Controls on organic matter distributions in Eocene Lake Uinta, Utah and Colorado
Ronald C. Johnson, Tracey J. Mercier, Justin E. Birdwell
2019, Mountain Geologist (55) 177-216
The Green River Formation deposited in Eocene Lake Uinta in the Uinta and Piceance Basins, Utah and Colorado, contains the largest oil shale resource in the world with an estimated 1.53 trillion barrels of oil in-place in the Piceance Basin and 1.32 trillion barrels in the Uinta Basin. The Douglas...
Clarifying regional hydrologic controls of the Marañón River, Peru through rapid assessment to inform system-wide basin planning approaches
Alice F. Hill, Robert Stallard, Karl Rittger
2019, Elementa: Science of the anthropocene (6)
We use remote sensing to enhance the interpretation of the first baseline dataset of hydrologic, isotopic and hydrochemical variables spanning 620 km of the upper Marañón River, in Andean Peru, from the steep alpine canyons to the lower lying jungle. Remote, data-scarce river systems are under increased hydropower...
Controls of the spatial variability of denitrification potential in nontidal floodplains of the Chesapeake Bay watershed, USA
Alicia R. Korol, Gregory E. Noe, Changwoo Ahn
2019, Geoderma (338) 14-29
Identifying floodplains with high rates of denitrification will help prioritize restoration projects for the removal of nitrogen. Currently, relationships of denitrification with hydrogeomorphic, physiographic, and climate (i.e., largescale) characteristics of floodplains are relatively unknown, even though these characteristics have datasets (e.g., geographic mapping tools) that are publicly available (or soon-to-become) that could be used to understand denitrification...
Comparison of attraction, entrance and passage of downstream migrant American eels (Anguilla rostrata) through airlift and siphon deep entrance bypass systems
Nicola Baker, Alexander Haro, Barnaby J. Watten, John Noreika, Jonathan D. Bolland
2019, Ecological Engineering (126) 74-82
Downstream migrating anguillid eels face many barriers including turbines and pumps at impoundments for water abstraction, power generation and water level control, when attempting to exit the freshwater catchment to reach spawning grounds. Multiple eel species worldwide are facing different levels of endangerment and alleviating the...
Responses of biological soil crusts to rehabilitation strategies
Taylor Chock, Anita J. Antoninka, Akasha M. Faist, Matthew A. Bowker, Jayne Belnap, Nichole N. Barger
2019, Journal of Arid Environments (163) 77-85
Biological soil crusts (biocrusts) are common to dryland ecosystems and can influence a broad suite of soil ecological functions including stability and surface hydrology. Due to long recovery times following disturbance, there is a clear need for rehabilitation strategies to enhance the recovery of biocrust communities. Essential to biocrust recovery...
Measuring carbon and nitrogen bioassimilation, burial, and denitrification contributions of oyster reefs in Gulf coast estuaries
P. Westbrook, L. Heffner, Megan K. La Peyre
2019, Marine Biology (166)
The eastern oyster (Crassostrea virginica) and the reefs they create provide significant ecosystem services. This study measured their possible role in nutrient mitigation through bioassimilation, burial, and oyster-mediated sediment denitrification in near-shore shallow water (< 1 m water depth) and deep-water (> 1 m water depth) oyster reefs in Louisiana. Nitrogen (N) and carbon...
Radium accumulation in carbonate river sediments at oil and gas produced water discharges: Implications for beneficial use as disposal management
Bonnie McDevitt, Molly McLaughlin, Charles A. Cravotta III, Moses A Ajemigbitse, Katherine J. Van Sice, Jens Blotevogel, Thomas Borch, Nathaniel R. Warner
2019, Environmental Science (21) 324-338
In the western U.S., produced water from oil and gas wells discharged to surface water augments downstream supplies used for irrigation and livestock watering. Here we investigate six permitted discharges on three neighboring tributary systems in Wyoming. During 2013-16, we evaluated radium activities of the permitted discharges and the...
Chesapeake Bay impact structure—Development of "brim" sedimentation in a multilayered marine target
Henning Dypvik, Gregory Gohn, Lucy Edwards, J. Wright Horton, Jr., David Powars, Ronald Litwin
2019, Book chapter, Chesapeake Bay impact structure—Development of brim sedimentation in a multilayered marine target
The late Eocene Chesapeake Bay impact structure was formed in a multilayered target of seawater underlain sequentially by a sediment layer and a rock layer in a continental-shelf environment. Impact effects in the “brim” (annular trough) surrounding and adjacent to the transient crater, between the transient crater rim and the...
Modelling effects of invasive species and drought on crayfish extinction risk and population dynamics
Allyson N. Yarra, Daniel D. Magoulick
2019, Aquatic Conservation: Marine and Freshwater Ecosystems (29) 1-11
Hydrological alteration, which may be exacerbated by climate change, is known to facilitate aquatic species invasion. Altered hydrology, invasive species, and the additive effects of these stressors pose a threat to aquatic biodiversity.Understanding extinction risk in the context of these stressors is crucial for prioritizing conservation efforts. As case...
