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2017

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Articles 421 - 450 of 1124

Full-Text Articles in Earth Sciences

Rhyolite Petrogenesis At Tower Mountain Caldera, Or, Elizabeth Ann Brown Jun 2017

Rhyolite Petrogenesis At Tower Mountain Caldera, Or, Elizabeth Ann Brown

Dissertations and Theses

Tower Mountain Caldera is the main feature of an Oligocene volcanic field located in the Umatilla National Forest, eastern Oregon. It is perfectly suited to investigate models of rhyolite petrogenesis as all of the important rock components for evaluating generation models are present in a single location and thus are presumably related; basalts, intermediate igneous rocks (which consist of older plutons and younger volcanic rocks, which are ~coeval with rhyolites), metamorphic basement rocks of significant grade, and rhyolites of varying composition. The formation of the caldera produced the Dale Tuff, which comprises the intra-caldera and outflow facies. 40Ar/39 …


Characterizing Great Salt Lake Dust Relative Other Regional Dust Sources, Colin Hale, Carling Greg Jun 2017

Characterizing Great Salt Lake Dust Relative Other Regional Dust Sources, Colin Hale, Carling Greg

Journal of Undergraduate Research

Dust storms occur frequently along the Wasatch Front. These dust events may have negative effects on human health and agriculture. To help understand dust events along the Wasatch Front, this study focuses on analyzing dust deposition to better locate dust emission sources. Understanding the source of dust events is important. This is important because Great Salt Lake water levels are dropping exposing lakebed. This newly expose lakebed may result in increased frequency and intensity of dust events. To understand if this lakebed is affecting the Wasatch Front and acting as an emission source.


Divergence In Life History Traits Between Two Populations Of A Seed-Dimorphic Halophyte In Response To Soil Salinity, Fan Yang, Jerry M. Baskin, Carol C. Baskin, Xuejun Yang, Dechang Cao, Zhenying Huang Jun 2017

Divergence In Life History Traits Between Two Populations Of A Seed-Dimorphic Halophyte In Response To Soil Salinity, Fan Yang, Jerry M. Baskin, Carol C. Baskin, Xuejun Yang, Dechang Cao, Zhenying Huang

Biology Faculty Publications

Production of heteromorphic seeds is common in halophytes growing in arid environments with strong spatial and temporal heterogeneity. However, evidence for geographic variation (reflecting local adaptation) is almost nonexistent. Our primary aims were to compare the life history traits of two desert populations of this halophytic summer annual Suaeda corniculata subsp. mongolica and to investigate the phenotypic response of its plant and heteromorphic seeds to different levels of salt stress. Dimorphic seeds (F1) of the halophyte S. corniculata collected from two distant populations (F0) that differ in soil salinity were grown in a common environment under …


Oroville Dam Scale Model At The Uwrl Helps Test Repair Plans Before Construction, Utah Water Research Laboratory Jun 2017

Oroville Dam Scale Model At The Uwrl Helps Test Repair Plans Before Construction, Utah Water Research Laboratory

News

Engineers at the Utah Water Research Laboratory at Utah State University have constructed a 1:50 scale model of the Orovill Dam spillway. The model initally featured the terrain conditions that were formed following the damaging flow events in February, and later tested the designs for the reconstruction plans. Lead engineers Dr. Michael Johnson and Dr. Zachary Sharp worked with a team of 15 engineers and technicians to construct the approximately 100-foot-long by 60-foot-wide model in just 40 days.


Characterizing Benthic Habitats Using Multibeam Sonar And Towed Underwater Video In Two Marine Protected Areas On The West Florida Shelf, Usa, Jennifer L. Brizzolara Jun 2017

Characterizing Benthic Habitats Using Multibeam Sonar And Towed Underwater Video In Two Marine Protected Areas On The West Florida Shelf, Usa, Jennifer L. Brizzolara

USF Tampa Graduate Theses and Dissertations

This study investigates a way to characterize the geology and biology of the seafloor in two Marine Protected Areas on the West Florida Shelf. Characterization of benthic habitats needs to include sufficient detail to represent the complex and heterogeneous bottom types. Characterizations can be interpreted from multiple data sets and displayed as benthic habitat maps. Multibeam sonar bathymetry and backscatter provide full spatial data coverage, but interpretation of such data requires some form of ground truth (to characterize the habitat). Imagery from towed underwater video provides continuous transects of seafloor data, which provide a more efficient method than data from …


