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A statistical learning framework for groundwater nitrate models of the Central Valley, California, USA
Bernard T. Nolan, Michael N. Fienen, David L. Lorenz
2015, Journal of Hydrology (531) 902-911
We used a statistical learning framework to evaluate the ability of three machine-learning methods to predict nitrate concentration in shallow groundwater of the Central Valley, California: boosted regression trees (BRT), artificial neural networks (ANN), and Bayesian networks (BN). Machine learning methods can learn complex patterns in the data but because...
Simulation of the effects of different inflows on hydrologic conditions in Lake Houston with a three-dimensional hydrodynamic model, Houston, Texas, 2009–10
Samuel H. Rendon, Michael T. Lee
2015, Scientific Investigations Report 2015-5153
Lake Houston, an important water resource for the Houston, Texas, area, receives inflows from seven major tributaries that compose the San Jacinto River Basin upstream from the reservoir. The effects of different inflows from the watersheds drained by these tributaries on the residence time of water in Lake Houston and...
Reviews and syntheses: Effects of permafrost thaw on Arctic aquatic ecosystems
J.E. Vonk, S.E. Tank, W.B. Bowden, I. Laurion, W.F. Vincent, P. Alekseychik, Y. Amyot, M.F. Billet, J. Canario, R.M. Cory, B.N. Deshpande, M. Helbig, M. Jammet, J. Karlsson, J. Larouche, G. MacMillan, Milla Rautio, K.M. Walter Anthony, Kimberly P. Wickland
2015, Biogeosciences (12) 7129-7167
The Arctic is a water-rich region, with freshwater systems covering about 16 % of the northern permafrost landscape. Permafrost thaw creates new freshwater ecosystems, while at the same time modifying the existing lakes, streams, and rivers that are impacted by thaw. Here, we describe the current state of knowledge...
Occurrence and transport of selected constituents in streams near the Stibnite mining area, Central Idaho, 2012–14
Alexandra B. Etheridge
2015, Scientific Investigations Report 2015-5166
Mining of stibnite (antimony sulfide), tungsten, gold, silver, and mercury near the town of Stibnite in central Idaho has left a legacy of trace element contamination in local streams. Water-quality and streamflow monitoring data from a network of five streamflow-gaging stations were used to estimate trace-element and suspended-sediment loads and...
Stream geomorphic and habitat data from a baseline study of Underwood Creek, Wisconsin, 2012
Benjamin M. Young, Faith A. Fitzpatrick, James D. Blount
2015, Data Series 947
Geomorphic and habitat data were collected along Underwood Creek as part of a larger study of stream water quality conditions in the greater Milwaukee, Wisconsin, area. The data were collected to characterize baseline physical conditions in Underwood Creek prior to a potential discharge of wastewater return flow to the stream...
Characterization of hydrology and water quality of Piceance Creek in the Alkali Flat area, Rio Blanco County, Colorado, March 2012
Judith C. Thomas
2015, Scientific Investigations Report 2015-5147
Previous studies by the U.S. Geological Survey identified Alkali Flat as an area of groundwater upwelling, with increases in concentrations of total dissolved solids, and streamflow loss, but additional study was needed to better characterize these observations. The U.S. Geological Survey, in cooperation with the Bureau of Land Management, White...
Hydrodynamic assessment data associated with the July 2010 line 6B spill into the Kalamazoo River, Michigan, 2012–14
Paul C. Reneau, David T. Soong, Christopher J. Hoard, Faith A. Fitzpatrick
2015, Open-File Report 2015-1205
Hydrodynamic-assessment data for the Kalamazoo River were collected by the U.S. Geological Survey (USGS) during 2012–14 to augment other hydrodynamic data-collection efforts by Enbridge Energy L.P. and the U.S. Environmental Protection Agency associated with the 2010 Enbridge Line 6B oil spill. Specifically, the USGS data-collection efforts were focused on additional...
Regional implications of new chronostratigraphic and paleogeographic data from the Early Permian Darwin Basin, east-central California
Calvin H. Stevens, Paul Stone, Robert T. Magginetti
2015, Stratigraphy (12) 149-166
The Darwin Basin developed in response to episodic subsidence of the western margin of the Cordilleran continental shelf from Late Pennsylvanian (Gzhelian) to Early Permian (late Artinskian) time. Subsidence of the basin was initiated in response to continental truncation farther to the west and was later augmented by thrust emplacement...
Stratigraphy and paleogeographic significance of a Late Pennsylvanian to Early Permian channeled slope sequence in the Darwin Basin, southern Darwin Hills, east-central California
Calvin H. Stevens, Paul Stone, Robert T. Magginetti, Scott M. Ritter
2015, Stratigraphy (12) 185-196
The complex stratigraphy of late Paleozoic rocks in the southern Darwin Hills consists of regionally extensive Mississippian and Early to Middle Pennsylvanian rocks overlain by latest Pennsylvanian to Early Permian rocks, herein called the Darwin Hills sequence. Deposition of this latter sequence marked the beginning of the Darwin Basin. In...
