Open Access. Powered by Scholars. Published by Universities.®

Other Earth Sciences Commons™

Open Access. Powered by Scholars. Published by Universities.®

2021

Discipline
Institution
Keyword
Publication
Publication Type

Articles 61 - 68 of 68

Full-Text Articles in Other Earth Sciences

Terrestrial Ecological Risk Analysis Via Dietary Exposure At Uranium Mine Sites In The Grand Canyon Watershed (Arizona, Usa), Jo Ellen Hinck, Danielle Cleveland, Bradley E. Sample Jan 2021

Terrestrial Ecological Risk Analysis Via Dietary Exposure At Uranium Mine Sites In The Grand Canyon Watershed (Arizona, Usa), Jo Ellen Hinck, Danielle Cleveland, Bradley E. Sample

United States Geological Survey: Staff Publications

The U.S. Department of the Interior recently included uranium (U) on a list of mineral commodities that are considered critical to economic and national security. The uses of U for commercial and residential energy production, defense applications, medical device technologies, and energy generation for space vehicles and satellites are known, but the environmental impacts of uranium extraction are not always well quantified. We conducted a screening-level ecological risk analysis based on exposure to miningrelated elements via diets and incidental soil ingestion for terrestrial biota to provide context to chemical characterization and exposures at breccia pipe U mines in northern Arizona. …


Metabarcoding Assays For The Detection Of Freshwater Mussels (Unionida) With Environmental Dna, Katy E. Klymus, Catherine A. Richter, Nathan Thompson, Jo Ellen Hinck, Jess W. Jones Jan 2021

Metabarcoding Assays For The Detection Of Freshwater Mussels (Unionida) With Environmental Dna, Katy E. Klymus, Catherine A. Richter, Nathan Thompson, Jo Ellen Hinck, Jess W. Jones

United States Geological Survey: Staff Publications

Freshwater mussels of the order Unionida are a widely distributed taxon that are important in maintaining freshwater ecosystems and are also highly imperiled throughout the world. Monitoring of mussel populations with environmental DNA (eDNA) is an attractive alternative to traditional methods because it is noninvasive and requires less labor and taxonomic knowledge from field personnel. We developed eDNA metabarcoding assays specific to freshwater mussels and tested them at six sites in the Clinch River, located in the southeastern United States. Our objective was to determine the utility of eDNA metabarcoding for future monitoring of mussel populations and restoration efforts in …


The Marine Terraces Of Santa Cruz Island, California: Implications For Glacial Isostatic Adjustment Models Of Last-Interglacial Sea-Level History, Daniel R. Muhs, R. Randall Schumann, Lindsey T. Groves, Kathleen R. Simmons, Christopher R. Florian Jan 2021

The Marine Terraces Of Santa Cruz Island, California: Implications For Glacial Isostatic Adjustment Models Of Last-Interglacial Sea-Level History, Daniel R. Muhs, R. Randall Schumann, Lindsey T. Groves, Kathleen R. Simmons, Christopher R. Florian

United States Geological Survey: Staff Publications

Glacial isostatic adjustment (GIA) models hypothesize that along coastal California, last interglacial (LIG, broadly from ~130 to ~115 ka) sea level could have been as high as +11 m to +13 m, relative to present, substantially higher than the commonly estimated elevation of +6 m. Areas with low uplift rates can test whether such models are valid. Marine terraces on Santa Cruz Island have previously been reported to occur at low (<10 m) elevations, but ages of many such localities are not known. Using lidar imagery as a base, marine terraces on Santa Cruz Island were newly mapped, elevations were measured, fossils were collected for U-series dating (corals), strontium isotope compositions and amino acid geochronology (mollusks), and paleozoogeography (all taxa). Sr isotope compositions of mollusks from the highest of three marine terraces give ages of ~2.5 Ma to 1.9 Ma, along with Pliocene ages, fromshells interpreted to be reworked. U-series ages of corals fromthewestern part of the island indicate that low-elevation terraces north of the Santa Cruz Island fault correlate to the LIG. Where corals are lacking, amino acid ratios and faunal aspects support terrace correlation to the LIG high stand of sea. Elevations of most terrace localities north of the east-west trending Santa Cruz Island fault, in both thewestern and eastern parts of the island, range from5.75mto 8mabove sea level, well belowthe modeled paleo-sealevel range. Subsidence is ruled out as a mechanism for explaining the lower-than-modeled elevations, because higher-elevation terraces are present alongmuch of the Santa Cruz Island coast north of the fault, indicating longterm tectonic uplift. The low elevations of the LIG terrace fragments are, however, consistent with a low rate of uplift derived from the higher, ~2.5–1.9 Ma terrace. A number of other localities on the Pacific Coast, also dated to the LIG, have marine terrace elevations below the modeled level. GIA models may have overestimated last interglacial sea level by a substantial amount and need to be revised if used for forecasts for future sea-level rise.


