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Fine-grained sediments, or “fines,” are nearly ubiquitous in natural sediments, even in the predominantly coarse-grained sediments that host gas hydrates. Fines within these sandy sediments can be mobilized and subsequently clog flow pathways while methane is being extracted from gas hydrate as an energy resource. Using two-dimensional (2D) micromodels to test the conditions in which clogging occurs provides insights for choosing production operation parameters that optimize methane recovery in the field. During methane extraction, several processes can alter the mobility and clogging potential of fines: (1) fluid flow as the formation is depressurized to release methane from gas hydrate, (2) shifting pore-fluid...
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The 2008 - Present Ecosystem History of South Florida's Estuaries Database contains listings of all sites (modern and core) and modern monitoring site survey information (water chemistry, floral and faunal data, etc.). Three general types of data are contained within this database: 1) Modern Field Data (2008-present), 2) Master list of location information on all modern sites, and 3) Core data - location information. Data are available for modern sites (from 2008 to present) and cores in the general areas of Florida Bay, Biscayne Bay, and the southwest (Florida) coastal mangrove estuaries. Specific sites in the Florida Bay area include Taylor Creek, Bob Allen Key, Russell Bank, Pass Key, Whipray Basin, Rankin Bight,...
Categories: Data Release - Revised; Tags: 002, 004, 007, 008, 012, All tags...
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These data were collected from the TOPGUN-SODA10 2AK core collected in 2010 by LacCore (University of Minnesota), the USGS. and the University of California (U.C.) Berkeley. The 8.9 meter length core had stable isotopes of oxygen and carbon sampled every 10 millimeters or so, and diatoms samples at every 50 millimeters to 200 millimeters depending on the depth in the core. mineralogic data were collected using X-ray diffraction and grain-size analysis were done at various depths. These data are used to interpret the Holocene and late Pleistocene hydrology and paleoclimate of the lake and the region. The interpretation can be found in: Rosen, M.R., Reidy, L., Starratt, S., Zimmerman, S., in review, Middle Holocene...
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One of the primary goals of South Korea’s second Ulleung Basin Gas Hydrate Expedition (UBGH2) was to examine the geotechnical properties of the marine sediment associated with methane gas hydrate occurrences found offshore of eastern Korea in the Ulleung Basin, East Sea. Methane gas hydrate is a naturally occurring crystalline solid that sequesters methane in individual molecular cages formed by a lattice of water molecules. During UBGH2, concentrated gas hydrate was found in two sedimentary environments: gas hydrate was found in thin, coarse-grained sediment layers interbedded with fine-grained sediment (fines, such as clays and muds) and as veins of essentially pure gas hydrate within predominantly fine-grained...
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The urbanized area of downtown Menlo Park is subject to persistent flooding and sediment deposition by San Francisquito Creek in South San Francisco Bay. To mitigate these events, a suite of cores was collected in 2002 at the mouth of the creek to determine sediment depositional rates on the delta. One of those cores (721-1) was selected for microbiological (pollen, diatoms, and foraminifera) and geochemical analyses to reconstruct a depositional record over the past two millennia. This data release provides radiocarbon dates, census counts of benthic foraminifera, diatoms, and palynomorphs, and the measurement of anthropogenic metals and other elements in sediments from this core.
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The safety, effectiveness and longevity of many construction and geotechnical engineering projects rely on correctly accounting for the evolution of soil properties over time. Critical sediment properties, such as compressibility, can change in response to pore-fluid chemistry changes, particularly if the sediment contains appreciable concentrations of fine-grained materials. Pore-fluid changes act at the micro scale, altering interactions between sediment particles, or between sediment particles and the pore fluid. These micro-scale alterations change how sediment fabrics and void ratios develop, which directly impacts macro-scale properties such as sediment compressibility. The goal of this study is to correlate...
In 1991, the U.S. Geological Survey (USGS) began a study of more than 50 major river basins across the Nation as part of the National Water-Quality Assessment (NAWQA) project of the National Water Quality Program. One of the major goals of the NAWQA project is to determine how water quality and ecological conditions change over time. To support that goal, long-term consistent and comparable ecological monitoring has been conducted on streams and rivers throughout the Nation. Fish, invertebrate, and algae data collected as part of the NAWQA program were retrieved from the USGS Aquatic Bioassessment database for use in trend analysis. Ultimately, these data will provide insight into how natural features and human...
Survival and size of mayflies at each life stage, as well as MeHg concentrations in diatoms and mayflies exposed to low and high MeHg concentrations and a range of selenomethione (SeMet) concentrations.
