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Articles 20761 - 20790 of 29947

Full-Text Articles in Geology

Bat Guano Minerals And Mineralization Processes In Chameau Cave, Eastern Morocco, Philippe Audra, Vasile Heresanu, Lionel Barriquand, Mohamed El Kadiri Boutchich, Stephane Jaillet, Edwige Pons-Branchu, Pavel Bosak, Hai Cheng, R Lawrence Edwards, Michel Renda Apr 2021

Bat Guano Minerals And Mineralization Processes In Chameau Cave, Eastern Morocco, Philippe Audra, Vasile Heresanu, Lionel Barriquand, Mohamed El Kadiri Boutchich, Stephane Jaillet, Edwige Pons-Branchu, Pavel Bosak, Hai Cheng, R Lawrence Edwards, Michel Renda

International Journal of Speleology

The decay of bat guano deposits in caves produces mineral accumulations, mainly phosphates and secondary sulfates. Chameau Cave, Eastern Morocco, is located in the semi-arid Bni Snassen Mountains. It is composed of semi-active and dry passages, and is featured by strong condensation-corrosion on the walls, presence of fluvial sediments, and old corroded flowstones. Due to forced and convective airflow, the cave is generally very dry, with some damp sites related to condensation. Samples collected on the surface of different passages and along two sediment profiles yielded minerals related to bat guano decay. On recent or fresh guano, precursor minerals correspond …

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The Role Of Hydrated Minerals And Space Weathering Products In The Bluing Of Carbonaceous Asteroids, David Trang, Michelle S. Thompson, Bet E. Clark, Hannah H. Kaplan, Xiao-Duan Zou, Jian-Yang Li, Salvatore M. Ferrone, Victoria E. Hamilton, Amy A. Simon, Dennis C. Reuter, Lindsay P. Keller, M. Antonietta Barucci, Humberto Campins, Cateline Lantz, Daniella N. Dellagiustina, Ronald-Louis Ballouz, Erica R. Jawin, Harold Connolly Jr., Kevin J. Walsh, Dante Lauretta Apr 2021

The Role Of Hydrated Minerals And Space Weathering Products In The Bluing Of Carbonaceous Asteroids, David Trang, Michelle S. Thompson, Bet E. Clark, Hannah H. Kaplan, Xiao-Duan Zou, Jian-Yang Li, Salvatore M. Ferrone, Victoria E. Hamilton, Amy A. Simon, Dennis C. Reuter, Lindsay P. Keller, M. Antonietta Barucci, Humberto Campins, Cateline Lantz, Daniella N. Dellagiustina, Ronald-Louis Ballouz, Erica R. Jawin, Harold Connolly Jr., Kevin J. Walsh, Dante Lauretta

School of Earth & Environment Departmental Research

The surfaces of airless bodies such as lunar and S-type asteroids typically become spectrally redder in visible to near-infrared reflectance with longer exposures to space weathering. However, some carbonaceous asteroids instead become spectrally bluer. Space weathering experiments on carbonaceous meteorites have provided some clues as to the space weathering products that could produce spectral bluing. We applied these experimental results to our Hapke radiative transfer model, with which we modeled spectral data from the OSIRIS-REx mission in order to determine whether these space weathering products—specifically, nanophase and microphase metallic iron, troilite, and magnetite—could explain the globally blue spectrum of the …

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Application Of The Global Srtm And Aw3d30 Digital Elevation Models To Mapping Folds At Cave Sites, Mark J. Abolins, Albert E. Ogden Apr 2021

Application Of The Global Srtm And Aw3d30 Digital Elevation Models To Mapping Folds At Cave Sites, Mark J. Abolins, Albert E. Ogden

International Journal of Speleology

A novel method to map and quantitatively describe very gentle folds (limb dip <5o) at cratonic cave sites was evaluated at Snail Shell and Nanna Caves, central Tennessee, USA. Elevations from the global SRTM digital terrain model (DTM) were assigned to points on late Ordovician geologic contacts, and the elevations of the points were used to interpolate 28 m cell size natural neighbor digital elevation models (DEM’s) of the contacts. The global Forest Canopy Height Dataset was subtracted from the global 28 m cell size AW3D30 digital surface model (DSM) to create a DTM, and that DTM was applied …