Can Facebook Aid Sustainability? An Investigation Of Empathy Expression Within The Humans Of New York Blog, Hannah Wheeler, Courtney Quinn Jun 2017

Can Facebook Aid Sustainability? An Investigation Of Empathy Expression Within The Humans Of New York Blog, Hannah Wheeler, Courtney Quinn

Earth and Environmental Sciences Publications

This qualitative study offers a novel exploration of the links between social media, virtual intergroup contact, and empathy by examining how empathy is expressed through interactions on a popular social media blog. Global leaders are encouraging individuals to engage in behaviors and support policies that provide basic social foundations. It is difficult to motivate people to undertake such actions. However, research shows that empathy intensifies motivation to help others. It can cause individuals to see the world from the perspective of stigmatized group members and increase positive feelings. Social media offers a new pathway for virtual intergroup contact, providing opportunities …


Integrated Approach For Sinkhole Evaluation And Evolution Prediction In The Central Ebro Basin (Ne Spain), Oscar Pueyo Anchuela, Andrés Pocoví Juan, Antonio M. Casas Sainz, Javier Gracia Abadias, Carlos L. Liesa Carrera Jun 2017

Integrated Approach For Sinkhole Evaluation And Evolution Prediction In The Central Ebro Basin (Ne Spain), Oscar Pueyo Anchuela, Andrés Pocoví Juan, Antonio M. Casas Sainz, Javier Gracia Abadias, Carlos L. Liesa Carrera

International Journal of Speleology

Evaluation of karst hazards benefits from the integration of different techniques, methodologies and approaches. Each one presents a different signature and is sensitive to certain indicators related to karst hazards. In some cases, detailed analysis permits the evaluation of representativeness either from isolated approaches or by means of integrated analyses. In this study, we present the evaluation of an area with high density of karstic collapses at different evolutionary stages through the integration of surficial, historical, geomorphological and geophysical data in order to finally define the evolutionary model for karst activity development. The obtained dataset permits to identify different steps …


Trace Element Analysis Of Quartz Grains In The Wah Wah Springs Tuff And Granodiorite Intrusion, Joel Barker, Dr. Eric Christiansen Jun 2017

Trace Element Analysis Of Quartz Grains In The Wah Wah Springs Tuff And Granodiorite Intrusion, Joel Barker, Dr. Eric Christiansen

Journal of Undergraduate Research

The Wah Wah Springs tuff and cogenetic granodiorite were part of the creation of the Indian Peak-Caliente Caldera Complex, which lies on the Nevada-Utah border (Skidmore, 2013). The complex formed during the middle Cenozoic (36-18 Ma) during an episode of explosive silicic activity (Best et al., 2013). Rollback of the subducting lithosphere likely caused the silicic activity, evidenced by the migration of magmatism southward (Best et al., 2013). The dehydration of the subducting oceanic lithosphere caused mafic magmas high in water to rise and fractionate in continental crust before eruption (Skidmore, 2013). Over twenty-four different ignimbrites have been found in …


Seeing The World Through New Eyes: Implementing Map-Based Mobile Apps In Field Trips And Research, Mariah Chambers, Ron Harris Jun 2017

Seeing The World Through New Eyes: Implementing Map-Based Mobile Apps In Field Trips And Research, Mariah Chambers, Ron Harris

Journal of Undergraduate Research

Mobile apps are a resource that can aid in field trip instruction and enhance students’ learning. Because the specific location of the field trip is often an important element in overall understanding, map-based learning materials can be used to integrate information with the place, providing context for the concepts that will be learned on the field trip. The purpose of this project was twofold. One purpose was to provide professors with information and instructions for using map-based mobile apps to prepare students for, and provide resources during, field trips and study abroad experiences. A second purpose was to implement the …


Analyzing Dam Feasibility In The Willamette River Watershed, Alexander Cameron Nagel Jun 2017

Analyzing Dam Feasibility In The Willamette River Watershed, Alexander Cameron Nagel

