Filters: Tags: Organic Carbon (X)
14 results (15ms)|
Filters
Contacts
(Less)
|
Variability in sediment properties with depth and the thickness of individual sedimentary layers are critical determinants of seabed acoustic response. The New England Mud Patch (NEMP), located south of Cape Cod, is an unusual feature on the U.S. Continental Shelf in that it is composed of fine-grained sediment layers containing a relatively-homogeneous mix of sand, silt, and clay-sized particles bounded by more typical sandy shelf sediments. The unique characteristics and nature of this deposit is due to a derivation of sediments that have been transported to, and deposited in, a basal bowl-shaped depression since the last glacial maximum. Ninety-two piston, vibra-, and gravity cores with a maximum length of 8.2...
This product consists of one tabular dataset and associated metadata of water quality information related to rivers, streams, and reservoirs in the Upper Mississippi River watershed between 2012 and 2016. This data release is a part of a national assessment of freshwater aquatic carbon fluxes. Data consist of organic and inorganic carbon related species, carbon dioxide and methane gas fluxes calculated from manual chamber measurements, nitrogen species, carbon isotopes, oxygen isotopes, cations, anions, trace metals, and various in situ measurements including: pH, water temperature, air temperature, barometric pressure, dissolved oxygen, turbidity, fluorescent dissolved organic matter, and specific conductance....
Categories: Data,
Project;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Carbon,
Fluorescent Dissolved Organic Matter (fDOM),
Minnesota,
Shingobee,
Shingobee Headwaters Aquatic Ecosystems Project,
Carbon dioxide is increasing in the atmosphere, presumably from human activities. Many soils on Walnut Gulch Experimental Watershed (WGEW) in southeastern Arizona contain carbonates that have accumulated over long periods of time. The hypothesis is that these soils are maintaining this carbon pool under present climatic conditions and are a sink for some of the increasing atmospheric carbon. Bowen ratio systems were used to measure CO2 fluxes from a brush and a grass community with different soil types on WGEW. Contradictory to the hypothesis, the two sites were found to be losing carbon annually. The brush site with higher inorganic carbon in the soil, had an average annual loss of 144 g C m-2 and the grass site...
Categories: Publication;
Types: Citation;
Tags: carbon dioxide,
inorganic carbon,
organic carbon,
rangeland
Twenty-four piston cores (and associated trigger cores) were collected from the source zone of the Currituck Landslide Complex and upper slope adjacent to Baltimore Canyon by the U.S. Geological Survey and the University of Rhode Island Department of Ocean Engineering during an eight-day cruise aboard the R/V Hugh R. Sharp in September/October of 2012. These cores were analyzed for evidence of seafloor mass transport processes, with an emphasis on constraining the age and shallow stratigraphy of the landslide complex. Sedimentological and geotechnical characterization of the cores was carried out through whole core imaging and description, followed by analysis of discrete samples at the USGS Woods Hole Coastal and...
Variability in sediment properties with depth and the thickness of individual sedimentary layers are critical determinants of seabed acoustic response. The New England Mud Patch (NEMP), located south of Cape Cod, is an unusual feature on the U.S. Continental Shelf in that it is composed of fine-grained sediment layers containing a relatively-homogeneous mix of sand, silt, and clay-sized particles bounded by more typical sandy shelf sediments. The unique characteristics and nature of this deposit is due to a derivation of sediments that have been transported to, and deposited in, a basal bowl-shaped depression since the last glacial maximum. Ninety-two piston, vibra-, and gravity cores with a maximum length of 8.2...
Abstract: Dissolved inorganic nitrogen (DIN) retention-transport through a headwater catchment was synthesized from studies encompassing four distinct hydrologic zones of the Shingobee River Headwaters near the origin of the Mississippi River. The hydrologic zones included: (1) hillslope ground water (ridge to bankside riparian); (2) alluvial riparian ground water; (3) ground water discharged through subchannel sediments (hyporheic zone); and (4) channel surface water. During subsurface hillslope transport through Zone 1, DIN, primarily nitrate, decreased from ∼3 mg-N/l to <0.1 mg-N/l. Ambient seasonal nitrate:chloride ratios in hillslope flow paths indicated both dilution and biotic processing caused nitrate loss....
Categories: Publication;
Types: Citation;
Tags: Denitrification,
Nitrate,
headwaters,
organic carbon
How do glaciers impact Alaska’s coastal ecosystems, and what do glacier changes mean for the future of this ecologically and economically valuable system?
