Other Earth Sciences Commons^™

One Health In Action: Flea Control And Interpretative Education At Badlands National Park, David Eads, Lindsey Buehler, Anne Esbenshade, Jason Fly, Evan Miller, Holly Redmond, Emily Ritter, National Park Service, Sasha Wittmann, Paul Roghair, Eddie Childers

USGS Staff -- Published Research

No abstract provided.

Comparative Behavioral Ecotoxicology Of Inland Silverside Larvae Exposed To Pyrethroids Across A Salinity Gradient, Sara J. Hutton, Samreen Siddiqui, Emily I. Pedersen, Christopher Y. Markgraf, Amelie Segarra, Michelle L. Hladik, Richard E. Connon, Susanne M. Brander

USGS Staff -- Published Research

Pyrethroids, a class of commonly used insecticides, are frequently detected in aquatic environments, including estuaries. The influence that salinity has on organism physiology and the partitioning of hydrophobic chemicals, such as pyrethroids, has driven interest in how toxicity changes in saltwater compared to freshwater. Early life exposures in fish to pyrethroids cause toxicity at environmentally relevant concentrations, which can alter behavior. Behavior is a highly sensitive endpoint that influences overall organism fitness and can be used to detect toxicity of environmentally relevant concentrations of aquatic pollutants. Inland Silversides (Menidia beryllina), a commonly used euryhaline model fish species, were exposed from ...

Using Active Source Seismology To Image The Palos Verdes Fault Damage Zone As A Function Of Distance, Depth, And Geology, Travis Alongi, Emily E. Brodsky, Jared Kluesner, Daniel Brothers

USGS Staff -- Published Research

Fault damage zones provide a window into the non-elastic processes of an earthquake. Geological and seismic tomography methods have been unable to measure damage zones at depth with sufficient spatial sampling to evaluate the relative influence of depth, distance, and lithological variations. Here, we identify and analyze the damage zone of the Palos Verdes Fault offshore southern California using two 3D seismic reflection datasets. We apply a novel algorithm to identify discontinuities attributed to faults and fractures in large seismic volumes and examine the spatial distribution of fault damage in sedimentary rock surrounding the Palos Verdes Fault. Our results show ...

Level And Pattern Of Overstory Retention Shape The Abundance And Long-Term Dynamics Of Natural And Created Snags, Charles B. Halpern, Allison K. Rossman, Joan C. Hagar

USGS Staff -- Published Research

Standing dead trees, or snags, serve myriad functions in natural forests, but are often scarce in forests managed for timber production. Variable retention (VR), the retention of live and dead trees through harvest, has been adopted globally as a less intensive form of regeneration harvest. In this study, we explore how two key elements of VR systems — level (amount) and spatial pattern of live-tree retention — affect the carryover and post-harvest dynamics of natural and artificially created snags. We present nearly two decades of data from the DEMO Study, a regional-scale experiment in VR harvests of Douglas-fir-dominated forests in the Pacific ...

Airflow Dynamics In Wind Cave And Jewel Cave: How Do Barometric Caves Breathe?, Annika K. Gomell, Andreas Pflitsch

International Journal of Speleology

Recent research on air pressure propagation through barometric caves has revealed various speleoclimatological processes, which cause a more complex relationship between surface air pressure changes and resulting pressure gradients between cave and surface air than previously assumed. So far, however, studies on barometric cave airflow have only been based on surface air pressure measurements. Thus, this study investigates and compares airflow at the openings of Wind Cave and Jewel Cave – two major barometric cave systems in South Dakota, USA – as a response to surface air pressure changes and air pressure gradients. Based on high-resolution long-term air pressure measurements from the ...

Hydrogen Isotope Behavior During Rhyolite Glass Hydration Under Hydrothermal Conditions, Michael R. Hudak, Ilya N. Bindeman, James M. Watkins, Jacob B. Lowenstern

USGS Staff -- Published Research

The diffusion of molecular water (H₂O_m) from the environment into volcanic glass can hydrate the glass up to several wt% at low temperature over long timescales. During this process, the water imprints its hydrogen isotope composition (δD_H2O) to the glass (δD_gl) offset by a glass-H₂O fractionation factor (ΔD_gl-H2O = δD_gl – δD_H2O) which is approximately -33‰ at Earth surface temperatures. Glasses hydrate much more rapidly at higher, sub-magmatic temperatures as they interact with H₂O during eruption, transport, and emplacement. To aid in the interpretation of δD_gl in natural samples ...

Limits To Coseismic Landslides Triggered By Cascadia Subduction Zone Earthquakes, Alex R.R. Grant, William T. Struble, Sean R. Lahusen

USGS Staff -- Published Research

Landslides are a significant hazard and dominant feature throughout the landscape of the Pacific Northwest. However, the hazard and risk posed by coseismic landslides triggered by great Cascadia Subduction Zone (CSZ) earthquakes is highly uncertain due to a lack of local and global data. Despite a wealth of other geologic evidence for past earthquakes on the Cascadia Subduction Zone, no landslides have been definitively linked to such earthquakes, even in areas otherwise highly susceptible to failure. While shallow landslides may not leave a lasting topographical signature in the landscape, there are thousands of deep-seated landslides in Cascadia, and these deposits ...