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Investigating The Hydrology Of The Western Greenland Ice Sheet: Spatiotemporal Variability And Implications On Ice-Dynamics, Jessica Z. Mejia Apr 2021

Investigating The Hydrology Of The Western Greenland Ice Sheet: Spatiotemporal Variability And Implications On Ice-Dynamics, Jessica Z. Mejia

USF Tampa Graduate Theses and Dissertations

Since the 1990's the Greenland Ice Sheet (GrIS) has been losing mass at an accelerating rate in response to climatic warming and is currently the largest terrestrial contributor to sea-level rise. While ice sheet models agree the GrIS will continue losing mass throughout the century, there are significant uncertainties associated with future sea-level rise contributions. Predicting the GrIS's response to future climate warming scenarios is limited by gaps in our understanding of the links between ice sheet hydrology and dynamics. Meltwater produced on the ice surface flows within supraglacial streams that deliver it to crevasses or moulins—vertical conduits extending from …

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Spatial Variations Of Upper Crustal Anisotropy Along The San Jacinto Fault Zone In Southern California: Constraints From Shear Wave Splitting Analysis, Enyuan Jiang, Kelly H. Liu, Yuan Gao, Xiaofei Fu, Stephen S. Gao Apr 2021

Spatial Variations Of Upper Crustal Anisotropy Along The San Jacinto Fault Zone In Southern California: Constraints From Shear Wave Splitting Analysis, Enyuan Jiang, Kelly H. Liu, Yuan Gao, Xiaofei Fu, Stephen S. Gao

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

To discern spatial and explore possible existence of temporal variations of upper crustal anisotropy in an ∼15 km section of the San Jacinto Fault Zone (SJFZ) that is composed of the Buck Ridge and Clark faults in southern California, we conduct a systematic shear wave splitting investigation using local S-wave data recorded by three broadband seismic stations located near the surface expression of the SJFZ. An automatic data selection and splitting measurement procedure is first applied, and the resulting splitting measurements are then manually screened to ensure reliability of the results. Strong spatial variations in crustal anisotropy are revealed by …

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Carbonatite Metasomatism And Water Systematics Of Peridotite Xenoliths From Lanzarote, Canaries, Sierra N. Patterson Apr 2021

Carbonatite Metasomatism And Water Systematics Of Peridotite Xenoliths From Lanzarote, Canaries, Sierra N. Patterson

Theses and Dissertations

Water in Earth’s mantle, present as structurally bound hydrogen in minerals, influences large scale processes like mantle deformation, plate tectonics, and melting. To better understand the processes controlling water concentrations in the Earth’s upper mantle, we analyzed hydrogen (calculated as ppm wt. H2O), major, and trace element concentrations in minerals from peridotite mantle xenoliths of Lanzarote, Canaries. The Canaries Islands are thought to be the surface expression of a deep-seated mantle plume erupting through the Atlantic Ocean lithosphere. Carbonatite magmas have erupted in the Canaries and previous studies have shown evidence for carbonatite metasomatism in Lanzarote peridotites. Thus, …

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Radiogenic Pb Enrichment Of Mississippi Valley-Type Metallic Ore Deposits, Southern Ozarks: Constraints Based On Geochemical Studies Of Source Rocks And Their Diagenetic History, Jonathan Chick, Sydney E. Mckim, Adriana Potra, Walter L. Manger, John R. Samuelsen Apr 2021

Radiogenic Pb Enrichment Of Mississippi Valley-Type Metallic Ore Deposits, Southern Ozarks: Constraints Based On Geochemical Studies Of Source Rocks And Their Diagenetic History, Jonathan Chick, Sydney E. Mckim, Adriana Potra, Walter L. Manger, John R. Samuelsen

