave, Teresa Feldman Jan 2021

Creating Synthetic Analogs Of Fluorescent Speleothems In Wind Cave As An Astrobiological Model Cave, Teresa Feldman

Honors Program Theses

The wind cave system represents a unique environment on Earth where the direct interplay of organic chemistry on the surface can possibly be traced to extremophiles living hundreds of meters below the surface. In many cases, minerals and organics from the surface become trapped in calcite formations creating fluorescent minerals. To understand the environment giving rise to the fluorescent minerals in Wind Cave, laboratory analogs of the calcite crystals found within the Wind Cave National Park cavern were synthesized and analyzed using SEM and fluorescence spectroscopy. This data was compared to the fluorescence and XRF data collected from speleothems in …

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New Hampshire Continental Shelf Historical Geophysical Database: 1971 To 2015 - Sediment Data, Larry G. Ward, Rachel C. Morrison, Zachary S. Mcavoy, Maxlimer Coromoto Vallee-Anziani Jan 2021

New Hampshire Continental Shelf Historical Geophysical Database: 1971 To 2015 - Sediment Data, Larry G. Ward, Rachel C. Morrison, Zachary S. Mcavoy, Maxlimer Coromoto Vallee-Anziani

Data Catalog

The UNH CCOM/JHC "New Hampshire Continental Shelf Historical Geophysical Database: 1971 to 2015 - Sediment Data" contains sediment grain size data and classifications from studies conducted between 1971 and 2015. In total, grain size data was available for 725 bottom sediment samples. Included are sample identification information, station and sample characteristics, sediment classifications, grain size statistics, and grain size distribution. Not all of these parameters were available for every study. Samples were analyzed with standard sieve and pipette analyses after Folk (1980). The sediment grain size classifications include: CMECS (Coastal and Marine Ecological Classification Standard; FGDC, 2012); Gradistat (Blot and …

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Founding Monsters Tales, Maggie Colangelo, Bernard Means Jan 2021

Founding Monsters Tales, Maggie Colangelo, Bernard Means

Founding Monsters

The creative team behind the Founding Monsters comic book—Maggie Colangelo and Dr. Bernard K. Means—bring you Founding Monsters Tales. Founding Monsters Tales features all-new art by Maggie and explores and expands on themes in Founding Monsters. Meet again Moses Williams, an enslaved servant of the Peale family who not only helped reconstruct the first mastodon skeleton, but was an unheralded artist in his own right. Find out whether mastodons were meat eaters, and how they differed from mammoths. Learn whether Thomas Jefferson was correct in his interpretation of what he called “the great claw.” Discover what Jefferson thought …

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Founding Monsters, Maggie Colangelo, Bernard Means Jan 2021

Founding Monsters, Maggie Colangelo, Bernard Means

Founding Monsters

The Founding Monsters comic book was created as a science-friendly graphical storytelling framework that tells the story of the Founding Fathers and their obsession with prehistoric megafauna, especially mastodons and giant ground sloths. Founding Monsters combines sequential art (e.g. comic book style) with historical and scientific data. The first mastodon (Mammut americanum) fossils were found in New York in the early 18th century. Later in the 18th century, Thomas Jefferson was sent fossils from what is now West Virginia for what were eventually identified as bones from a giant ground sloth (Megalonyx jeffersoni). The founding fathers, …

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Structural And Thermochronologic Evidence Of Paleogene-Neogene Faulting And Exhumation Of The Klamath Mountain Province, Taylor C. Team Jan 2021

Structural And Thermochronologic Evidence Of Paleogene-Neogene Faulting And Exhumation Of The Klamath Mountain Province, Taylor C. Team

Cal Poly Humboldt theses and projects

The Klamath Mountains Province (KMP), located at the southern end of the forearc of the Cascadia Subduction Zone, displays a distinct topographic and geologic signature. Compared to the forearc in the north, the KMP comprises Paleozoic-Mesozoic basement rocks with relatively high modern elevation and relief. This study investigates the pattern of rock cooling in the KMP by using thermochronology on plutons exhumed by faults and plutons outside of mapped faults. In this study, I target three regions in the KMP: the Ashland pluton offset by the Siskiyou Summit fault in the northeast KMP, the Grayback pluton in the northwest KMP, …

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Stress-State Dependency Of The Deformation Ratio Of Quasi-Elastic Granular Soils Under Cyclic Loading -- Supporting Information, Pingxin Xia, Longtan Shao, Wen Deng Jan 2021

Stress-State Dependency Of The Deformation Ratio Of Quasi-Elastic Granular Soils Under Cyclic Loading -- Supporting Information, Pingxin Xia, Longtan Shao, Wen Deng

