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University of Nebraska - Lincoln

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Articles 91 - 120 of 1807

Full-Text Articles in Geology

Influences Of Seasonality And Habitat Quality On Great Lakes Coastal Wetland Fish Community Composition And Diets, Sara N. Diller, Anna M. Harrison, Kurt P. Kowalski, Valerie J. Brady, Jan J. H. Ciborowski, Matthew J. Cooper, Joshua D. Dumke, Joseph P. Gathman, Carl R. Ruetz Iii, Donald G. Uzarski, Douglas A. Wilcox, Jeffrey S. Schaeffer May 2022

Influences Of Seasonality And Habitat Quality On Great Lakes Coastal Wetland Fish Community Composition And Diets, Sara N. Diller, Anna M. Harrison, Kurt P. Kowalski, Valerie J. Brady, Jan J. H. Ciborowski, Matthew J. Cooper, Joshua D. Dumke, Joseph P. Gathman, Carl R. Ruetz Iii, Donald G. Uzarski, Douglas A. Wilcox, Jeffrey S. Schaeffer

United States Geological Survey: Staff Publications

Great Lakes coastal wetlands (GLCW) have been severely degraded by anthropogenic activity over the last several decades despite their critical role in fish production. Many Great Lakes fish species use coastal wetland habitats for spawning, feeding, shelter, and nurseries throughout the year. The goal of our study was to compare GLCW fish community composition in the spring, summer, and fall months and investigate how water quality relates to fish diversity, the presence of functional groups, and juvenile fish diets. We summarized fish data collected from GLCW across the basin and used the coastal wetland monitoring program’s water quality-land use indicator …


A Critical Review Of Bioaccumulation And Biotransformation Of Organic Chemicals In Birds, Dave T. F. Kuo, Barnett A. Rattner, Sarah C. Marteinson, Robert Letcher, Kim J. Fernie, Gabriele Treu, Markus Deutsch, Mark S. Johnson, Sandrine Deglin, Michelle Embry May 2022

A Critical Review Of Bioaccumulation And Biotransformation Of Organic Chemicals In Birds, Dave T. F. Kuo, Barnett A. Rattner, Sarah C. Marteinson, Robert Letcher, Kim J. Fernie, Gabriele Treu, Markus Deutsch, Mark S. Johnson, Sandrine Deglin, Michelle Embry

United States Geological Survey: Staff Publications

A literature review of bioaccumulation and biotransformation of organic chemicals in birds was undertaken, aiming to support scoping and prioritization of future research. The objectives were to characterize available bioaccumulation/ biotransformation data, identify knowledge gaps, determine how extant data can be used, and explore the strategy and steps forward. An intermediate approach balanced between expediency and rigor was taken given the vastness of the literature. Following a critical review of >500 peer-reviewed studies, >25,000 data entries and 2 million information bytes were compiled on >700 organic compounds for ~ 320 wild species and 60 domestic breeds of birds. These data …


Nutrient Restoration Of A Large, Impounded, Ultra-Oligotrophic Western River To Recover Declining Native Fishes, Ryan S. Hardy, Tyler J. Ross, Kevin N. Mcdonnell, Michael C. Quist, Charlie Holderman, Bryan S. Stevens May 2022

Nutrient Restoration Of A Large, Impounded, Ultra-Oligotrophic Western River To Recover Declining Native Fishes, Ryan S. Hardy, Tyler J. Ross, Kevin N. Mcdonnell, Michael C. Quist, Charlie Holderman, Bryan S. Stevens

United States Geological Survey: Staff Publications

Declines in many fish populations in large, western rivers have been primarily attributed to the anthropogenic reduction of nutrient inputs and subsequent impacts to the food web. The largest known river fertilization program was implemented starting in 2005 on the Kootenai River in northern Idaho to restore resident fisheries. Annual electrofishing surveys were conducted at multiple sites in Idaho and Montana before and during nutrient addition to evaluate assemblage and population-level responses. Although few responses in fish assemblage structure were observed, the addition of liquid ammonium polyphosphate fertilizer (3 μg/L) to the Kootenai River increased fish abundance and biomass over …


