Filters: Tags: {"type":"USGS Scientific Topic Keyword"} (X) > partyWithName: U.S. Geological Survey - ScienceBase (X) > partyWithName: U.S. Geological Survey (X)
629 results (105ms)|
Filters
Date Range
Extensions Types
Contacts
Categories
Tags (with Type=USGS Scientific Topic Keyword ) |
Temporal and spatial sources of silica for chert remain poorly constrained. Modern sources to the worlds oceans include silica in rivers > aeolian (dust) deposition > sea floor vents and submarine weathering. However, changes in aridity and dust flux during the Phanerozoic may explain variations in the ocean silica cycle and times and places of chert formation. The chemistry of fine quartz dust (FQD) provides a chemical mechanism for the transformation of FQD to polymorphs of silica in chert; FQD is readily dissolved, then reprecipitated as Opal-A by either biotic or abiotic processes. An unequivocal relation between increases in dust flux and biogenic opal-A in the western Pacific Ocean during the past 200 kyr...
These data were compiled during a laboratory experiment showing the turbidity response to increasing silt and clay concentration. The sediment used for the laboratory experiment was collected in the Grand Canyon study area, from the bank of the Little Colorado River, approximately 1 kilometer upstream from its confluence with the Colorado River. The sediment was passed through a 63 µm sieve to isolate the silt-and-clay-size fraction. The silt and clay was completely dried in an oven (at 105 degrees Celsius for 12 hours), weighed, mechanically disaggregated, and added in stages to a measured volume of water to calculate concentration. The sediment was kept in suspension with an electric stirrer and turbidity was...
The point data file ("Soda Fire Point and Pasture Data (2016).Point Data.csv") includes 2016 vegetative cover values of exotic annual grass and perennial grass measured within three different types of plots for 75 pastures in the Soda Fire, which burned in 2015: 6m² plot using a grid-point intercept photo software, SamplePoint (Booth et al. 2006), 1m² quadrat using an unguided rapid ocular estimate in the field, 531m² circular plot using an unguided rapid ocular estimate in the field. Smaller plots were nested within larger plots. The pasture data file ("Soda Fire Point and Pasture Data (2016).Pasture Data.csv") includes pasture level metrics of area, elevation, precipitation, slope, heatload, soils, and herbicide...
Note: This dataset has been revised and superseded by version 2.0, available here: https://doi.org/10.5066/P90PG34S. Remote sensing based maps of tidal marshes, both of their extents and carbon stocks, have the potential to play a key role in conducting greenhouse gas inventories and implementing climate mitigation policies. Our objective was to generate a single remote sensing model of tidal marsh aboveground biomass and carbon that represents nationally diverse tidal marshes within the conterminous United States (CONUS). To meet this objective we developed the first national-scale dataset of aboveground tidal marsh biomass, species composition, and aboveground plant carbon content (%C) from six CONUS regions:...
The dataset consists of site identification, location, temperature and CO2 flux from diffuse emission measurement at the Tiptop fire. A total of 40 CO2 flux measurements were made at 27 locations, including five points (seven measurements) outside of the active coal fire area.
Categories: Data;
Tags: Energy Resources,
Environmental Health,
Kentucky,
Perry County,
USGS Science Data Catalog (SDC),
These data describe the catch and biological data from 363 bottom-set gill-net lifts distributed throughout Lake Michigan (including main basin and Green Bay) between April and November in 1930–1932. Data collected from the R/V Fulmar were recorded in notebooks and are now archived at the U.S. Geological Survey’s Great Lakes Science Center. Each lift included 1–7 gangs of linen gill nets. Each gang comprised 3–5 panels each having a length of 155 m, a height of 1.5 m, and a (stretch-)mesh size of either 60, 64, 67, 70, or 76 mm. The digitization of the Fulmar data notebooks was started in the late 1990s and finished in this study.
The data document the results of several microbe bioassays performed by the USGS on Phragmites australis plants, including those performed on mature leaves, seedlings, and dead leaf tissues exploration of the literature to find accounts of microbes associated with Phragmites worldwide. For the bioassays, we prepared 162 pure cultures isolated from Phragmites plants in North America along the east coast, Florida, the Gulf of Mexico, and the Great Lakes area, 125 of which were from a previous study, and 38 represent new collections. The DNA sequences used to identify the 37 new collections are included. Microbes were isolated from plants collected from 2015-2018. We performed assays using both North American plant...