Geosciences Faculty Publications and Presentations

Southern Ozark Mississippi Valley-type ores are enriched in radiogenic Pb, with isotopic signatures suggesting that metals were supplied by two end-member components. While the less radiogenic component appears to be derived from various shale and sandstone units, the source of the more radiogenic component has not yet been identified. Analyses of cherts from the Early Ordovician Cotter Dolomite and tripolitic chert from the Early Mississippian Boone Formation contain highly radiogenic Pb, with isotopic ratios comparable to those of ores. However, most samples have lower 208Pb/204Pb and 207Pb/204Pb for a given 206Pb/204Pb …

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Rutile As A Provenance Indicator For The Camerino Sandstone Of The Camerino Basin, Apennine Mountain Region, Italy, Wendy Bogil Apr 2021

Rutile As A Provenance Indicator For The Camerino Sandstone Of The Camerino Basin, Apennine Mountain Region, Italy, Wendy Bogil

Honors Capstones

No abstract provided.

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Investigation Of Hurricane Irma Deposits, Big Pine Key, Florida, Youzhu Wang Apr 2021

Investigation Of Hurricane Irma Deposits, Big Pine Key, Florida, Youzhu Wang

USF Tampa Graduate Theses and Dissertations

Few paleotempestological studies have focused on coastal sinkholes, a common feature in Florida, which can receive and preserve storm overwash sediments. The major goal of this research is to improve our understanding of the characteristic signatures of storm sediments in sinkholes thereby determining reliability of these environments as proxies for hurricanes. Hurricane Irma as a Category 5 storm provides an excellent case study for characterizing storm deposits in sinkholes on Big Pine Key. I cored at four sinkholes along a 350 m transect normal to the shoreline. Core sediments were characterized using physical description, short-lived radioisotope dating, sediment grain size …

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Radium At The Lost City And Mid-Cayman Rise Hydrothermal Fields, Jessica D. Frankle Apr 2021

Radium At The Lost City And Mid-Cayman Rise Hydrothermal Fields, Jessica D. Frankle

Theses and Dissertations

Fluid residence times of deep-sea hydrothermal circulation influence chemical cycling in the ocean. While fluid residence time estimates exist for many basalt-hosted systems, no estimates exist for serpentinite hosted systems that emit fluids with inherently different chemistry. We measured short- and long-lived radium (Ra) nuclides in fluids from two hydrothermal systems on the Mid-Cayman Rise to constrain their residence times: the Von Damm Vent Field, a mixed ultramafic-mafic system, and the Piccard Vent Field, a mafic, neovolcanic system. Von Damm fluids contain remarkably elevated 223Ra activities (half-life = 11.4 days), surpassing those from basalt-hosted hydrothermal systems by one to two …

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Monitoring Of Carbon Dioxide Injection In The Southeastern United States, Adil Murad Awad Alshammari Apr 2021

Monitoring Of Carbon Dioxide Injection In The Southeastern United States, Adil Murad Awad Alshammari

Theses and Dissertations

Over the past few decades, measured levels of atmospheric carbon dioxide have substantially increased. One way to limit the adverse impacts of increased carbon dioxide concentrations is to capture and store it inside Earth's subsurface, a process known as CO2 sequestration. This method's success is critically dependent on the ability to confine injected CO2 for up to thousands of years. Establishing effective maintenance of sealing systems of reservoirs is of importance to prevent CO2 leakage. Understanding the nature and rate of potential CO2 leakage related to this injection process is essential to evaluating seal effectiveness and ultimately mitigating global warming. …

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Geo-Spatial Modeling Of Carbon Sequestration Assessment In Date Palm, Abu Dhabi: An Integrated Approach Of Fieldwork, Remote Sensing, And Gis, Basam Saeed Dahy Apr 2021

Geo-Spatial Modeling Of Carbon Sequestration Assessment In Date Palm, Abu Dhabi: An Integrated Approach Of Fieldwork, Remote Sensing, And Gis, Basam Saeed Dahy