Air, Land, And Water Variables Associated With The First Appearance And Current Spatial Distribution Of Toxic Prymnesium Parvum Blooms In Reservoirs Of The Southern Great Plains, Usa, Shisbeth Tábora-Sarmiento, Reynaldo Patiño, Carlos Portillo-Quintero, Cade Coldren Apr 2022

Air, Land, And Water Variables Associated With The First Appearance And Current Spatial Distribution Of Toxic Prymnesium Parvum Blooms In Reservoirs Of The Southern Great Plains, Usa, Shisbeth Tábora-Sarmiento, Reynaldo Patiño, Carlos Portillo-Quintero, Cade Coldren

United States Geological Survey: Staff Publications

This study examined the association of air, land, and water variables with the first historical occurrence and current distribution of toxic Prymnesium parvum blooms in reservoirs of the Brazos River and Colorado River, Texas (USA). One impacted and one reference reservoir were selected per basin. Land cover and use variables were estimated for the whole watershed (WW) and a 0.5-km zone on either side of streams (near field, NF). Variables were expressed in annual values. Principal component and trend analyses were used to determine (1) differences in environmental conditions before and after the 2001 onset of toxic blooms in impacted …


Spatial And Temporal Distribution And Habitat Selection Of Native Yellowstone Cutthroat Trout And Nonnative Utah Chub, Darcy K. Mccarrick, Jeffrey C. Dillon, Brett High, Michael C. Quist Apr 2022

Spatial And Temporal Distribution And Habitat Selection Of Native Yellowstone Cutthroat Trout And Nonnative Utah Chub, Darcy K. Mccarrick, Jeffrey C. Dillon, Brett High, Michael C. Quist

United States Geological Survey: Staff Publications

Henrys Lake, Idaho, is a renowned trophy trout fishery that faces an uncertain future following the establishment of Utah Chub (UTC) Gila atraria. Utah Chub were first documented in the lake in 1993 and have become abundant over the past two decades. Little is known about the ecology of UTC, but they typically have negative effects on salmonids in systems where they have been introduced. We sought to fill knowledge gaps in UTC ecology and provide insight on potential interactions with Yellowstone Cutthroat Trout (YCT) Oncorhynchus clarkii bouvieri. Ninety-four YCT and 95 UTC were radio-tagged in spring 2019 …


Comparing Satellite Vs Marine Potential Fields Data Over The Bathymetrists Seamounts, Alexa Fernandez, Irina Filina Apr 2022

Comparing Satellite Vs Marine Potential Fields Data Over The Bathymetrists Seamounts, Alexa Fernandez, Irina Filina

UNL Student Research Days Posters, Graduate

The Bathymetrists Seamounts (BSM) are located north of the Sierra Leone Rise (SLR) in the mid-Atlantic Ocean. The seamounts reside on oceanic crust that is 105 to 45 million years old. However, dredging over the Bathymetrists Seamounts dated rocks at ~40 Myr. The general trend of the seamounts contradicts the eastward motion of the African tectonic plate. The origin and tectonic history of the Bathymetrists Seamounts remains debated in literature. Potential fields (gravity and magnetic) data can provide important insight into the formation and evolution of the seamounts. The purpose of this study is to compare available gravity and magnetic …


Ignoring Species Availability Biases Occupancy Estimates In Single-Scale Occupancy Models, Graziella V. Direnzo, David A. W. Miller, Evan H. C. Grant Apr 2022

Ignoring Species Availability Biases Occupancy Estimates In Single-Scale Occupancy Models, Graziella V. Direnzo, David A. W. Miller, Evan H. C. Grant