Geomorphic And Paleoclimatic Implications Of Glacial Extent Records In The Sierra Nevada Del Cocuy, Colombia During Termination 1, Jordan Nickerson Herbert

Dartmouth College Master’s Theses

Reconstructions of past glacial extents using geomorphic mapping and cosmogenic dating provide an opportunity to infer past climates. A record of the past extents of tropical mountain glaciers is particularly useful because there are few other means to reconstruct past temperatures in high-altitude, low-latitude locations. The tropics play an outsized role in mediating global climate, yet there is a lack of understanding of how the tropics may have influenced past climate changes such as the most recent deglaciation (Termination 1, ~18–11.7 ka). Improving reconstructions of tropical mountain glaciers will aid in understanding the role of the tropics in ...

Self-Supervised Learning For Invariant Representations From Multi-Spectral And Sar Images, Pallavi Jain, Bianca Schoen Phelan, Robert Ross

Articles

Self-Supervised learning (SSL) has become the new state of the art in several domain classification and segmentation tasks. One popular category of SSL are distillation networks such as Bootstrap Your Own Latent (BYOL). This work proposes RS-BYOL, which builds on BYOL in the remote sensing (RS) domain where data are non-trivially different from natural RGB images. Since multi-spectral (MS) and synthetic aperture radar (SAR) sensors provide varied spectral and spatial resolution information, we utilise them as an implicit augmentation to learn invariant feature embeddings. In order to learn RS based invariant features with SSL, we trained RS-BYOL in two ways ...

Characteristics Of Wet Downburst Wind Events Using Mrms Radar Products, Eliana Globus

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

How Green Lakes State Park Got Its Name: The Optics And Appearance Of Fayetteville Green Lakes, Eric A. Schiff

Physics - All Scholarship

The extraordinary and variable appearance of the Fayetteville Green Lakes in the spring, summer, and fall has been the subject of journalistic and scientific attention for more than 150 years. This article addresses the subject in two sections for differing readerships. The first section is a description of the essential science for a general readership. The second section is an abstract of the science for technically knowledgeable readers. The layout of the article is designed for a folded paper flier suitable for distribution to visitors to the lakes.

The article describes the three key properties of the lakes’ waters that ...

Limited Rigor In Studies Of Raptor Mortality And Mitigation At Wind Power Facilities, Tara J. Conkling, Christopher J.W. Mcclure, Sandra Cuadros, Scott R. Loss, Todd E. Katzner

USGS Staff -- Published Research

Wind power is an expanding source of renewable energy. However, there are ecological challenges related to wind energy generation, including collisions of wildlife with turbines. Lack of rigor, and variation in study design, together limit efforts to understand the broad-scale effects of wind power infrastructure on wildlife populations. It is not clear, however, whether these types of limitations apply to groups of birds such as raptors that are particularly vulnerable to negative effects of wind energy. We reviewed 672 peer-reviewed publications, unpublished reports, and citations from 321 wind facilities in 12 countries to evaluate methods used to monitor and mitigate ...

Early Miocene Redwood Fossils From Inner Mongolia: Co2 Reconstructions And Paleoclimate Effects Of A Low Mongolian Plateau, Jia-Qi Liang, Qin Leng, Liang Xiao, Daianne F. Hofig, Dana L. Royer, Yi Ge Zhang, Hong Yang

Science and Technology Faculty Journal Articles

The early Miocene (~16–23 Ma) marks a critical transition in the Earth climate history from an Oligocene (~23–34 Ma) cooling trend towards the well-documented warm middle Miocene Climate Optimum at ~ 15 Ma. In eastern Asia, this transition links changes of key topographic features, such as the Tibetan plateau and the Mongolian plateau, and their impact on the reorganization of climate systems, such as the Eastern Asian summer monsoon. Yet the dynamics of the interplay among these factors remain poorly understood, precluding our understanding of future climate changes. Global temperatures during the early Miocene were warmer than the present ...

Geochemical Characterization Of The Bone Spring Formation, Delaware Basin, Using Chemostratigraphy And Integrated Petrophysics, David Tonner

Electronic Theses and Dissertations

The Delaware Basin forms part of West Texas's and New Mexico’s famous petroleum-generating Permian Basin. The Bone Spring Formation is a prolific hydrocarbon producer within this basin, creating one of the world’s richest oil shales. This formation has lithological sequences that are characterized by repeating carbonate and siliciclastic intervals of a third-order cycle which can largely be correlated to highstand and lowstand systems tracts, respectively. Lithological complexity and facies change are manifested by debris flows, turbidites, and slumps. In addition to glacio-eustasy, both tectonism and broader Milankovitch cycles have influenced the depositional history. Previous investigations have utilized ...