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The objective of this study was to assess the comparative influence of multiple stressors on benthic diatoms at 98 sites that spanned a range of stressors that occurred in an agricultural dominated region in the upper Midwest, USA. The primary stressors of interest included: nutrients, herbicides and fungicides, sediment, and streamflow; though the influence of physical habitat was incorporated in the assessment. The study area covered portions of 12 states (600,000 km2), with agriculture the dominate land use. The 98 sites used in this study consisted of 49 randomly selected EPA National Rivers and Streams Assessment sites combined with 49 targeted USGS sites. Thirty-seven of the targeted sites were selected to...
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The safety, effectiveness and longevity of many construction and geotechnical engineering projects rely on correctly accounting for the evolution of soil properties over time. Critical sediment properties, such as compressibility, can change in response to pore-fluid chemistry changes, particularly if the sediment contains appreciable concentrations of fine-grained materials. Pore-fluid changes act at the micro scale, altering interactions between sediment particles, or between sediment particles and the pore fluid. These micro-scale alterations change how sediment fabrics and void ratios develop, which directly impacts macro-scale properties such as sediment compressibility. The goal of this study is to correlate...
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Detecting trends in biological attributes is central to many stream monitoring programs; however, understanding how natural variability in environmental factors affects trend results is not well understood. We evaluated the influence of antecedent streamflow and sample timing (covariates) on trend estimates for fish, invertebrate, and diatom taxa richness and biological condition from 2002 to 2012 at 51 sites distributed across the conterminous United States. This data release contains all of the input and output files necessary to reproduce the results presented and discussed in the associated journal article.
In 1991, the U.S. Geological Survey (USGS) began a study of more than 50 major river basins across the Nation as part of the National Water-Quality Assessment (NAWQA) project of the National Water Quality Program. One of the major goals of the NAWQA project is to determine how water quality and ecological conditions change over time. To support that goal, long-term consistent and comparable ecological monitoring has been conducted on streams and rivers throughout the Nation. Fish, invertebrate, and algae data collected as part of the NAWQA program were retrieved from the USGS Aquatic Bioassessment database for use in trend analysis. Ultimately, these data will provide insight into how natural features and human...
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Aquatic ecological surveys are valuable to understanding the interaction between the biotic and abiotic components in rivers and streams. However, large-scale assessments of the water chemistry, geomorphology, and ecological community are usually not feasible due to limited resources. Beginning in 2013, the Regional Stream Quality Assessment Project of the US Geological Survey’s National Water Quality Program, began sampling 89-120 streams in each of 5 regions across the conterminous United States—the Midwest (2013), Southeast (2014), Pacific Northwest (2015), Northeast (2016), and California (2017). Sampling included water and streambed sediment chemistry, stage and temperature (Journey and others, 2015). The abiotic...
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The 1995 - 2007 Ecosystem History of South Florida's Estuaries Database contains listings of all sites (modern and core), modern monitoring site survey information (water chemistry, floral and faunal data, bottom type, etc.), and published core data. Three general types of data are contained within this database: 1) Modern Field Data (1995-2007), 2) Master list of location information on all modern sites, and 3) Core data - faunal assemblages and location information. Data are available for modern sites and cores in the general areas of Florida Bay, Biscayne Bay, and the southwest (Florida) coastal mangrove estuaries. Specific sites in the Florida Bay area include Taylor Creek, Bob Allen Key, Russell Bank, Pass...
Categories: Data Release - Revised; Tags: 002, 004, 007, 008, 012, All tags...
In 1991, the U.S. Geological Survey (USGS) began a study of more than 50 major river basins across the Nation as part of the National Water-Quality Assessment (NAWQA) project of the National Water Quality Program. One of the major goals of the NAWQA project is to determine how water quality and ecological conditions change over time. To support that goal, long-term consistent and comparable ecological monitoring has been conducted on streams and rivers throughout the Nation. Fish, invertebrate, and algae data collected as part of the NAWQA program were retrieved from the USGS Aquatic Bioassessment database for use in trend analysis. Ultimately, these data will provide insight into how natural features and human...
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Detecting trends in biological attributes is central to many stream monitoring programs; however, understanding how natural variability in environmental factors affects trend results is not well understood. We evaluated the influence of antecedent streamflow and sample timing (covariates) on trend estimates for fish, invertebrate, and diatom taxa richness and biolgical condition from 2002 to 2012 at 51 sites distributed across the conterminous United States. This data release contains all of the input and output files necessary to reproduce the results presented and discussed in the associated journal article.
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One of the primary goals of South Korea’s second Ulleung Basin Gas Hydrate Expedition (UBGH2) was to examine the geotechnical properties of the marine sediment associated with methane gas hydrate occurrences found off the shore of eastern Korea in the Ulleung Basin, East Sea. Methane gas hydrate is a naturally occurring crystalline solid that sequesters methane in individual molecular cages formed by a lattice of water molecules. During UBGH2, concentrated gas hydrate was found in two sedimentary environments: thin, coarse-grained sediment layers interbedded with fine-grained sediment (fines, such as clays and muds) and as veins of essentially pure gas hydrate within beds of predominantly fine-grained sediment....