Optimal spatial allocation of control effort to manage invasives in the face of imperfect detection and misclassification
Mathieu Bonneau, Julien Martin, Nathalie Peyrard, LeRoy Rodgers, Christina M. Romagosa, Fred A. Johnson
2019, Ecological Modelling (392) 108-116
Imperfect detection and misclassification errors are often ignored in the context of invasive species management. Here we present an approach that combines spatially explicit models and an optimization technique to design optimal search and destroy strategies based on noisy monitoring observations. We focus on two invasive plants, melaleuca (Melaleuca quinquenervia)...
C–O stable isotope geochemistry and 40Ar/39Ar geochronology of the Bear Lodge carbonatite stockwork, Wyoming, USA
Allen K. Andersen, Peter B. Larson, Michael A. Cosca
2019, LITHOS (324-324) 640-660
The carbonatite dike swarm and vein stockwork at the center of the Paleogene Bear Lodge alkaline complex (BLAC), Wyoming, USA, is host to diverse REE mineral assemblages that are largely a result of subsolidus modification and REE redistribution. Pseudomorphic replacement of primary burbankite by an assemblage of ancylite, strontianite, and barite is the result of interaction with late-stage hydrothermal fluids that...
Overview of spirit microscopic imager results
Kenneth E. Herkenhoff, Steve W Squyres, Raymond E. Arvidson, Shoshanna B Cole, Rob Sullivan, Aileen Yingst, Nathalie Cabrol, Ella Lee, Janet Richie, Robert M. Sucharski, Fred J. Calef, James F. Bell III, Mary Chapman, Paul Geissler, Lauren A. Edgar, Brenda Franklin, Joel A. Hurowitz, Elsa Jensen, Jeffrey R. Johnson, Randolph L. Kirk, Peter Lanagan, Kevin Mullins, Craig Leff, Justin Maki, Bonnie L. Redding, Melissa Rice, Michael H. Sims, Annette Sunda, Nicole Spanovich, Richard Springer, Laurence A. Soderblom, Alicia Vaughan
2019, Journal of Geophysical Research E: Planets (124) 528-584
This paper provides an overview of Mars Exploration Rover Spirit Microscopic Imager (MI) operations and the calibration, processing, and analysis of MI data. The focus of this overview is on the last five Earth years (2005–2010) of Spirit's mission in Gusev crater, supplementing the previous overview of the first 450 sols of the Spirit MI...
Modeling White Sucker (Catostomus commersonii) populations to assess commercial harvest influence on age structure
Joseph D. Zydlewski, Meg Begley, Stephen Coghlan
2019, Journal of Freshwater Ecology (33) 413-428
Commercial harvest of White Suckers Catostomus commersonii for bait in the American Lobster Homarus americanus industry is minimally regulated in Maine and there are concerns as to the influence of increasing harvest. We built a population model using parameters (i.e. age-specific mortality, age at maturity, and size-specific fecundity) from literature...
Modelling effects of invasive species and drought on crayfish extinction risk and population dynamics
Allyson N. Yarra, Daniel D. Magoulick
2019, Aquatic Conservation: Marine and Freshwater Ecosystems (29) 1-11
Hydrological alteration, which may be exacerbated by climate change, is known to facilitate aquatic species invasion. Altered hydrology, invasive species, and the additive effects of these stressors pose a threat to aquatic biodiversity.Understanding extinction risk in the context of these stressors is crucial for prioritizing conservation efforts. As case...
Bioclimatic envelopes for individual demographic events driven by extremes: Plant mortality from drought and warming
Darin J. Law, Henry D. Adams, David D. Breshears, Neil S. Cobb, John B. Bradford, Chris B. Zou, Jason P. Field, Alfonso A. Gardea, A. Park Williams, Travis E. Huxman
2019, International Journal of Plant Sciences (80) 53-62
The occurrence of plant species across the globe is largely constrained by climate. Ecologists use plant-climate relationships such as bioclimatic envelopes and related niche models to determine potential environmental conditions promoting probable species occurrence. Traditionally bioclimatic envelopes either exclude disturbance explicitly, or only include disturbance as infrequent and smaller scale...
The extreme space weather event in September 1909
Hisashi Hayakawa, Yusuke Ebihara, Edward W. Cliver, Kentaro Hattori, Shin Toriumi, Jeffrey J. Love, Norio Umemura, Kosuke Namekata, Takahito Sakaue, Takuya Takahashi, Kazunari Shibata
2019, Monthly Notices of the Royal Astronomical Society (484) 4083-4099
We evaluate worldwide low-latitude auroral activity associated with the great magnetic storm of September 1909 for which a minimum Dst value of −595 nT has recently been determined. From auroral observations, we calculate that the equatorward boundary of the auroral oval in the 1909 event was in the range from 31°–35° invariant...