These are the data sets in machine readable files from a quantitative dye tracer test conducted at Langle Spring November 13-December 2, 2017 as part of the USGS training class, GW2227 Advanced Field Methods in Karst Terrains, held at the Savoy Experimental Watershed, Savoy Arkansas. Langle Spring is NWIS site 71948218, latitude 36.11896886, longitude -94.34548871. One pound of RhodamineWT dye was injected into a sinking stream at latitude 36.116772 longitude -94.341883 NAD83 on November 13, 2017 at 22:50. The data sets include original fluorimeter data logger files from Langle and Copperhead Springs, Laboratory Sectra-fluorometer files from standards and grab samples, and processed input and output files from the...
This data set includes results for hormone and pharmaceutical compounds analyzed in environmental and quality-control samples collected by the USGS National Water-Quality Assessment Project during 2013 through 2015 for a study of groundwater resources used for drinking-water supply across the United States. Hormone and pharmaceutical results are provided for environmental samples collected at 1,120 wells or springs; selected ancillary data, such as principal aquifer, well depth, and land-use information also are provided for the sampled sites. The types of quality-control samples included in this data set are blanks, matrix spikes, and replicates collected at field sites or field offices. Included in this data...
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Cycle 3,
Drinking water,
Environmental Health,
Groundwater,
Hormones,
These raster data represent the results of a case study in Arizona on how vertebrate richness metrics can be used with existing state and federal guidance in wind and solar energy facility siting. Each of the four geodatabases (see Cross References) contain eight native terrestrial wildlife group models in Arizona: 1) all vertebrates, 2) amphibians, 3) reptiles, 4) birds, 5) mammals, 6) bats, 7) raptors and 8) long-distant migratory birds. An XML workbook is included that lists all terrestrial native vertebrate species in Arizona which cross-walks these species to the name of the National Gap Analysis Project species distribution model.
Water-quality data for groundwater samples collected from 4,824 sites between 1991 through 2018, and ancillary data and information on sampled wells and principal aquifers, were used to assess the occurrence and distribution of strontium in U.S. groundwater from 32 principal aquifers. This data release includes one tab-delimited text file detailing these data. Table: Chemical data from the U.S. Geological Survey National Water Information System and ancillary data considered for assessment of strontium concentration in U.S. groundwater.
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Hydrology,
NAWQA,
USGS Science Data Catalog (SDC),
Water Quality,
cycle 3,
Solid organic matter (OM) in sedimentary rocks produces petroleum and solid bitumen when it undergoes thermal maturation. The solid OM is a 'geomacromolecule', usually representing a mixture of various organisms with distinct biogenic origins, and can have high heterogeneity in composition. Programmed pyrolysis is a common conventional method to reveal bulk geochemical characteristics of the dominant OM while detailed organic petrography is required to reveal information about the biogenic origin of contributing macerals. Despite advantages of programmed pyrolysis, it cannot provide information about the heterogeneity of chemical compositions present in the individual OM types. Therefore, other analytical techniques...
Zebra and quagga mussel veligers were exposed to eleven distinct cultures (isolates) of cyanobacteria representing Anabaena, Aphanizomenon, Dolichospermum, Microcystis, and Planktothrix species and the cyanotoxin microcystin to determine the lethality of cyanobacteria on dreissenid veligers. Six-day laboratory bioassays were performed in microplates using dreissenid veligers collected from the Detroit River, Michigan, USA. Veligers were exposed to increasing concentrations of cyanobacteria and microcystin using the green algae Chlorella minutissima as a control. Raw data were fit to dose response curves formulated from a Probit model to calculate LC50 values. This data release presents the raw data summarized and...
These data consist of a multi-trophic, day vs. night, nearshore to offshore transect approach for data collection for this Cooperative Science and Monitoring Initiative effort at two northwestern Lake Huron sites near Hammond Bay and Thunder Bay, Michigan. Zooplankton and Mysis samples were collected monthly from April-October while benthos and prey fish samples were collected seasonally during Spring, Summer, and Fall. Invertebrate taxa (zooplankton, Mysis, benthic macroinvertebrates) were identified, enumerated, and measured using a dissecting microscope. Diet items of the prey fish were processed similarly to the other samples in terms of taxonomy. These data were used to calculate densities of fish prey items...