United States Geological Survey: Staff Publications

  1. Most applications of single-scale occupancy models do not differentiate between availability and detectability, even though species availability is rarely equal to one. Species availability can be estimated using multi-scale occupancy models; however, for the practical application of multi-scale occupancy models, it can be unclear what a robust sampling design looks like and what the statistical properties of the multi-scale and single-scale occupancy models are when availability is less than one.
  2. Using simulations, we explore the following common questions asked by ecologists during the design phase of a field study: (Q1) what is a robust sampling design for the multi-scale occupancy …


Processing Seismic, Gravity And Magnetic Data Over Diebold Knoll On Juan De Fuca Plate, Md Ariful Islam, Irina Filina Apr 2022

Processing Seismic, Gravity And Magnetic Data Over Diebold Knoll On Juan De Fuca Plate, Md Ariful Islam, Irina Filina

UNL Student Research Days Posters, Graduate

The Juan de Fuca plate is subducting beneath the North American plate along the Cascadia Subduction Zone. The CSZ is associated with multiple earthquakes, although compared to other subduction zones, it is less active. Many studies suggest that subduction will cause major mega thrust earthquake in near future, while others oppose this view. This project is focused on the Diebold Knoll on the JdF plate Various geophysical methods will be integrated to determine its origin and tectonic history.


Informing Management Of Henrys Lake, Idaho, Using An Integrated Catch-At-Age Model, Joshua L. Mccormick, Jennifer Vincent, Brett High, Darcy K. Mccarrick, Michael C. Quist Mar 2022

Informing Management Of Henrys Lake, Idaho, Using An Integrated Catch-At-Age Model, Joshua L. Mccormick, Jennifer Vincent, Brett High, Darcy K. Mccarrick, Michael C. Quist

United States Geological Survey: Staff Publications

Henrys Lake, Idaho, supports a popular fishery for Yellowstone Cutthroat Trout Oncorhynchus clarkii bouvieri and Yellowstone Cutthroat Trout × Rainbow Trout O. mykiss hybrids. A majority of the adult population of fish in Henrys Lake are of hatchery origin that were stocked as fingerlings. The fishery is closed to angling during the late winter and spring months, but fisheries managers are considering opening the fishery year-round with catch-and-release- only regulations or with a two-fish bag limit during the extended season. However, there is concern that the proposed management actions may negatively affect the current fishery. Therefore, we developed an integrated …


Toward The Understanding Of The 2018 Arnold, Ne Earthquake Cluster: Relocation Of Hypocenters And Establishment Of New Gravity Base Stations, Kris Guthrie Mar 2022

Toward The Understanding Of The 2018 Arnold, Ne Earthquake Cluster: Relocation Of Hypocenters And Establishment Of New Gravity Base Stations, Kris Guthrie

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

In 2018, 27 unexpected earthquakes occurred in central Nebraska near Arnold. These earthquakes have no readily apparent cause and no evidence of the responsible fault system is seen at the surface. A joint analysis of vintage, regional gravity and magnetic datasets before the first earthquake revealed a lineament that could represent a pre-existing fault system. New high resolution potential fields data are needed to confidently map the subsurface features around the cluster. To design a survey and collect the data, the following tasks need to be addressed: [1] The earthquakes’ hypocenters need to be improved (relocated) to increase the efficiency …


Nebraska Statewide Groundwater-Level Monitoring Report 2021, Aaron R. Young, Mark E. Burbach, Leslie M. Howard, Sue Olafsen Lackey, Robert Matthew Joeckel Mar 2022

Nebraska Statewide Groundwater-Level Monitoring Report 2021, Aaron R. Young, Mark E. Burbach, Leslie M. Howard, Sue Olafsen Lackey, Robert Matthew Joeckel

Conservation and Survey Division: Faculty and Staff Publications

This report is a synthesis of groundwater-level monitoring programs in Nebraska. It is a continuation of the series of annual reports and maps produced by the Conservation and Survey Division (CSD) of the University of Nebraska in cooperation with the U.S. Geological Survey (USGS) since the 1950s. Groundwater-level monitoring began in Nebraska in 1930 in an effort to survey the state’s groundwater resources and to observe changes in its availability on a continuing basis. The CSD and USGS cooperatively developed, maintained, and operated an observation-well network throughout the state. These two agencies were responsible for collecting and archiving this information, …