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The East Pisco Basin is one of several forearc basins situated on the coastal plain of Peru between the Andean Cordillera and Peru-Chile Trench. During the Cenozoic, successive marine transgressions across the East Pisco Basin deposited sequences of Paleogene and Neogene age. Biochronologic studies suggest that a hiatus of approximately 12 million years (~32-20 Ma) separates the youngest Paleogene deposits from the oldest Neogene deposits. A newly recognized lower Miocene sequence, provisionally named the Tunga Formation, shortens that hiatus. The following database provides location and description of samples from the East Pisco Basin, checklists of microfossil assemblages, and taxonomic notes for those assemblages.
    map background search result map search result map Data on Midwest stream diatom metrics and environmental stressors, 2013 Southeast Regional Stream Quality Assessment Ecological Data 2D micromodel studies of pore-throat clogging by pure fine-grained sediments and natural sediments from NGHP-02, offshore India Datasets used to evaluate the effects of antecedent streamflow and sample timing on trend assessments of fish, invertebrate and diatom communities across the United States, 2002-12 (input) Datasets used to evaluate the effects of antecedent streamflow and sample timing on trend assessments of fish, invertebrate and diatom communities across the United States, 2002-12 (output) 1995 - 2007 Ecosystem History of South Florida's Estuaries Database (ver. 1.1, June 2022) 2008 - Present Ecosystem History of South Florida's Estuaries Database (ver. 2.0, June 2022) Mineralogic, grain-size, biologic, and stable isotopic analyses of core TOPGUN-SODA10 2A-K from Big Soda Lake, Nevada, USA Survival, growth, behavior and mercury concentrations of mayflies exposed to elevated dietary methylmercury and aqueous selenium Ecological community datasets used to evaluate the presence of trends in ecological communities in selected rivers and streams across the United States, 1992–2017 Ecological community datasets used to evaluate the presence of trends in ecological communities in selected rivers and streams across the United States, 1992–2017 (input) Ecological community datasets used to evaluate the presence of trends in ecological communities in selected rivers and streams across the United States, 1992–2017 (output) Dataset of diatom controls on the compressibility and permeability of fine-grained sediment collected offshore of South Korea during the Second Ulleung Basin Gas Hydrate Expedition, UBGH2 Dataset of diatom controls on the sedimentation behavior of fine-grained sediment collected offshore of South Korea during the Second Ulleung Basin Gas Hydrate Expedition, UBGH2 Radiocarbon measurements, census counts of benthic foraminifera, diatoms, and palynomorphs, and geochemistry from core 721-1 obtained in 2002 off San Francisquito Creek in South San Francisco Bay Census counts of diatoms from core 721-1 obtained in 2002 off San Francisquito Creek in South San Francisco Bay Microfossil Samples from the East Pisco Basin, southern Peru Survival, growth, behavior and mercury concentrations of mayflies exposed to elevated dietary methylmercury and aqueous selenium Mineralogic, grain-size, biologic, and stable isotopic analyses of core TOPGUN-SODA10 2A-K from Big Soda Lake, Nevada, USA Radiocarbon measurements, census counts of benthic foraminifera, diatoms, and palynomorphs, and geochemistry from core 721-1 obtained in 2002 off San Francisquito Creek in South San Francisco Bay 2D micromodel studies of pore-throat clogging by pure fine-grained sediments and natural sediments from NGHP-02, offshore India 1995 - 2007 Ecosystem History of South Florida's Estuaries Database (ver. 1.1, June 2022) 2008 - Present Ecosystem History of South Florida's Estuaries Database (ver. 2.0, June 2022) Southeast Regional Stream Quality Assessment Ecological Data Data on Midwest stream diatom metrics and environmental stressors, 2013 Microfossil Samples from the East Pisco Basin, southern Peru Ecological community datasets used to evaluate the presence of trends in ecological communities in selected rivers and streams across the United States, 1992–2017 Ecological community datasets used to evaluate the presence of trends in ecological communities in selected rivers and streams across the United States, 1992–2017 (input) Ecological community datasets used to evaluate the presence of trends in ecological communities in selected rivers and streams across the United States, 1992–2017 (output) Datasets used to evaluate the effects of antecedent streamflow and sample timing on trend assessments of fish, invertebrate and diatom communities across the United States, 2002-12 (input) Datasets used to evaluate the effects of antecedent streamflow and sample timing on trend assessments of fish, invertebrate and diatom communities across the United States, 2002-12 (output)