Investigation Of Dead Ocean Quahogs (Arctica Islandica) Shells On The Mid-Atlantic Bight Continental Shelf, Alyssa Leclaire

Master's Theses

Ocean quahogs, Arctica islandica, are a long-lived, widely dispersed, biomass dominate in the Mid-Atlantic; therefore, quahog shells are valuable resources for studying climate change over time. Recently, dead ocean quahog shells were discovered south and inshore of the present biogeographic range of this animal. The presence of ocean quahog shells outside the current range is presumably a consequence of past regressions and transgressions of the Cold Pool, the bottom-trapped, cool body of water that allows boreal animals to live at lower latitudes. Dead ocean quahog shells were collected offshore of the DelMarVa Peninsula then radiocarbon-dated, evaluated for taphonomic condition, and ...

Precambrian Molar-Tooth Structure: Unraveling The Diagenesis Of Ancient Carbonates, Agustin Kriscautzky

Doctoral Dissertations

Molar-tooth structure (MTS) is an enigmatic carbonate fabric that occurs mainly within Proterozoic carbonate host rocks. It is composed of two distinct features: cracks of various morphologies and crack-filling calcite microspar. Although the origins of MTS remain unknown, most previous investigation has focused on the formation of the cracks and mechanisms involved in the void space generation, with less emphasis on the intriguing carbonate fill. In this study I have investigated molar-tooth bearing carbonates from regions that span both paleogeography and geologic time. Analysis at the microscopic scale, including traditional petrography, cathodoluminescence petrography, scanning electron microscopy, and micrometer-scale geochemical analyses ...

Glaciochemical Investigations In Three Southern Hemisphere Mountain Sites, Mariusz Potocki

Electronic Theses and Dissertations

The research presented in this dissertation focuses on glaciochemical records of trace elements, major ions, and stable water isotopes from three mountain regions: the Antarctic Peninsula, the Central Chilean Andes, and South Georgia Island.

The first section reports a significant increase in U concentration over 27 years on Detroit Plateau, Antarctic Peninsula. U concentrations in the ice core increase by as much as 102 between the 1980s and 2000s, accompanied by increased variability in recent years. The U concentration increase coincides with expanded open pit mining in the Southern Hemisphere, most notably Australia. Since other land-source dust elements do not ...

Spatial Stream Modeling Of Louisiana Waterthrush (Parkesia Motacilla) Foraging Substrate And Aquatic Prey In A Watershed Undergoing Shale Gas Development, Mack W. Frantz, Petra B. Wood, Steven C. Latta

USGS Staff -- Published Research

We demonstrate the use of spatial stream network models (SSNMs) to explore relationships between a semiaquatic bioindicator songbird, Louisiana Waterthrush (Parkesia motacilla), and stream monitoring and benthic macroinvertebrate data in an area undergoing shale gas development. SSNMs allowed us to account for spatial autocorrelation inherent to these environmental data types and stream properties that traditional modeling approaches cannot capture to elucidate factors that affect waterthrush foraging locations. We monitored waterthrush along 58.1 km of 1st- and 2nd-order headwater stream tributaries (n = 14) in northwestern West Virginia over a two year period (2013–2014), sampled benthic macroinvertebrates in waterthrush territories ...

Complex Unicellular Microfossils From The 1.9 Ga Gunflint Chert, Canada, Ana L. González Flores

Electronic Thesis and Dissertation Repository

The presence of eukaryotic life during the early Paleoproterozoic has been a matter of debate because well-preserved fossils older than 1.8 Ga rarely exhibit eukaryotic cellular microstructures. In this study, microfossils from the 1.9 Ga Gunflint Chert were studied using the extended-focal-depth imaging technique, combined with scanning electron microscopy, resulting in recognition of three types of large (10–35 μm diameter) complex unicellular bodies (CUBs) and one type of “multicellular body” (< 50 μm diameter). The CUBs show the following eukaryotic cyst-like structures: (1) radially arranged internal strands similar to those in some acritarchs and dinoflagellates; (2) regularly spaced long tubular processes, stubby pustules, and/or robust podia on the cell surface; (3) reticulate cell-wall sculpturing such as pits, ridges, and scale-like ornaments; and (4) internal bodies that may represent membrane-bounded organelles. These morphological features provide strong evidence for the presence of protists in the late Paleoproterozoic.

Among the three types of CUBs from the Gunflint microbiota, a new species, Germinosphaera gunflinta sp. nov., was recognized. This species has the diagnostic characteristics of Germinosphaera ...

Oxygen Speciation In Potassium Silicate And Potassium Aluminosilicate Glasses: Insights From X-Ray Photoelectron Spectroscopy, Ryan Sawyer

Electronic Thesis and Dissertation Repository

In a geological context, glasses are useful analogues for silicate melts as they are more readily studied in the laboratory using a wide range of techniques that are impractical for molten liquids. Understanding the structure of binary silicate glasses can help us understand more about the magmatic processes that affect terrestrial planetary bodies.

Potassium silicate glasses ranging in composition from 10 mol% to 35 mol% K₂O were studied using X-ray Photoelectron Spectroscopy (XPS). From high resolution O 1s XPS spectra, Bridging Oxygen (BO) mole fractions were calculated and compared with those of previous ²⁹Si MAS NMR studies ...