Dissertations

The United Arab Emirates (UAE) has undertaken huge efforts to green the desert and afforestation projects (planted mainly with date palms) hence, reducing its carbon footprint, which have never been accounted for, because of lack of implemented mechanisms and tools to assess the amount of biomass and carbon stock (CS) sequestered by plants in the country. The purpose of this dissertation is to implement a new approach towards assessing the carbon sequestered by date palm (DP) plantations in Abu Dhabi, in both their biomass compartment as well as the soils under beneath, using geospatial technologies (RS and GIS) assessed by …

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Reconstructing Surface Water Carbonate Ion Concentration Changes In The Eastern Equatorial Pacific Across Glacial Transitions, Lenzie Gail Ward Apr 2021

Reconstructing Surface Water Carbonate Ion Concentration Changes In The Eastern Equatorial Pacific Across Glacial Transitions, Lenzie Gail Ward

OES Theses and Dissertations

Today, the eastern equatorial Pacific (EEP) plays a critical role in the global CO2 budget as a major source of CO2 to the atmosphere, but recent studies suggest the region may shift to a sink for atmospheric CO2 under different climate states. Here, I focus on two transitional periods, the last deglaciation (25 kyr to present) and last glaciation (the Marine Isotope Stage (MIS) 5a-4 transition, 96 to 60 kyr), to investigate how the carbon system in the EEP responds to major climate changes. I measured B/Ca ratios in the planktic foraminifera Globigerina bulloides from core MV1014-17JC …

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Ancient Plant Dna Reveals High Arctic Greening During The Last Interglacial, Sarah E. Crump, Bianca Fréchette, Matthew Power, Sam Cutler, Gregory De Wet, Martha K. Raynolds, Jonathan H. Raberg, Jason P. Briner, Elizabeth K. Thomas, Julio Sepúlveda, Beth Shapiro, Michael Bunce, Gifford H. Miller Mar 2021

Ancient Plant Dna Reveals High Arctic Greening During The Last Interglacial, Sarah E. Crump, Bianca Fréchette, Matthew Power, Sam Cutler, Gregory De Wet, Martha K. Raynolds, Jonathan H. Raberg, Jason P. Briner, Elizabeth K. Thomas, Julio Sepúlveda, Beth Shapiro, Michael Bunce, Gifford H. Miller

Geosciences: Faculty Publications

Summer warming is driving a greening trend across the Arctic, with the potential for large-scale amplification of climate change due to vegetation-related feedbacks [Pearson et al., Nat. Clim. Chang. (3), 673–677 (2013)]. Because observational records are sparse and temporally limited, past episodes of Arctic warming can help elucidate the magnitude of vegetation response to temperature change. The Last Interglacial ([LIG], 129,000 to 116,000 y ago) was the most recent episode of Arctic warming on par with predicted 21st century temperature change [Otto-Bliesner et al., Philos. Trans. A Math. Phys. Eng. Sci. (371), 20130097 (2013) and Post et al., Sci. Adv. …

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Collaborative Research: Identifying Shallow Slow Slip Using Hematite Tectures And (U-Th)/He Thermochonometry Of Exhumed And Experimental Faults, Alexis Ault Mar 2021

Collaborative Research: Identifying Shallow Slow Slip Using Hematite Tectures And (U-Th)/He Thermochonometry Of Exhumed And Experimental Faults, Alexis Ault

Funded Research Records

No abstract provided.