Research Data

Poisson’s ratio, besides its transverse-axial strain ratio definition, also plays a significant role in traditional elastic theory as an elastic constant. However, this elastic role of Poisson’s ratio faces a challenge when applied to quasi-elastic granular soils. A so-called “deformation ratio” is therefore introduced and measured in this paper for quasi-elastic granular soils. With the same definition of the transverse-axial strain ratio as Poisson’s ratio, the stress-state dependency of the deformation ratio and the break-down of conversion relationship of elastic constants are investigated under cyclic triaxial tests. The results show that Poisson’s ratio is consistent with deformation ratio only in …

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Beaver Moderated Fire Resistance In The North Cascades And Potential For Climate Change Adaptation, Joseph John Weirich Iii Jan 2021

Beaver Moderated Fire Resistance In The North Cascades And Potential For Climate Change Adaptation, Joseph John Weirich Iii

EWU Masters Thesis Collection

Climate change and fire suppression have altered historic fire regimes, creating conditions for larger, more intense fires. Intense burns can alter watershed hydrology, increasing the potential for harmful channel incision, which impairs riparian ecosystem function by lowering the water table, disconnecting floodplains from aquatic environments. However, wetlands and functioning riparian zones can reduce burn intensity. Beaver, with their unique ability to build dams, can restore incised and degraded streams, store water, and expand wetland environments, potentially decreasing wildfire intensity, fire spread and create fire breaks across the landscape. My objective was to test the hypothesis that beaver impoundments increase landscape …

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Moving The Needle On Prairie Conservation: A Palouse Prairie Restoration/Reconstruction Needs Assessment And The Effect Of Intra-Annual Soil Moisture Changes On Balsamroot Seedling Establishment, Sarah Hill Jan 2021

Moving The Needle On Prairie Conservation: A Palouse Prairie Restoration/Reconstruction Needs Assessment And The Effect Of Intra-Annual Soil Moisture Changes On Balsamroot Seedling Establishment, Sarah Hill

EWU Masters Thesis Collection

The Palouse prairie of Eastern Washington and Western Idaho is one of the most endangered ecosystems in the United States. After 140 years of intensive agriculture, less than 1% of prairie habitat remains, making Palouse prairie conservation and restoration a critical need. This study sought to: 1) conduct a thorough needs assessment for Palouse prairie restoration and reconstruction, identifying challenges and opportunities that when addressed, could increase Palouse prairie restoration successes, and 2) gain insight into the effects of intra-annual soil moisture fluctuations on the seedling establishment of Arrowleaf balsamroot (Balsamorhiza sagittata), since establishment of slow growing perennial species like …

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Bryozoan Taxa Of The Toroweap Formation Of Clark County, Nevada, Amy Joy Hess Jan 2021

Bryozoan Taxa Of The Toroweap Formation Of Clark County, Nevada, Amy Joy Hess

EWU Masters Thesis Collection

No abstract provided.

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The Impact Of Unsaturated Zone Thickness On The Severity Of Saltwater Intrusion In Coastal Aquifers From Overtopping, Dennis Jesse Carpinello Jan 2021

The Impact Of Unsaturated Zone Thickness On The Severity Of Saltwater Intrusion In Coastal Aquifers From Overtopping, Dennis Jesse Carpinello

Graduate Theses, Dissertations, and Problem Reports (ETD)

Storm-surge inundation and wave overwash, collectively overtopping, causes the land surface to be inundated with seawater, resulting in vertical infiltration of saline waters into underlying coastal aquifers, which can have severe consequences on freshwater resources. Unsaturated zone thickness plays an important role in determining the severity of saltwater contamination resulting from an overtopping event. This study uses numerical modeling to investigate vertical saltwater infiltration and salinization, and the subsequent aquifer recovery to overtopping events for coastal aquifers with different unsaturated zone thicknesses. Groundwater models were developed using the numerical code SUTRA to solve saturated-unsaturated, density-dependent groundwater flow and solute …

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Evaluation Of A Low-Cost Uas And Phenocams For Measuring Grapevine Greenness, Timothy J. Hoheneder Jan 2021

Evaluation Of A Low-Cost Uas And Phenocams For Measuring Grapevine Greenness, Timothy J. Hoheneder

Graduate Theses, Dissertations, and Problem Reports (ETD)

Unpersoned aerial systems (UAS) could provide winegrowers with the potential to monitor vineyard productivity with ultra-high-resolution imagery and low operational costs. This ability could prove particularly valuable in the challenging cool-climate viticultural areas of Appalachia. Especially in this mountainous region of increasingly variable microclimates, there could be of great value from an ability to use UAS-measured greenness to monitor wine grape phenology and predict harvest quality and quantity. In this study, I assess how UAS-measured greenness relates to three complementary measures of field-based: leaf angle measurements, phenocam measured greenness, and leaf spectral measurements of greenness. After correlating these field-based measures …

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