Long Term Nutrient And Chlorophyll A Dynamics Across Long Island Sound And Impacts On Dissolved Oxygen Conditions Within The Western Sound (1991-2019), Sherry Perreira Jan 2021

Long Term Nutrient And Chlorophyll A Dynamics Across Long Island Sound And Impacts On Dissolved Oxygen Conditions Within The Western Sound (1991-2019), Sherry Perreira

Dissertations and Theses

Nitrogen overload, eutrophication, and hypoxia have been challenging and persistent water quality problems in Long Island Sound (LIS) over the past decades with major impacts on commercial industries, ecology, and recreational activities in the region. Recognizing these problems, the EPA enforced three phases of the Clean Water Act (CWA) to reduce nitrogen loads in an effort to improve this important estuary. This study examines how nitrogen (NH3, NOx & TDN), chlorophyll a (CHLA), and dissolved oxygen (DO) concentrations changed in LIS over the past 30 years, in response to water quality regulations as well as changes in …


Advancement Of Full-Vector Variable-Temperature Magnetometry For Rock-Magnetic And Paleointensity Applications, Leonid Surovitskii Jan 2021

Advancement Of Full-Vector Variable-Temperature Magnetometry For Rock-Magnetic And Paleointensity Applications, Leonid Surovitskii

Dissertations, Master's Theses and Master's Reports

Data on the variation of the direction and strength of Earth’s ancient magnetic field (absolute paleointensity) provide crucial information into the mechanisms of the geodynamo and the Earth’s thermal history. However, the use of conventional methods and instrumentation for absolute paleointensity determination has been hampered by physicochemical alteration of the samples caused by multiple high-temperature cycles and long experiment durations. The reliability and efficiency of the measurement process can be improved by the measurement of the full remanent magnetization vector simultaneously with the temperature cycling of a sample. Such as approach can also substantially expand the scope of materials available …


A "Warm" Or "Cold" Early Mars: Evidence From Valley Networks, Xuezhi Cang Jan 2021

A "Warm" Or "Cold" Early Mars: Evidence From Valley Networks, Xuezhi Cang

Graduate Research Theses & Dissertations

Although Mars is cold and dry today, many lines of evidence suggest that ancient Mars had large amount of water and surface fluvial processes. However, climate modelers have encountered difficulties in modeling such early warm and wet conditions with an above freezing temperature, mainly due to the Martian orbit being further away from the Sun and the faintness of the young Sun. The main purpose of this dissertation is to test the ancient Martian climate hypotheses by investigating the spatial pattern of valley network (VN) properties that can survive post-formational modification (i.e., the robust characteristics) and by analogizing the Earth …


Estimating The Azimuthal Mode Structure Of Ultra Low Frequency Waves And Its Effects On The Radial Diffusion Of Radiation Belt Electrons, Mohammad Barani Jan 2021

Estimating The Azimuthal Mode Structure Of Ultra Low Frequency Waves And Its Effects On The Radial Diffusion Of Radiation Belt Electrons, Mohammad Barani

Graduate Theses, Dissertations, and Problem Reports (ETD)

Characterizing the azimuthal mode number �� of Ultra Low Frequency (ULF) waves is critical to quantifying the radial diffusion of radiation belt electrons. A Wavelet cross-spectral technique is applied to the compressional ULF waves observed by multiple pairs of GOES and MMS satellites to estimate the mode structure of ULF waves. A more realistic distribution of mode numbers is achieved by inclusion of the modes corresponding to different wave propagation directions as well as at �� higher than fundamental mode number. For the event study of a geomagnetic storm using GOES data, ULF wave power is found to dominate at …


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

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

Graduate Theses, Dissertations, and Problem Reports (ETD)

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