Paradigm Versus Paradox On The Prairie: Testing Competing Stream Fish Movement Frameworks Using An Imperiled Great Plains Minnow, Zachary D. Steffensmeier, Maeghen Wedgeworth, Lauren Yancy, Noah Santee, Shannon K. Brewer, Joshuah S. Perkin Feb 2022

Paradigm Versus Paradox On The Prairie: Testing Competing Stream Fish Movement Frameworks Using An Imperiled Great Plains Minnow, Zachary D. Steffensmeier, Maeghen Wedgeworth, Lauren Yancy, Noah Santee, Shannon K. Brewer, Joshuah S. Perkin

United States Geological Survey: Staff Publications

Background: Movement information can improve conservation of imperiled species, yet movement is not quantified for many organisms in need of conservation. Prairie chub (Macrhybopsis australis) is a regionally endemic freshwater fish with unquantified movement ecology and currently considered for listing under the Endangered Species Act. The purpose of this study was to test competing ecological theories for prairie chub movement, including the colonization cycle hypothesis (CCH) that posits adults must make upstream movements to compensate for downstream drift at early life stages, and the restricted movement paradigm (RMP) that describes populations as heterogeneous mixes of mostly stationary …


Fluids And Melts At The Magmatic-Hydrothermal Transition, Recorded By Unidirectional Solidification Textures At Saginaw Hill, Arizona, Usa, Wyatt M. Bain, Pilar Lecumberri-Sanchez, Erin E. Marsh, Matthew Steele-Macinnis Feb 2022

Fluids And Melts At The Magmatic-Hydrothermal Transition, Recorded By Unidirectional Solidification Textures At Saginaw Hill, Arizona, Usa, Wyatt M. Bain, Pilar Lecumberri-Sanchez, Erin E. Marsh, Matthew Steele-Macinnis

United States Geological Survey: Staff Publications

Fluid exsolution and melt evolution at the magmatic-hydrothermal transition are critical processes driving the metal enrichment of porphyry systems. Coeval fluid and melt inclusion assemblages in unidirectional solidification textures (USTs) at Saginaw Hill—a small, porphyry Cu system in southwestern Arizona—record a dynamic and repetitious process of fluid accumulation and release. The cores of quartz crystals throughout the UST bands host coeval silicate melt and brine inclusions but lack vapor-rich inclusions. This could indicate preferential expulsion of vapor and trapping of high-density brine during episodes of fracturing or the direct exsolution of single-phase high-salinity brine from the silicate melt. In contrast, …


Baseflow And Water Resilience Variability In Two Water Management Units In Southeastern Brazil, Lucas Vituri Santarosa, Didier Gastmans, Troy E. Gilmore, Jan Boll, Sebastian Balbin Betancur, Vitor Fidelis Monteiro Gonçalves Jan 2022

Baseflow And Water Resilience Variability In Two Water Management Units In Southeastern Brazil, Lucas Vituri Santarosa, Didier Gastmans, Troy E. Gilmore, Jan Boll, Sebastian Balbin Betancur, Vitor Fidelis Monteiro Gonçalves

Conservation and Survey Division: Faculty and Staff Publications

Changes in climate and water demand in densely populated regions increasingly affect hydrological systems, and, in turn, impact socioeconomic conditions. In this case study, we identify how the hydrogeological frameworks of two water resource management units, Tietê-Jacaré (TJ) and Piracicaba-Capivari-Jundiaí (PCJ) in Sao Paulo state (Brazil), control the baseflow processes and resilience in the face of streamflow fluctuations in response to anthropogenic activities and climate variation. The results reveal between 40% and 75% contributions of baseflow to total streamflow in basins overlying crystalline and sedimentary aquifers. The basins in PCJ which mostly overly crystalline aquifers, have shorter water residence times …