Dissertations and Theses

This study conducts a dam-scale cost versus benefit analysis in order to explore the feasibility of each the 13 U.S. Army Corps of Engineers (USACE) commissioned dams in Oregon’s Willamette River network. Constructed between 1941 and 1969, these structures function in collaboration to comprise the Willamette River Basin Reservoir System (WRBRS). The motivation for this project derives from a growing awareness of the biophysical impacts that dam structures can have on riparian habitats. This project compares each of the 13 dams being assessed, to prioritize their level of utility within the system. The study takes the metrics from the top …


Karst Development Of An Evaporitic System And Its Hydrogeological Implications Inferred From Gis-Based Analysis And Tracing Techniques, José M. Gil-Márquez, Juan A. Barberá, Matías Mudarra, Bartolomé Andreo, Jorge Prieto-Mera, Damián Sánchez, L. David Rizo-Decelis, Manuel Argamasilla, José M. Nieto, Beatríz De La Torre Jun 2017

Karst Development Of An Evaporitic System And Its Hydrogeological Implications Inferred From Gis-Based Analysis And Tracing Techniques, José M. Gil-Márquez, Juan A. Barberá, Matías Mudarra, Bartolomé Andreo, Jorge Prieto-Mera, Damián Sánchez, L. David Rizo-Decelis, Manuel Argamasilla, José M. Nieto, Beatríz De La Torre

International Journal of Speleology

The geomorphological characteristics and hydrogeological functioning of a geologically heterogeneous evaporitic karst plateau in Southern Spain were studied. Land surface information (LiDAR data) was used to analyze the shape and distribution of closed depressions. An artificial tracer test and monitoring of the natural responses of the main spring have allowed to infer the karstic development of the studied system. Three dyes were injected in selected swallow holes to trace the main groundwater flowpaths and to estimate the dimension of the conduit network. Discharge, electrical conductivity and temperature were monitored in the groundwater that drains the evaporitic plateau during an individual …


Comprehensive Silica Removal With Ferric Compounds For Industrial Wastewater Reuse, Ehren D. Baca Jun 2017

Comprehensive Silica Removal With Ferric Compounds For Industrial Wastewater Reuse, Ehren D. Baca

Civil Engineering ETDs

Cooling towers, integrated circuit (IC) manufacture and reverse osmosis (RO) generate copious amounts of wastewater high in colloidal and reactive silica inhibiting on-site or synergistic reuse. Silica present in cooling water can reach solubility limits via evaporation and form impervious scale on heat transfer surfaces that decreases efficiency. When water is treated by RO operating at high rejection, silica forms difficult-to-remove scale on the membrane feed side in the form of glassy patches and communities of aggregate particles, inhibiting aspirations for zero liquid discharge. Current methods for silica scale mitigation include abundant dosing with chemical antiscalents or complex operating schemes. …


Integrating Future Scenario-Based Crop Expansion And Crop Conditions To Map Switchgrass Biofuel Potential In Eastern Nebraska, Usa, Yingxin Gu, Bruce K. Wylie Jun 2017

Integrating Future Scenario-Based Crop Expansion And Crop Conditions To Map Switchgrass Biofuel Potential In Eastern Nebraska, Usa, Yingxin Gu, Bruce K. Wylie

United States Geological Survey: Staff Publications

Switchgrass (Panicum virgatum) has been evaluated as one potential source for cellulosic biofuel feedstocks. Planting switchgrass in marginal croplands and waterway buffers can reduce soil erosion, improve water quality, and improve regional ecosystem services (i.e. it serves as a potential carbon sink). In previous studies, we mapped high risk marginal croplands and highly erodible cropland buffers that are potentially suitable for switchgrass development, which would improve ecosystem services and minimally impact food production. In this study, we advance our previous study results and integrate future crop expansion information to develop a switchgrass biofuel potential ensemble map for current and future …


First Na Lidar Measurements Of Turbulence Heat Flux, Thermal Diffusivity, And Energy Dissipation Rate In The Mesopause Region, Yafang Guo, Alan Z. Liu, Chester S. Gardner Jun 2017

First Na Lidar Measurements Of Turbulence Heat Flux, Thermal Diffusivity, And Energy Dissipation Rate In The Mesopause Region, Yafang Guo, Alan Z. Liu, Chester S. Gardner