Underwater videography outperforms above-water videography and in-person surveys for monitoring the spawning of Devils Hole Pupfish
Ambre L. Chaudoin, Olin Feuerbacher, Scott A. Bonar, Paul J. Barrett
2015, North American Journal of Fisheries Management (35) 1252-1262
The monitoring of threatened and endangered fishes in remote environments continues to challenge fisheries biologists. The endangered Devils Hole Pupfish Cyprinodon diabolis, which is confined to a single warm spring in Death Valley National Park, California–Nevada, has recently experienced record declines, spurring renewed conservation and recovery efforts. In February–December 2010, we...
Paleoreconstruction of organic carbon inputs to an oxbow lake in the Mississippi River watershed: Effects of dam construction and land use change on regional inputs
Thomas S. Bianchi, Valier Galy, Brad E. Rosenheim, Michael Shields, Xingquan Cui, Peter C. Van Metre
2015, Geophysical Research Letters (42) 7983-7991
We use a dated sediment core from Lake Whittington (USA) in the lower Mississippi River to reconstruct linkages in the carbon cycling and fluvial sediment dynamics over the past 80 years. Organic carbon (OC) sources were characterized using bulk (δ13C, ramped pyrolysis-oxidation (PyrOx) 14C, δ15N, and TN:OC ratios) and compound-specific (lignin phenols...
Coral 13C/12C records of vertical seafloor displacement during megathrust earthquakes west of Sumatra
Michael K. Gagan, Sindia M. Sosdian, Heather Scott-Gagan, Kerry Sieh, Wahyoe S. Hantoro, Danny H. Natawidjaja, Richard W. Briggs, Bambang W. Suwargadi, Hamdi Rifai
2015, Earth and Planetary Science Letters (432) 461-471
The recent surge of megathrust earthquakes and tsunami disasters has highlighted the need for a comprehensive understanding of earthquake cycles along convergent plate boundaries. Space geodesy has been used to document recent crustal deformation patterns with unprecedented precision, however the production of long paleogeodetic records of vertical seafloor motion is...
Classification of ephemeral, intermittent, and perennial stream reaches using a TOPMODEL-based approach
Tanja N. Williamson, Carmen T. Agouridis, Christopher D. Barton, Jonathan A. Villines, Jeremiah G. Lant
2015, Journal of the American Water Resources Association (51) 1739-1759
Whether a waterway is temporary or permanent influences regulatory protection guidelines, however, classification can be subjective due to a combination of factors, including time of year, antecedent moisture conditions, and previous experience of the field investigator. Our objective was to develop a standardized protocol using publicly available spatial information to classify...
Regression Equations for Monthly and Annual Mean and Selected Percentile Streamflows for Ungaged Rivers in Maine
Robert W. Dudley
2015, Scientific Investigations Report 2015-5151
In an effort to delineate hydrologic conditions in Maine, the U.S. Geological Survey, in cooperation with the Maine Department of Transportation, used streamflow data to develop dependent variables for 130 regression equations for estimating monthly and annual mean and 1, 5, 10, 25, 50, 75, 90, 95, and 99 percentile...
Uranium-series ages of fossil corals from Mallorca, Spain: The "Neotyrrhenian" high stand of the Mediterranean Sea revisited
Daniel R. Muhs, Kathleen R. Simmons, Naomi Porat
2015, Palaeogeography, Palaeoclimatology, Palaeoecology (438) 408-424
The emergent marine deposits of the Mediterranean basin have been recognized as an important record of Quaternary sea level history for more than a century. Previous workers identified what have been interpreted to be two separate high stands of sea in the late Quaternary, namely the “Eutyrrhenian” (thought to...
California State Waters Map Series — Offshore of Fort Ross, California
Samuel Y. Johnson, Peter Dartnell, Nadine E. Golden, Stephen R. Hartwell, Mercedes D. Erdey, H. Gary Greene, Guy R. Cochrane, Rikk G. Kvitek, Michael W. Manson, Charles A. Endris, Bryan E. Dieter, Janet Watt, Lisa M. Krigsman, Ray W. Sliter, Erik N. Lowe, John L. Chin
Samuel Y. Johnson, Susan A. Cochran, editor(s)
2015, Open-File Report 2015-1211
Introduction In 2007, the California Ocean Protection Council initiated the California Seafloor Mapping Program (CSMP), designed to create a comprehensive seafloor map of high-resolution bathymetry, marine benthic habitats, and geology within the 3-nautical-mile limit of California’s State Waters. The CSMP approach is to create highly detailed seafloor maps through collection, integration,...