Extreme value-based methods for modeling elk yearly movements
Dhanushi A. Wijeyakulasuriya, Ephraim M. Hanks, Benjamin A. Shaby, Paul C. Cross
2019, Journal of Agricultural, Biological, and Environmental Statistics (24) 73-91
Species range shifts and the spread of diseases are both likely to be driven by extreme movements, but are difficult to statistically model due to their rarity. We propose a statistical approach for characterizing movement kernels that incorporate landscape covariates as well as the potential for heavy-tailed distributions. We used...
The future of recreational fisheries: Advances in science, monitoring, management, and practice
J. W. Brownscombe, K. Hyder, W. M. Potts, K. V. Wilson, Kevin L. Pope, A. J. Danylchuk, S. J. Cooke, Adrian Clarke, R. Arlinghaus, J. R. Postel
2019, Fisheries Research (211) 247-255
Recreational fisheries (RF) are complex social-ecological systems that play an important role in aquatic environments while generating significant social and economic benefits around the world. The nature of RF is diverse and rapidly evolving, including the participants, their priorities and behaviors, and the related ecological impacts and social and economic...
Early arc development recorded in Permian–Triassic plutons of the northern Mojave Desert region, California, USA
Robinson Cecil, Mary A. Ferrer, Nancy R. Riggs, Kathie Marsaglia, Andrew R. C. Kylander-Clark, Mihai N. Ducea, Paul Stone
2019, Geological Society of America Bulletin (131) 749-765
Permian–Middle Triassic plutons in the northern Mojave Desert, USA, are emplaced into the cryptic El Paso terrane, which is characterized by a northwest-striking belt of deep marine eugeoclinal strata juxtaposed against Proterozoic basement and its miogeoclinal cover. Fourteen new zircon U-Pb ages from the El...
Influence of climate, post‐treatment weather extremes, and soil factors on vegetation recovery after restoration treatments in the southwestern US
Stella M. Copeland, Seth M. Munson, John B. Bradford, Bradley J. Butterfield
2019, Applied Vegetation Science (22) 85-95
AimsUnderstanding the conditions associated with dryland vegetation recovery after restoration treatments is challenging due to a lack of monitoring data and high environmental variability over time and space. Tracking recovery trajectories with satellite‐based vegetation indices can strengthen predictions of restoration outcomes across broad areas with varying...
Trophic implications of a phenological paradigm shift: Bald eagles and salmon in a changing climate
Madeleine A. Rubenstein, Roger Christophersen, Jason I. Ransom
2019, Journal of Applied Ecology (56) 769-778
Climate change influences apex predators in complex ways, due to their important trophic position, capacity for resource plasticity, and sensitivity to numerous anthropogenic stressors. Bald eagles, an ecologically and culturally significant apex predator, congregate seasonally in high densities on salmon spawning rivers across the Pacific Northwest. One of the...
Spatial variability in ocean-mediated growth potential is linked to Chinook salmon survival
Mark J. Henderson, Jerome Fiechter, David D. Huff, Brian K. Wells
2019, Fisheries Oceanography (28) 334-344
Early ocean survival of Chinook salmon, Oncorhynchus tshawytscha, varies greatly inter-annually and may be the period during which later spawning abundance and fishery recruitment are set. Therefore, identifying environmental drivers related to early survival may inform better models for management and sustainability of salmon in a variable environment....
Europa’s ice tectonics: New insights from physical wax experiments with implications for subduction initiation and global resurfacing processes
Michael W Klasner, Juliane Gross, Sarah Tindall, Roy W. Schlishe, Christopher J. Potter
2019, Icarus (321) 593-607
Jupiter's Moon Europa has one of the youngest geological surfaces in our solar system with an age of 40–90 Ma, implying an intense history of resurfacing. The surface of Europa indeed shows abundant evidence of tectonic deformation related to extension, strike-slip, and shortening. However, observed features related to shortening are scarce compared with...
Interannual snow accumulation variability on glaciers derived from repeat spatially extensive ground-penetrating radar surveys
Daniel J McGrath, Louis Sass, Shad O’Neel, Christopher J. McNeil, Salvatore G Candela, Emily Baker, Hans P. Marshall
2019, The Cryosphere (12) 3617-3633
There is significant uncertainty regarding the spatiotemporal distribution of seasonal snow on glaciers, despite being a fundamental component of glacier mass balance. To address this knowledge gap, we collected repeat, spatially extensive high-frequency ground-penetrating radar (GPR) observations on two glaciers in Alaska for five consecutive years. GPR measurements showed steep...
Uncertainty in quantitative analyses of topographic change: Error propagation and the role of thresholding
Scott W. Anderson
2019, Earth Surface Processes and Landforms (44) 1015-1033
Topographic surveys inevitably contain error, introducing uncertainty into estimates of volumetric or mean change based on the differencing of repeated surveys. In the geomorphic community, uncertainty has often been framed as a problem of separating out real change from apparent change due purely to error, and addressed by removing measured...