Publications

Turbulence is ubiquitous in the mesopause region, where the atmospheric stability is low and wave breaking is frequent. Measuring turbulence is challenging in this region and is traditionally done by rocket soundings and radars. In this work, we show for the first time that the modern Na wind/temperature lidar located at Andes Lidar Observatory in Cerro Pachón, Chile, is able to directly measure the turbulence perturbations in temperature and vertical wind between 85 and 100 km. Using 150 h of lidar observations, we derived the frequency (ω) and vertical wave number (m) spectra for both gravity …


Hydrogeological Flow In Gypsum Karst Areas: Some Examples From Northern Italy And Main Circulation Models, Bartolomeo Vigna, Ilenia M. D'Angeli, Adriano Fiorucci, Jo De Waele Jun 2017

Hydrogeological Flow In Gypsum Karst Areas: Some Examples From Northern Italy And Main Circulation Models, Bartolomeo Vigna, Ilenia M. D'Angeli, Adriano Fiorucci, Jo De Waele

International Journal of Speleology

A Messinian succession containing gypsum beds crops out in northern Italy, mainly in Piedmont and along the northern flank of the Apennine mountains in Emilia-Romagna. These gypsum bodies have been extensively quarried at the surface, in outcrops, and through underground quarries. In Emilia-Romagna these gypsum outcrops can be rather extensive, several km long and up to 1 km wide, while in Piedmont they are mostly covered by silty-marly deposits of Upper Messinian and Pliocene age and show only sparse and small outcrops. The underground quarrying of these evaporite bodies in Piedmont has allowed studying in detail their hydrogeology, and the …


The Place Toolkit: Exposing Geospatial Ready Digital Collections, Eleta Exline, Hannah Hamalainen, Michael Routhier, Val Harper, Place Project Group Jun 2017

The Place Toolkit: Exposing Geospatial Ready Digital Collections, Eleta Exline, Hannah Hamalainen, Michael Routhier, Val Harper, Place Project Group

PLACE Project

PLACE, the Position-based Library Archive Coordinate Explorer, is a University of New Hampshire geospatial data server and search interface that enables discovery of digital collections. Identifying geographic coordinates for “geospatial ready” digitized cultural heritage materials is key to the project.

Presented: Open Repositories 2017, Brisbane, Australia. June 27, 2017


Urban Agglomeration: An Evolving Concept Of An Emerging Phenomenon, Chuanglin Fang, Danlin Yu Jun 2017

Urban Agglomeration: An Evolving Concept Of An Emerging Phenomenon, Chuanglin Fang, Danlin Yu

Department of Earth and Environmental Studies Faculty Scholarship and Creative Works

Urban agglomeration is a highly developed spatial form of integrated cities. It occurs when the relationships among cities shift from mainly competition to both competition and cooperation. Cities are highly integrated within an urban agglomeration, which renders the agglomeration one of the most important carriers for global economic development. Studies on urban agglomerations have increased in recent decades. In the research community, a consensus with regard to what an urban agglomeration is, how an urban agglomeration is delineated in geographic space, what efficient models for urban agglomeration management are, etc. is not reached. The current review examines 32,231 urban agglomeration-related …


Umphlett Qci June 2017, Natalie Umphlett Jun 2017

Umphlett Qci June 2017, Natalie Umphlett

High Plains Regional Climate Center: Staff Publications

Highlights for the Basin

Temperature and Precipitation Anomalies

Snowpack and Streamflow

Historic Flooding in Missouri

Spring Conditions Impact Agriculture

3-Month Precipitation and Temperature Outlooks

U.S. Seasonal Drought Outlook


Aerodynamic Roughness Length Estimation With Lidar And Imaging Spectroscopy In A Shrub-Dominated Dryland, Aihua Li, Wenguang Zhao, Jessica J. Mitchell, Nancy F. Glenn, Matthew J. Germino, Joel B. Sankey, Richard G. Allen Jun 2017

Aerodynamic Roughness Length Estimation With Lidar And Imaging Spectroscopy In A Shrub-Dominated Dryland, Aihua Li, Wenguang Zhao, Jessica J. Mitchell, Nancy F. Glenn, Matthew J. Germino, Joel B. Sankey, Richard G. Allen