Data used to test a video monitoring and computational system for estimating juvenile fish abundance
We developed and tested neural network-based models to recognize and count emigrating juvenile river herring in continuous video. Continuous video was collected from an underwater camera installed at Great Herring Pond in Bourne, Massachusetts (USA) between June and November 2017. Our algorithm extracts video frames to assess presence/absence of fish and count numbers of fish emigrating. We used extracted video frames to assess model performance. Provided datasets include information about extracted frames that were used for model assessment. This data release includes four datasets that were used to test model performance and select the best fitting model. (1) The “Model Evaluation Dataset” includes count and presence/absence...
Categories: Data;
Tags: Ecology,
New England, Massachusetts, Cape Cod,
USGS Science Data Catalog (SDC),
biota
Note: This data release has been superseded, available here: https://doi.org/10.5066/P9MYL7WJ This data release contains processed high-resolution multichannel sparker seismic-reflection (MCS) data that were collected aboard Humboldt State University’s R/V Coral Sea in October of 2018 on U.S. Geological Survey cruise 2018-658-FA on the shelf and slope between Cape Blanco, Oregon, and Cape Mendocino, California. MCS data were collected to characterize quaternary deformation and sediment dynamics along the southern Cascadia margin.
The U.S. Geological Survey (USGS) developed a systematic, quantitative approach to prioritize candidate basins that can support the assessment and forecasting objectives of the major USGS water science programs. Candidate basins were the level-4 hydrologic units (HUC4) with some of the smaller HUC4s being combined (hereafter referred to as modified HUC4 basins). Candidate basins for the contiguous United States (CONUS) were grouped into 18 hydrologic regions. Thirty-three geospatial variables representing land use, climate change, water use, water-balance components, streamflow alteration, fire risk, and ecosystem sensitivity were initially considered to assist in ranking candidate basins for study. The two highest...
Categories: Data;
Tags: Climatology,
Ecology,
Hydrology,
Integrated Water Science Basins,
Land Use Change,
This data set contains shoreline rate of change statistics for New York State coastal wetlands. Analysis was performed using the Digital Shoreline Analysis System (DSAS), created by U.S. Geological Survey, version 5.0, an extension for ArcMap. A reference baseline was used as the originating point for orthogonal transects cast by the DSAS software. The transects intersect each polyline vector shoreline establishing intersection measurement points, which were then used to calculate the rates of change. End-point rates, calculated by dividing the distance of shoreline movement by the time elapsed between the oldest and the most recent shoreline, were generated for wetlands where fewer than three historic shorelines...
Categories: Data;
Types: ArcGIS REST Map Service,
ArcGIS Service Definition,
Downloadable,
Map Service;
Tags: Digital Shoreline Analysis System,
End-Point Rate,
Geography,
Geomorphology,
Great South Bay,
Macroinvertebrate samples were collected from streams tributary to Honnedaga Lake and from the Middle Branch of the Black River during 2012-2016 and analyzed for methylmercury concentrations and for stable isotope ratios of nitrogen and carbon. Macroinvertebrates were identified in the field, and the level of taxonomic resolution varied from order to species; most taxa were identified to the family level. Specimens were field-processed into composite samples, field-frozen, and submitted to the mercury laboratory for freeze-drying and analysis. Subsamples were then submitted to the stable isotope laboratory for analysis of nitrogen and carbon isotope ratios. This database contains the resulting data and associated...
Categories: Data;
Types: Map Service,
OGC WFS Layer,
OGC WMS Layer,
OGC WMS Service;
Tags: Ambient Monitoring,
Aquatic Biology,
Aquatic Community Health,
Ecosystem Health,
Environmental Health,
In October and November 2016-2017, transient electromagnetic (TEM) data, also called time domain electromagnetic (TDEM) surveys, were acquired at 120 locations in the Genesee Valley, Livingston County, New York, in order to characterize the subsurface resistivity structure in support of a U.S. Geological Survey groundwater investigation. The TEM data were collected as part of a project to evaluate geophysical methods to characterize the valley-fill sediments, underlying bedrock, and salinity of the subsurface. TEM data were collected using an ABEM WalkTEM unit (acquisition software V 1.1.0 and newer) using two transmitter loop (Tx) sizes, 100 by 100 meter square and 40 by 40 meters square, a center-loop receiver...
Categories: Data;
Tags: Aquifer Mapping,
Electromagnetic surveying,
Genesee River Valley,
Geophysics,
Geophysics,
|
|