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Hydro-Morphodynamics Of Sandy Coastal Embayments, Shamim Murshid Mar 2021

Hydro-Morphodynamics Of Sandy Coastal Embayments, Shamim Murshid

LSU Doctoral Dissertations

This dissertation investigates the hydro-morphodynamics of two major components of a sandy coastal environment: tidal inlets and embayment shorelines. In the first study, I focused on the evolution of inlet geometry by compiling and analyzing a database with 226 inlets worldwide with a special attention given to their width to depth ratio (or aspect ratio). I found that the aspect ratio has a weak dependency on tidal range and wave height, and they lie in different ranges for three types of tidal inlets: engineered, natural single-thread, and natural compound. I also developed a 2D hydro-morphodynamic model of an idealized barrier-inlet …

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Molecules To Mountains: A Multi-Proxy Investigation Into Ancient Climate And Topography Of The Pacific Northwest, Usa, Alexander Mclean, John Bershaw Mar 2021

Molecules To Mountains: A Multi-Proxy Investigation Into Ancient Climate And Topography Of The Pacific Northwest, Usa, Alexander Mclean, John Bershaw

Geology Faculty Publications and Presentations

We characterize the topographic evolution of the Pacific Northwest, United States, during the Cenozoic. New paleosol carbonate stable isotope (δ18O) results from central Oregon are presented, along with published proxy data, including fossil teeth, smectites, and carbonate concretions. We interpret a polygenetic history of Cascade Mountain topographic uplift along-strike, characterized by: 1) Steady uplift of the Washington Cascades through the Cenozoic due long-term arc rotation and shortening against a Canadian buttress, and 2) Uplift of the Oregon Cascades to similar-to-modern elevations by the late Oligocene, followed by topographic stagnation as extension developed into the Neogene. Since the Miocene, meteoric water …

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Impacts Of Experiential Learning On The Affective Domain: Gaining Insight Into How To Broaden Participation In The Geosciences, Meghan Lindsey Cook Mar 2021

Impacts Of Experiential Learning On The Affective Domain: Gaining Insight Into How To Broaden Participation In The Geosciences, Meghan Lindsey Cook

USF Tampa Graduate Theses and Dissertations

Experiential learning exercises, such as field trips, are a common pedagogical practice in geoscience curriculums. Their purpose is to facilitate the transfer of knowledge gained in a classroom or lab setting into a field setting, but can be considered a barrier for entry into the geosciences for those with disabilities, caregiver/employment responsibilities, or financial constraints. Educators have begun turned to other modalities, such as virtual field experiences (VFEs), to create a more inclusive environment in the geosciences. However, the validity of VFEs as a replacement for, or augmentation to traditional field trips has yet to be established. The cognitive domain …

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Investigating The Impact Of Meteoric Diagenesis On The Geochemistry Of Carbonate Eolianites, Eleuthera And Water Cay, The Bahamas, Graham S. Bonnot Mar 2021

Investigating The Impact Of Meteoric Diagenesis On The Geochemistry Of Carbonate Eolianites, Eleuthera And Water Cay, The Bahamas, Graham S. Bonnot

LSU Master's Theses

The geochemical signatures imparted in major, minor, and trace elements, combined with light isotopes, suggest promising applications regarding the stabilization of meteorically altered limestone eolianites. Previous high-resolution studies have indicated that elements associated with carbonate diagenesis such as Mg and Sr can be valuable proxies for salinity and aragonite dissolution, respectively. In addition to testing these proxies, the analyses of several temperature-, diagenetic-, bioactive-, and redox-sensitive elements were evaluated using laser ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS) to identify additional indicators during carbonate diagenesis. Two geochemical drivers of U were identified; (1) aragonite dissolution similar to Sr and (2) oxidation …

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Glacier Clear Ice Bands Indicate Englacial Channel Microbial Distribution, Gilda Varliero, Alexandra Holland, Gary L. A. Barker, Marian L. Yallop, Andrew G. Fountain, Alexandre M. Anesio Mar 2021

Glacier Clear Ice Bands Indicate Englacial Channel Microbial Distribution, Gilda Varliero, Alexandra Holland, Gary L. A. Barker, Marian L. Yallop, Andrew G. Fountain, Alexandre M. Anesio