Coastal Paleogeography Of The Pacific Northwest, Usa, For The Last 12,000 Years Accounting For Three-Dimensional Earth Structure, Jorie Clark, Jay R. Alder, Marisa Borreggine, Jerry X. Mitrovica, Konstantin Latychev Jan 2022

Coastal Paleogeography Of The Pacific Northwest, Usa, For The Last 12,000 Years Accounting For Three-Dimensional Earth Structure, Jorie Clark, Jay R. Alder, Marisa Borreggine, Jerry X. Mitrovica, Konstantin Latychev

United States Geological Survey: Staff Publications

Predictive modeling of submerged archaeological sites requires accurate sea-level predictions in order to reconstruct coastal paleogeography and associated geographic features that may have influenced the locations of occupation sites such as rivers and embayments. Earlier reconstructions of the paleogeography of parts of the western U.S. coast used an assumption of eustatic sea level, but this neglects the large spatial variations in relative sea level (RSL) associated with glacial isostatic adjustment (GIA) and tectonics. Subsequent work using a one-dimensional (1-D) solid Earth model showed that reconstructions that accounted for GIA result in significant differences from those based on eustatic sea level. …


Coastal Paleogeography Of The Pacific Northwest, Usa, For The Last 12,000 Years Accounting For Three-Dimensional Earth Structure, Jorie Clark, Jay R. Alder, Marisa Borreggine, Jerry X. Mitrovica, Konstantin Latychev Jan 2022

Coastal Paleogeography Of The Pacific Northwest, Usa, For The Last 12,000 Years Accounting For Three-Dimensional Earth Structure, Jorie Clark, Jay R. Alder, Marisa Borreggine, Jerry X. Mitrovica, Konstantin Latychev

United States Geological Survey: Staff Publications

Predictive modeling of submerged archaeological sites requires accurate sea-level predictions in order to reconstruct coastal paleogeography and associated geographic features that may have influenced the locations of occupation sites such as rivers and embayments. Earlier reconstructions of the paleogeography of parts of the western U.S. coast used an assumption of eustatic sea level, but this neglects the large spatial variations in relative sea level (RSL) associated with glacial isostatic adjustment (GIA) and tectonics. Subsequent work using a one-dimensional (1-D) solid Earth model showed that reconstructions that accounted for GIA result in significant differences from those based on eustatic sea level. …


2022 Nebraska Water Leaders Academy Final Report, Mark E. Burbach, Robert Matthew Joeckel, Brooke Mott, Gina S. Matkin Jan 2022

2022 Nebraska Water Leaders Academy Final Report, Mark E. Burbach, Robert Matthew Joeckel, Brooke Mott, Gina S. Matkin

Conservation and Survey Division: Faculty and Staff Publications

Fifteen participants completed the 2022 Water Leaders Academy bringing the total number of graduates to 168 since the inception of the program in 2011. Assessments of participants’ transformational leadership skills, champion of innovation skills, water knowledge, engagement with water issues, civic capacity, entrepreneurial leadership behaviors, and boundary spanning skills increased significantly over the course of the year, according to both the participants and their raters. Feedback from the participants was highly positive and constructive. Academy planners are addressing participant concerns. Results of the program assessment indicate that the curriculum is meeting Academy objectives. Therefore, only minor changes are planned for …


Amphibians And Reptiles Of Nebraska Coloring Pages, John Lokke Jan 2022

Amphibians And Reptiles Of Nebraska Coloring Pages, John Lokke

Conservation and Survey Division: Faculty and Staff Publications

Black and white images from original art by John Lokke. Suitable for coloring pages. Published by the Nebraska Maps & More Store at the School of Natural Resources, University of Nebraska - Lincoln.