Geosciences Faculty Publications and Presentations

The aerodynamic roughness length (Z0m) serves an important role in the flux exchange between the land surface and atmosphere. In this study, airborne lidar (ALS), terrestrial lidar (TLS), and imaging spectroscopy data were integrated to develop and test two approaches to estimate Z0m over a shrub dominated dryland study area in south-central Idaho, USA. Sensitivity of the two parameterization methods to estimate Z0m was analyzed. The comparison of eddy covariance-derived Z0m and remote sensing-derived Z0m showed that the accuracy of the estimated Z0m heavily depends on the estimation model and the representation of …


Identifying Irrigated Areas In The Snake River Plain, Idaho: Evaluating Performance Across Composting Algorithms, Spectral Indices, And Sensors, Eric W. Chance, Kelly M. Cobourn, Valerie A. Thomas, Blaine C. Dawson, Alejandro N. Flores Jun 2017

Identifying Irrigated Areas In The Snake River Plain, Idaho: Evaluating Performance Across Composting Algorithms, Spectral Indices, And Sensors, Eric W. Chance, Kelly M. Cobourn, Valerie A. Thomas, Blaine C. Dawson, Alejandro N. Flores

Geosciences Faculty Publications and Presentations

There are pressing concerns about the interplay between agricultural productivity, water demand, and water availability in semi-arid to arid regions of the world. Currently, irrigated agriculture is the dominant water user in these regions and is estimated to consume approximately 80% of the world’s diverted freshwater resources. We develop an improved irrigated land-use mapping algorithm that uses the seasonal maximum value of a spectral index to distinguish between irrigated and non-irrigated parcels in Idaho’s Snake River Plain. We compare this approach to two alternative algorithms that differentiate between irrigated and non-irrigated parcels using spectral index values at a single date …


Cascadia Subduction Tremor Muted By Crustal Faults, Ray E. Wells, Richard J. Blakely, Aaron G. Wech, Patricia A. Mccrory, Andrew Michael Jun 2017

Cascadia Subduction Tremor Muted By Crustal Faults, Ray E. Wells, Richard J. Blakely, Aaron G. Wech, Patricia A. Mccrory, Andrew Michael

Geology Faculty Publications and Presentations

Deep, episodic slow slip on the Cascadia subduction megathrust of western North America is accompanied by low-frequency tremor in a zone of high fluid pressure between 30 and 40 km depth. Tremor density (tremor epicenters per square kilometer) varies along strike, and lower tremor density statistically correlates with upper plate faults that accommodate northward motion and rotation of forearc blocks. Upper plate earthquakes occur to 35 km depth beneath the faults. We suggest that the faults extend to the overpressured megathrust, where they provide fracture pathways for fluid escape into the upper plate. This locally reduces megathrust fluid pressure and …


Sedimentology And Taphonomy Of The Abydosaurus Mcintoshi Quarry, (Naturita Formation, Early Cretaceous, Latest Albian), Dinosaur National Monument, Utah, Aaron Daniel Holmes Jun 2017

Sedimentology And Taphonomy Of The Abydosaurus Mcintoshi Quarry, (Naturita Formation, Early Cretaceous, Latest Albian), Dinosaur National Monument, Utah, Aaron Daniel Holmes

Theses and Dissertations

The holotypic locality of the brachiosaurid titanosauriform sauropod, Abydosaurus mcintoshi, is quarry DNM-16, located in Dinosaur National Monument. The bones are preserved near the base of a heterolithic, trough cross stratified to planar bedded sandstone channel complex. The trough cross to planar bedded sandstones mark times of variable flow with times of high flow velocity based on bones whose upper surfaces were eroded before final burial. The abundance of mud with the dominant medium to fine sand, and poorly confined sandstone channels indicate the bones were transported and buried in medial to distal intermittent flows of a distributive fluvial …


Noncanonical Alternative Polyadenylation Contributes To Gene Regulation In Response To Hypoxia, Laura De Lorenzo, Reed Sorenson, Julia Bailey-Serres, Arthur G. Hunt Jun 2017

Noncanonical Alternative Polyadenylation Contributes To Gene Regulation In Response To Hypoxia, Laura De Lorenzo, Reed Sorenson, Julia Bailey-Serres, Arthur G. Hunt