Abstract (from http://www.nature.com/nature/journal/v520/n7546/full/nature14338.html): Large quantities of organic carbon are stored in frozen soils (permafrost) within Arctic and sub-Arctic regions. A warming climate can induce environmental changes that accelerate the microbial breakdown of organic carbon and the release of the greenhouse gases carbon dioxide and methane. This feedback can accelerate climate change, but the magnitude and timing of greenhouse gas emission from these regions and their impact on climate change remain uncertain. Here we find that current evidence suggests a gradual and prolonged release of greenhouse gas emissions in a warming climate and present a research strategy with which to...
Categories: Publication;
Types: Citation;
Tags: Alaska CASC,
Biogeochemistry,
Climate Change,
Data Visualization & Tools,
Organic Carbon,
Coastal communities are uniquely vulnerable to sea-level rise (SLR) and severe storms such as hurricanes. These events enhance the dispersion and concentration of natural and anthropogenic chemicals and pathogenic microorganisms that could adversely affect the health and resilience of coastal communities and ecosystems in coming years. The U.S. Geological Survey has developed the Sediment-Bound Contaminant Resiliency and Response (SCoRR) strategy to define baseline and post-event sediment-bound environmental health (EH) stressors. These data document the major element chemistry, major and trace chemical composition, total sulfur content, inorganic and organic carbon for soil and sediment samples from selected stations...
This data set includes a variety of bulk organic carbon, lignin-phenol biomarker, and sedimentation rate data from a set of sites in the Blackwater Marsh in Chesapeake Bay. At each site, a short core was taken, and all data is organized according to depth below the marsh surface. Data includes: Bulk %OC, bulk %N, atomic carbon:nitrogen ratios, stable carbon isotopes (d13C) Lignin-phenol biomarker parameters, including 8, Ad:Alv, C:V, S:V, and the individual concentrations of each lignin-phenol (in lambda units, or mg per 100 mg OC). Pb-210 and Cs-137 activities Sediment bulk densities In addition to the sediment core data, we are also including d13C values from vegetation samples collected from each of the marsh...
Categories: Data;
Tags: 13C,
Blackwater National Wildlife Refuge,
Chesapeake Bay,
Ecology,
Sedimentation rates,
Total and organic carbon values from soil samples taken from the Yukon River Basin, Alaska. These samples were used to create a relationship between total carbon and organic carbon for samples which were only run for total carbon.
The Alaska Geochemical Database Version 4.0 (AGDB4) contains geochemical data compilations in which each geologic material sample has one best value determination for each analyzed species, greatly improving efficiency of use. The relational database includes historical geochemical data archived in the USGS National Geochemical Database (NGDB), the Atomic Energy Commission National Uranium Resource Evaluation (NURE) Hydrogeochemical and Stream Sediment Reconnaissance databases, and the Alaska Division of Geological and Geophysical Surveys (DGGS) Geochemistry database. Data from the U.S. Bureau of Mines and the U.S. Bureau of Land Management are included as well. The data tables describe historical and new quantitative...
The Alaska Geochemical Database Version 3.0 (AGDB3) contains new geochemical data compilations in which each geologic material sample has one best value determination for each analyzed species, greatly improving speed and efficiency of use. Like the Alaska Geochemical Database Version 2.0 before it, the AGDB3 was created and designed to compile and integrate geochemical data from Alaska to facilitate geologic mapping, petrologic studies, mineral resource assessments, definition of geochemical baseline values and statistics, element concentrations and associations, environmental impact assessments, and studies in public health associated with geology. This relational database, created from databases and published...
Categories: Data,
Data Release - Revised;
Types: Downloadable,
Map Service,
OGC WFS Layer,
OGC WMS Layer,
Shapefile;
Tags: AGDB,
AMRAP,
Alaska Geochemical Database,
Alaska Mineral Resource Assessment Program,
Alaska Range,
This data release contains data from cores collected in marshes and in sediments under invasive Brazilian waterweed (Egeria densa Planchon) in the Sacramento-San Joaquin Delta of California during the spring of 2018. Data are provided in two text files in comma separated columns. The first Core_Sites_Details.txt contains core site location, collection dates, and naming information. The second file, Core_Section_Analyses.txt contains % organic carbon, % inorganic sediment, bulk density data for each 2-cm section of six peat cores collected in marshes and six sediment cores collected under patches of Brazilian waterweed. Additionally, the second file contains the radioisotope values (137Cs and 210Pb) for each of the...
Categories: Data;
Tags: California,
Lindsey Slough,
Middle River,
Mokelumne River,
Sacramento-San Joaquin Delta,
|
|