Strange Stones Of Skull Creek: Basalt Glacial Erratics And Omars In Eastern Nebraska, Robert M. Joeckel, Jesse T. Korus, Judith Turk, C. C. Arps, N. V. Arps, Leslie M. Howard Jan 2022

Strange Stones Of Skull Creek: Basalt Glacial Erratics And Omars In Eastern Nebraska, Robert M. Joeckel, Jesse T. Korus, Judith Turk, C. C. Arps, N. V. Arps, Leslie M. Howard

Conservation and Survey Division: Faculty and Staff Publications

We describe unusual stream- reworked glacially transported rocks (erratics) from a locality 50 km east of the limit of all pre- Illinoian (pre- 190 ka) Pleistocene glaciations in the central USA. Almost all these erratics consist of the igneous rock basalt, and of those, the vast majority have at least one fl at, smooth face. Some have two or more such faces that meet at obtuse angles along one or more well- defi ned, straight edges. We attribute these features, as well as laminations, plumose marks, and other features, to columnar jointing in ancient lava fl ows and shallow intrusions. …


The Impact Of Sampling Methodology On Soil Bulk Density Measurement By The Clod Method, Aldi J. Airori, Trinity Baker, Judith Turk Jan 2022

The Impact Of Sampling Methodology On Soil Bulk Density Measurement By The Clod Method, Aldi J. Airori, Trinity Baker, Judith Turk

Conservation and Survey Division: Faculty and Staff Publications

The clod method is a widely used and accurate bulk density method. However, its use is limited to sampling from soil pits. This study was conducted to: 1) determine whether clods collected from cores provide similar bulk density measurements to those collected from soil pits and 2) evaluate the impact of various clod bulk density methods on carbon stock calculation. Clods were collected from soil pits, 5.1 cm soil cores, and 8.9 cm soil cores. Three-dimensional laser scanning was used to measure the volume of the soil clods before and after oven-drying and bulk density was calculated as the dry …


Mis 5e Sea-Level History Along The Pacific Coast Of North America, Daniel R. Muhs Jan 2022

Mis 5e Sea-Level History Along The Pacific Coast Of North America, Daniel R. Muhs

United States Geological Survey: Staff Publications

The primary last interglacial, marine isotope substage (MIS) 5e records on the Pacific coast of North America, from Washington (USA) to Baja California Sur (Mexico), are found in the deposits of erosional marine terraces. Warmer coasts along the southern Golfo de California host both erosional marine terraces and constructional coral reef terraces. Because the northern part of the region is tectonically active, MIS 5e terrace elevations vary considerably, from a few meters above sea level to as much as 70m above sea level. The primary paleo-sea-level indicator is the shoreline angle, the junction of the wave-cut platform with the former …


Interaction With Augmented Reality Sandbox Does Not Produce Greater Gains In Topographic Map Skills For Undergraduate Students, Celeste Kenworthy Jan 2022

Interaction With Augmented Reality Sandbox Does Not Produce Greater Gains In Topographic Map Skills For Undergraduate Students, Celeste Kenworthy

Honors Program: Senior Projects (Public)

The augmented reality (AR) sandbox allows students to interact with topographic maps in a 3D space. Being able to understand topographic maps is important to geologists and they are taught in many introductory geology courses. Recent research has focused on whether the AR sandbox can improve students’ topographic map skills. Previous studies have found that students who interact with the AR sandbox do not score significantly better on topographic map assessments (TMAs) than their peers. One proposed reason for this is the limited time students have to interact with the AR sandbox. This study sought to address this by creating …


Interspecific And Local Variation In Tern Chick Diets Across Nesting Colonies In The Gulf Of Maine, Keenan Yakola, Adrian Jordaan, Stephen Kress, Paula Shannon, Michelle D. Staudinger Nov 2021

Interspecific And Local Variation In Tern Chick Diets Across Nesting Colonies In The Gulf Of Maine, Keenan Yakola, Adrian Jordaan, Stephen Kress, Paula Shannon, Michelle D. Staudinger