Plant and Soil Sciences Faculty Publications

Stresses from various environmental challenges continually confront plants, and their responses are important for growth and survival. One molecular response to such challenges involves the alternative polyadenylation of mRNA. In plants, it is unclear how stress affects the production and fate of alternative mRNA isoforms. Using a genome-scale approach, we show that in Arabidopsis thaliana, hypoxia leads to increases in the number of mRNA isoforms with polyadenylated 3′ ends that map to 5′-untranslated regions (UTRs), introns, and protein-coding regions. RNAs with 3′ ends within protein-coding regions and introns were less stable than mRNAs that end at 3′-UTR poly(A) sites. …


Facies Architecture And Provenance Of A Boulder-Conglomerate Submarine Channel System, Panoche Formation, Great Valley Group: A Forearc Basin Response To Middle Cretaceous Tectonism In The California Convergent Margin, T. J. Greene, Kathleen D. Surpless Jun 2017

Facies Architecture And Provenance Of A Boulder-Conglomerate Submarine Channel System, Panoche Formation, Great Valley Group: A Forearc Basin Response To Middle Cretaceous Tectonism In The California Convergent Margin, T. J. Greene, Kathleen D. Surpless

Earth and Environmental Geosciences Faculty Research

Tectonic reorganization induced by a rapid increase in plate motion ­obliquity and rate beginning at ca. 100 Ma affected California’s Andean-style convergent margin, with concomitant changes in the accretionary prism of the Franciscan Complex, the Great Valley forearc basin, and the Sierran continental arc. Using facies analysis and a combined provenance approach, we suggest that this ca. 100 Ma tectonic signal is preserved in a Cenomanian (Upper Cretaceous) boulder-conglomerate outcrop along the San Luis Reservoir (SLR) in the southern Great Valley, which represents the thickest and coarsest deep-water deposit ever described in the Great Valley Group (GVG). We document a …


Recirculation Over Complex Terrain, Eric Kutter, Chuixiang Yi, George Hendrey, Heping Liu, Timothy Eaton, Wenge Ni-Meister Jun 2017

Recirculation Over Complex Terrain, Eric Kutter, Chuixiang Yi, George Hendrey, Heping Liu, Timothy Eaton, Wenge Ni-Meister

Publications and Research

This study generated eddy covariance data to investigate atmospheric dynamics leeward of a small, forested hillside in upstate New York. The causes and effects of recirculation eddies were examined to support the larger goal of improving measurement of the exchange of energy, moisture, and trace gases between the terrestrial biosphere and the atmosphere over complex terrain. Sensors operated at five different altitudes on two separate towers—one at the top of the hill and one down the slope to the east—for approximately 8 weeks in the spring of 2013. During the experiment, the vertical potential temperature gradient was found to be …


Global Land Carbon Sink Response To Temperature And Precipitation Varies With Enso Phase, Yuanyuan Fang, Anna M. Michalak, Christopher R. Schwalm, Deborah N. Huntzinger, Joseph A. Berry, Philippe Ciais, Shilong Piao, Benjamin Poulter, Joshua B. Fisher, Robert B. Cook, Daniel Hayes, Maoyi Huang, Akihiko Ito, Atul Jain, Huimin Lei, Chaoqun Lu, Jiafu Mao, Nicholas C. Parazoo, Shushi Peng, Daniel M. Ricciuto, Xiaoying Shi, Bo Tao, Hanqin Tian, Weile Wang, Yaxing Wei, Jia Yang Jun 2017

Global Land Carbon Sink Response To Temperature And Precipitation Varies With Enso Phase, Yuanyuan Fang, Anna M. Michalak, Christopher R. Schwalm, Deborah N. Huntzinger, Joseph A. Berry, Philippe Ciais, Shilong Piao, Benjamin Poulter, Joshua B. Fisher, Robert B. Cook, Daniel Hayes, Maoyi Huang, Akihiko Ito, Atul Jain, Huimin Lei, Chaoqun Lu, Jiafu Mao, Nicholas C. Parazoo, Shushi Peng, Daniel M. Ricciuto, Xiaoying Shi, Bo Tao, Hanqin Tian, Weile Wang, Yaxing Wei, Jia Yang