Geology Faculty Publications and Presentations

Distant glacial areas are interconnected by a complex system of fractures and water channels which run in the glacier interior and characterize the englacial realm. Water can slowly freeze in these channels where the slow freezing excludes air bubbles giving the ice a clear aspect. This ice is uplifted to the surface ablation zone by glacial movements and can therefore be observed in the form of clear surface ice bands. We employed an indirect method to sample englacial water by coring these ice bands. We were able, for the first time, to compare microbial communities sampled from clear (i.e. frozen …

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Seismic Attenuation, Time Delays And Raypath Bending Of Teleseisms Beneath Uturuncu Volcano, Bolivia, Alexandra K. Farrell Mar 2021

Seismic Attenuation, Time Delays And Raypath Bending Of Teleseisms Beneath Uturuncu Volcano, Bolivia, Alexandra K. Farrell

USF Tampa Graduate Theses and Dissertations

A set of 14 teleseismic earthquakes was studied to determine how wave propagation was affected by a presumed magma body beneath Uturuncu volcano, Bolivia. Teleseisms are suitable for study because they are relatively long period, contain purely P waves, and have near-vertical incidence angles. The number of events is small but the events have good signal-to-noise ratios and very similar waveforms for each event so that reliable measurements could be made of arrival times and amplitudes. Attenuation of amplitudes occurs in a NW-SE trend beneath the volcano, 14 by 34 km (long axis NW-SE). Calculated values of the quality factor …

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The Importance Of The Study Of Igneous Rocks And Compositions To Constrain The Martian Planetary Evolution, Arya Udry University Of Nevada, Las Vegas, Justin Filiberto, Juliane Gross, Mariek Schmidt, Deanne Rogers, Libby Hausrath, Roger Wiens, Nina Lanza Mar 2021

The Importance Of The Study Of Igneous Rocks And Compositions To Constrain The Martian Planetary Evolution, Arya Udry University Of Nevada, Las Vegas, Justin Filiberto, Juliane Gross, Mariek Schmidt, Deanne Rogers, Libby Hausrath, Roger Wiens, Nina Lanza

Geoscience Faculty Research

This white paper summarizes the scientific importance of studying igneous compositions in meteorites, surface samples, and through orbital analyses to better constrain the geology of Mars as a whole and better understand the geological processes that have shaped Mars in the past and present.

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Bayesian Seismic Refraction Inversion For Critical Zone Science And Near-Surface Applications, Mong-Han Huang, Berit Hudson-Rasmussen, Scott Burdick, Vedran Lekić, Mariel D. Nelson, Kristen E. Fauria, Nicholas Schmerr Mar 2021

Bayesian Seismic Refraction Inversion For Critical Zone Science And Near-Surface Applications, Mong-Han Huang, Berit Hudson-Rasmussen, Scott Burdick, Vedran Lekić, Mariel D. Nelson, Kristen E. Fauria, Nicholas Schmerr

Environmental Science and Geology Faculty Research Publications

The critical zone (CZ) is the region of the Earth’s surface that extends from the bottom of the weathered bedrock to the tree canopy and is important because of its ability to store water and support ecosystems. A growing number of studies use active source shallow seismic refraction to explore and define the size and structure of the CZ across landscapes. However, measurement uncertainty and model resolution at depth are generally not evaluated, which makes the identification and interpretation of CZ features inconclusive. To reliably resolve seismic velocity with depth, we implement a Transdimensional Hierarchical Bayesian (THB) framework with reversible-jump …

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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), …

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Deriving Melt Rates At A Complex Ice Shelf Base Using In Situ Radar: Application To Totten Ice Shelf, Irena Vaňková, Sue Cook, J. Paul Winberry, Keith W. Nicholls, Benjamin K. Galton-Fenzi Mar 2021

Deriving Melt Rates At A Complex Ice Shelf Base Using In Situ Radar: Application To Totten Ice Shelf, Irena Vaňková, Sue Cook, J. Paul Winberry, Keith W. Nicholls, Benjamin K. Galton-Fenzi