United States Geological Survey: Staff Publications

The Gulf of Maine, USA is home to four colonial co-nesting tern species: Least Tern (Sternula antillarum), Common Tern (Sterna hirundo), Arctic Tern (Sterna paradisaea), and the federally endangered Roseate Tern (Sterna dougallii). Over three decades of visual observations of chick provisioning were compiled for a comparative dietary study in the region, including the first detailed descriptions of Least and Roseate Tern chick diets. Three prey groups comprised the majority of chick diets among tern species between 1986–2017: hake (Urophycis spp. or Enchelyopus cimbrius) 28–37% frequency of occurrence (FO), sand lance …


Exposure Of Predatory And Scavenging Birds To Anticoagulant Rodenticides In France: Exploration Of Data From French Surveillance Programs, Meg-Anne Moriceau, Sébastien Lefebvre, Isabelle Fourel, Etienne Benoit, Florence Buronfosse-Roque, Pascal Orabi, Barnett A. Rattner, Virginie Lattard Nov 2021

Exposure Of Predatory And Scavenging Birds To Anticoagulant Rodenticides In France: Exploration Of Data From French Surveillance Programs, Meg-Anne Moriceau, Sébastien Lefebvre, Isabelle Fourel, Etienne Benoit, Florence Buronfosse-Roque, Pascal Orabi, Barnett A. Rattner, Virginie Lattard

United States Geological Survey: Staff Publications

Wild raptors are widely used to assess exposure to different environmental contaminants, including anticoagulant rodenticides (ARs). ARs are used on a global scale for rodent control, and act by disruption of the vitamin K cycle that results in haemorrhage usually accompanied by death within days. Some ARs are highly persistent and bioaccumulative, which can cause significant exposure of non-target species.We characterized AR exposure in a heterogeneous sample of dead raptors collected over 12 years (2008–2019) in south-eastern France. Residue analysis of 156 liver samples through LC-MS/MS revealed that 50% (78/156) were positive for ARs, with 13.5% (21/156) having summed second-generation …


Recharge Assessment In The Context Of Expanding Agricultural Activity: Urucuia Aquifer System, Western State Of Bahia, Brazil, Glauco Z.S. Eger, Gerson C. Silva Junior, Eduardo A.G. Marques, Bernardo R.C. Leão, Diana G.T.B. Da Rocha, Troy E. Gilmore, Luís G.H. Do Amaral, Juremá A.O. Silva, Christopher Neale Oct 2021

Recharge Assessment In The Context Of Expanding Agricultural Activity: Urucuia Aquifer System, Western State Of Bahia, Brazil, Glauco Z.S. Eger, Gerson C. Silva Junior, Eduardo A.G. Marques, Bernardo R.C. Leão, Diana G.T.B. Da Rocha, Troy E. Gilmore, Luís G.H. Do Amaral, Juremá A.O. Silva, Christopher Neale

Conservation and Survey Division: Faculty and Staff Publications

Groundwater recharge rate estimation is crucial to sustainable development of aquifers in intensely pumped regions, such as the Urucuia Aquifer System (UAS). A sedimentary aquifer in Western Bahia, Brazil, that underlies one of the major agricultural areas of the country where there has been major growth of irrigated areas. This study seeks to evaluate the recharge component of the water budget in the UAS area, based on three complementary techniques. The double-ring infiltrometer test was used to evaluate surface infiltration capacity, an important control on recharge. Water level data from wells (2011–2019 period, 19 wells) in the Brazilian Geological Survey’s …


Geology And Hydrogeology Of Northeastern Nebraska: Geology, Water Management And Geological Hazards, Nebraska Geological Society Field Trip 2021, Robert F. Diffendal Jr., Sue Olafsen Lackey, Douglas R. Hallum Oct 2021

Geology And Hydrogeology Of Northeastern Nebraska: Geology, Water Management And Geological Hazards, Nebraska Geological Society Field Trip 2021, Robert F. Diffendal Jr., Sue Olafsen Lackey, Douglas R. Hallum