Biodegradability of dissolved organic carbon in permafrost soils and aquatic systems: a meta-analysis
Jorien E. Vonk, Suzanne E. Tank, Paul J. Mann, Robert G.M. Spencer, Claire C. Treat, Robert G. Striegl, Benjamin W. Abbott, Kimberly P. Wickland
2015, Biogeosciences (12) 6915-6930
As Arctic regions warm and frozen soils thaw, the large organic carbon pool stored in permafrost becomes increasingly vulnerable to decomposition or transport. The transfer of newly mobilized carbon to the atmosphere and its potential influence upon climate change will largely depend on the degradability of carbon delivered to aquatic...
Variability within nearshore ecosystems of the Gulf of Alaska
Brenda E. Ballachey, James L. Bodkin, Heather A. Coletti, Thomas A Dean, Daniel Esler, George G. Esslinger, Katrin Iken, Kimberly A. Kloecker, Brenda Konar, Mandy Lindeberg, Daniel Monson, Marnie Shepherd, Ben P. Weitzman
2015, Report, Quantifying temporal and spatial ecosystem variability across the northern Gulf of Alaska to understand mechanisms of change. Science synthesis report for the Gulf Watch Alaska Program
Nearshore marine habitats, which represent the interface among air, land and sea, form a critical component of the Gulf of Alaska (GOA) ecosystem. As an interface, the nearshore facilitates transfer of water, nutrients and biota between terrestrial and oceanic systems, creating zones of high productivity. The nearshore provides a variety...
Early Permian conodont fauna and stratigraphy of the Garden Valley Formation, Eureka County, Nevada
Bruce R. Wardlaw, Dora M. Gallegos, Valery V. Chernykh, Walter S. Snyder
2015, Stratigraphy (12) 197-215
The lower Part of the Garden Valley Formation yields two distinct conodont faunas. One of late Asselian age dominated by Mesogondolella and Streptognathodus and one of Artinskian age dominated by Sweetognathus with Mesogondolella. The Asselian fauna contains the same species as those found in the type area of the Asselian...
Evaluating predictors of local dabbling duck abundance during migration: Managing the spectrum of conditions faced by migrants
Kevin Aagaard, Shawn M. Crimmins, Wayne E. Thogmartin, Brian G. Tavernia, James E. Lyons
2015, Wildfowl (65) 100-120
The development of robust modelling techniques to derive inferences from large-scale migratory bird monitoring data at appropriate scales has direct relevance to their management. The Integrated Waterbird Management and Monitoring programme (IWMM) represents one of the few attempts to monitor migrating waterbirds across entire flyways using targeted local surveys. This...
Depth, ice thickness, and ice-out timing cause divergent hydrologic responses among Arctic lakes
Christopher D. Arp, Benjamin M. Jones, Anna K. Liljedahl, Kenneth M. Hinkel, Jeffery A. Welker
2015, Water Resources Research (51) 9379-9401
Lakes are prevalent in the Arctic and thus play a key role in regional hydrology. Since many Arctic lakes are shallow and ice grows thick (historically 2-m or greater), seasonal ice commonly freezes to the lake bed (bedfast ice) by winter's end. Bedfast ice fundamentally alters lake energy balance and...
Non-invasive flow path characterization in a mining-impacted wetland
James Bethune, Jackie Randell, Robert L. Runkel, Kamini Singha
2015, Journal of Contaminant Hydrology (183) 29-39
Time-lapse electrical resistivity (ER) was used to capture the dilution of a seasonal pulse of acid mine drainage (AMD) contamination in the subsurface of a wetland downgradient of the abandoned Pennsylvania mine workings in central Colorado. Data were collected monthly from mid-July to late October of 2013, with an additional...
A new record of the late Pleistocene coral Pocillopora palmata from the Dry Tortugas, Florida reef tract, USA
Lauren T. Toth, Ilsa B. Kuffner, Hai Cheng, R. Lawrence Edwards
2015, Palaios (30) 827-835
Pocilloporid corals dominated shallow-water environments in the Caribbean during much of the Cenozoic; however, the regional diversity of this family declined over the last 15 My, culminating with the extinction of its final member, Pocillopora palmata, during the latest Pleistocene. Here we present a new record of P. palmata from...
U.S. Geological Survey National Water Census: Colorado River Basin Geographic Focus Area Study
Breton W. Bruce, David W. Clow, Molly A. Maupin, Matthew P. Miller, Gabriel B. Senay, Graham A. Sexstone, David D. Susong
2015, Fact Sheet 2015-3080
Introduction The U.S. Geological Survey’s (USGS) concept of a national census (or accounting) of water resources has evolved over the last several decades as the Nation has experienced increasing concern over water availability for multiple competing uses. The implementation of a USGS National Water Census was described in the USGS 2007...