Geological Sciences Faculty Scholarship

A phase-sensitive radar (ApRES) was deployed on Totten Ice Shelf to provide the first in situ basal melt estimate at this dynamic East Antarctic ice shelf. Observations of internal ice dynamics at tidal time scales showed that early arrivals from off-nadir reflectors obscure the true depth of the ice shelf base. Using the observed tidal deformation, the true base was found to lie at 1,910–1,950-m depth, at 350–400 m greater range than the first reflection from an ice-ocean interface. The robustness of the basal melt rate estimate was increased by using multiple basal reflections over the radar footprint, yielding a …

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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, …

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Seismic Anisotropy And Mantle Deformation Beneath The Central Sunda Plate, Wenkai Song, Youqiang Yu, Stephen S. Gao, Kelly H. Liu, Yifang Fu Mar 2021

Seismic Anisotropy And Mantle Deformation Beneath The Central Sunda Plate, Wenkai Song, Youqiang Yu, Stephen S. Gao, Kelly H. Liu, Yifang Fu

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The central Sunda plate, which forms the core of Southeast Asia, has been extensively studied based on analyses of data mainly from surface geological observations. In contrast, largely due to the limited coverage by seismic stations in the area, a number of key issues associated with mantle structure and dynamics remain enigmatic. These can possibly be constrained by investigating seismic azimuthal anisotropy in the upper mantle. Here we employ the shear wave splitting technique on three P-to-S converted phases from the core-mantle boundary (PKS, SKKS, and SKS) recorded by 11 stations to systematically explore the spatial variation of azimuthal anisotropy …

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Inferring The Subsurface Geometry And Strength Of Slow-Moving Landslides Using 3-D Velocity Measurements From The Nasa/Jpl Uavsar, Alexander L. Handwerger, Adam M. Booth, Mong-Han Huang, Eric J. Fielding Mar 2021

Inferring The Subsurface Geometry And Strength Of Slow-Moving Landslides Using 3-D Velocity Measurements From The Nasa/Jpl Uavsar, Alexander L. Handwerger, Adam M. Booth, Mong-Han Huang, Eric J. Fielding

Geology Faculty Publications and Presentations

The hazardous impact and erosive potential of slow‐moving landslides depends on landslide properties including velocity, size, and frequency of occurrence. However, constraints on size, in particular, subsurface geometry, are lacking because these types of landslides rarely fully evacuate material to create measurable hillslope scars. Here, we use pixel offset tracking with data from the NASA/JPL Uninhabited Aerial Vehicle Synthetic Aperture Radar to measure the three‐dimensional surface deformation of 134 slow‐moving landslides in the northern California Coast Ranges. We apply volume conservation to infer the actively deforming thickness, volume, geometric scaling, and frictional strength of each landslide. These landslides move at …

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Geology Study – Drilling Down At Red Trail Energy, University Of North Dakota. Energy And Environmental Research Center Mar 2021

Geology Study – Drilling Down At Red Trail Energy, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet about a 2019–2020 geophysical survey near Richardton, North Dakota. The survey investigated the area’s feasibility as a CO2 storage site, as part of the Red Trail Energy carbon capture and storage (CCS) research effort. Summarizes survey process and results. [This item is an outdated or superseded version and retained for historical purposes only. It may no longer reflect current information, policies, or practices.]

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Pacific Northwest Littoral Data, Curt D. Peterson, Kara E. P. Kingen Mar 2021

Pacific Northwest Littoral Data, Curt D. Peterson, Kara E. P. Kingen

Geology Faculty Datasets

This document contains five data tables in PDF file formats, that are used to characterize littoral subcell (beach, river mouth, and inner-shelf) conditions in the Pacific Northwest (PNW) region (Washington, Oregon, and Northern California). These data have been compiled from pre-existing data sets (see citations in Table notes and References, below) for the purposes of predicting possible beach erosion from potential future sea level rise (SLR), as introduced in Kingen (2018) and Peterson et al. (2019, 2020a,b). The five data tables include Heavy-mineral tracers (Table 1), Heavy-mineral data (normalized) (Table 2), Subcell beach profile settings (Table 3), Subcell beach profile …

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