Plant and Soil Sciences Faculty Publications

Climate variability associated with the El Niño-Southern Oscillation (ENSO) and its consequent impacts on land carbon sink interannual variability have been used as a basis for investigating carbon cycle responses to climate variability more broadly, and to inform the sensitivity of the tropical carbon budget to climate change. Past studies have presented opposing views about whether temperature or precipitation is the primary factor driving the response of the land carbon sink to ENSO. Here, we show that the dominant driver varies with ENSO phase. Whereas tropical temperature explains sink dynamics following El Niño conditions (r TG,P = 0.59, p …


Interpretive Geologic Cross Sections Across Lower Platte North Natural Resources District, Nebraska (Ccs-20), Dana Divine Jun 2017

Interpretive Geologic Cross Sections Across Lower Platte North Natural Resources District, Nebraska (Ccs-20), Dana Divine

Conservation and Survey Division: Faculty and Staff Publications

No abstract provided.


Modeling The Population Effects Of Hypoxia On Atlantic Croaker (Micropogonias Undulatus) In The Northwestern Gulf Of Mexico: Part 2—Realistic Hypoxia And Eutrophication, Kenneth A. Rose, Sean Creekmore, Dubravko Justić, Peter Thomas, J. Kevin Craig, Rachael Miller Neilan, Lixia Wang, Md Saydur Rahman, David Kidwell Jun 2017

Modeling The Population Effects Of Hypoxia On Atlantic Croaker (Micropogonias Undulatus) In The Northwestern Gulf Of Mexico: Part 2—Realistic Hypoxia And Eutrophication, Kenneth A. Rose, Sean Creekmore, Dubravko Justić, Peter Thomas, J. Kevin Craig, Rachael Miller Neilan, Lixia Wang, Md Saydur Rahman, David Kidwell

School of Earth, Environmental, & Marine Sciences Faculty Publications

Quantifying the population-level effects of hypoxia on coastal fish species has been challenging. In the companion paper (part 1), we described an individual-based population model (IBM) for Atlantic croaker in the northwestern Gulf of Mexico (NWGOM) designed to quantify the long-term population responses to low dissolved oxygen (DO) concentrations during the summer. Here in part 2, we replace the idealized hypoxia conditions with realistic DO concentrations generated from a 3-dimensional water quality model. Three years were used and randomly arranged into a time series based on the historical occurrence of mild, intermediate, and severe hypoxia year types.We also used another …


Receiver Function And Gravity Constraints On Crustal Structure And Vertical Movements Of The Upper Mississippi Embayment And Ozark Uplift, Lin Liu, Stephen S. Gao, Kelly H. Liu, Kevin Lee Mickus Jun 2017

Receiver Function And Gravity Constraints On Crustal Structure And Vertical Movements Of The Upper Mississippi Embayment And Ozark Uplift, Lin Liu, Stephen S. Gao, Kelly H. Liu, Kevin Lee Mickus

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The Upper Mississippi Embayment (UME), where the seismically active New Madrid Seismic Zone resides, experienced two phases of subsidence commencing in the Late Precambrian and Cretaceous, respectively. To provide new constraints on models proposed for the mechanisms responsible for the subsidence, we computed and stacked P-to-S receiver functions recorded by 49 USArray and other seismic stations located in the UME and the adjacent Ozark Uplift and modeled Bouguer gravity anomaly data. The inferred thickness, density, and Vp/Vs of the upper and lower crustal layers suggest that the UME is characterized by a mafic and high-density upper crustal …


Formation Of Rapakivi Feldspars In The Deer Isle Granite Complex, Coastal Maine: In Situ Lead Isotope And Trace Element Analysis, William Desmond Obrien Jun 2017

Formation Of Rapakivi Feldspars In The Deer Isle Granite Complex, Coastal Maine: In Situ Lead Isotope And Trace Element Analysis, William Desmond Obrien

Theses and Dissertations

Rapakivi and alkali feldspar phenocrysts from the Deer Isle Granite Complex were investigated using in situ trace element and Pb isotope geochemistry to see if magma mixing or isothermal decompression was responsible for their formation. Pb isotope and trace element profiles, along with CL imagery of quartz phenocrysts, indicate compositional changes in the magma chamber occurred during rapakivi and alkali feldspar growth. Repeated episodes of magma mixing/replenishment by relatively isotopically primitive and LREE enriched magmas (along with hybridized variations with the host magma) created localized disequilibration. Alkali feldspar phenocrysts proximal to these zones of thermal perturbation were first resorbed and …