Conservation and Survey Division: Faculty and Staff Publications

The 2021 Nebraska Geological Society field trip will provide an overview of the geology and hydrogeology of northeast Nebraska, the groundwater quality and quantity issues unique to the region, water management issues and decision-making, and ongoing work relating to water quality and geologic (hydrostratigraphic) framework, along the lower Niobrara and Missouri rivers Between Spencer Dam and Homer Nebraska. This program will be comprised of an auto tour with multiple stops on Saturday October 16 through Monday October 18 as illustrated in Map 1. The tour will begin with an examination of the Spencer Dam site and several locations in and …


Integrated Geophysical Analysis Over Bathymetrists Seamounts And The Sierra Leone Rise, Alexa Fernandez Jul 2021

Integrated Geophysical Analysis Over Bathymetrists Seamounts And The Sierra Leone Rise, Alexa Fernandez

UCARE: Research Products

The Bathymetrists Seamounts (BSM) are located northeast of the Sierra Leone Rise in the Atlantic Ocean. The northern seamounts have a southwest to northeast trend which is contrary to the current eastward motion of the African tectonic plate where they reside. The geological history and crustal structures of these features are poorly understood. The goal of this study is to integrate multiple geophysical data to better understand the crustal architecture and tectonic history of the BSM.

The seismic refraction study from Jones et al. (2015) was used as the baseline for isostatic modeling. This dataset suggested the presence of magmatic …


Developing A Database Of Seismic Data Over The Cascadia Subduction Zone, Khawlh Al Farsi Jul 2021

Developing A Database Of Seismic Data Over The Cascadia Subduction Zone, Khawlh Al Farsi

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

An inevitable megathrust earthquake is expected in the Cascadia subduction zone that will affect the population of the coast of southwestern British Columbia and the northwest of the United States. In this active tectonic margin, the Juan de Fuca oceanic plate is subducting beneath the North American continental plate, causing unevenly distributed seismic activity. The major goal of this geophysical research project is to study the tectonic structures of the Cascadia subduction zone in order to comprehend the geology of the region and investigate the seismic hazards. The primary objective of this project is to develop a geophysical database of …


Distribution And Trends Of Endemic Hawaiian Waterbirds, Eben H. Paxton, Kevin Brinck, Adonia Henry, Afsheen Siddiqi, Rachel Rounds, Jennifer Chutz Mar 2021

Distribution And Trends Of Endemic Hawaiian Waterbirds, Eben H. Paxton, Kevin Brinck, Adonia Henry, Afsheen Siddiqi, Rachel Rounds, Jennifer Chutz

United States Geological Survey: Staff Publications

Four endemic species of wetland-dependent waterbirds occur on the main Hawaiian Islands, all of which have experienced sharp population declines and are listed as endangered species. Twice per year, state-wide surveys are conducted to count waterbirds, but these surveys are evaluated only infrequently. We used a state-space approach to evaluate long-term (1986–2016) and short-term (2006–2016) trends and current distribution and abundance of endemic Hawaiian waterbirds. The most numerous species was the Ae‘o, or Hawaiian Stilt (Himantopus mexicanus knudseni), with a 5-year estimated average abundance of 1,932 individuals, followed by ‘Alae Ke‘oke‘o, or Hawaiian Coot (Fulica alai), …


Rock Glen Wildlife Area: A Landscape History, Gerry Steinauer, Robert Diffendal Jr. Mar 2021

Rock Glen Wildlife Area: A Landscape History, Gerry Steinauer, Robert Diffendal Jr.

Robert F. Diffendal, Jr., Publications

Nestled in the hills of southern Jefferson County, Rock Glen Wildlife Management Area, as its name implies, is a rocky land shaped by ancient geological forces, among them, meandering tropical rivers and grinding glacial ice. Euro-American settlers in the region arrived to a picturesque scene: rolling hills cloaked in tallgrass prairie fingered by glens, narrow valleys and canyons, filled with sprawling bur oaks. Too rocky to plow, southern Jefferson County has survived as an island of prairie amidst a sea of cropland. Settlement was not kind to the land. Fire suppression allowed eastern red cedars and other trees to spread, …