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Agricultural, Geographic and Population data for Counties in the Contiguous United States

Entry ID: EOSWEBSTER_US_County_Data

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Summary

Abstract: Annual crop data from 1972 to 1998 are now available on
EOS-WEBSTER. These data are county-based acreage, production, and
yield estimates published by the National Agricultural Statistics
Service. We also provide county level livestock, geography,
agricultural management, and soil properties derived from datasets
from the early 1990s.

The National ...

Related URL

Link: View Related Information

Description: EOS-WEBSTER Earth Science Information Partner (ESIP) provides
terrestrial ecosystem research data via a web-based search, subset and order
system.

Geographic Coverage

(Click for Interactive Map)

Spatial coordinates

N: 50.0

S: 26.0

E: -66.0

W: -124.0

Temporal Coverage

Start Date: 1972-01-01

Stop Date: 1998-12-31

Location Keywords

CONTINENT > NORTH AMERICA > UNITED STATES OF AMERICA

CONTINENT > NORTH AMERICA

Science Keywords

AGRICULTURE > AGRICULTURAL CHEMICALS > FERTILIZERS

AGRICULTURE > AGRICULTURAL PLANT SCIENCE > CROP/PLANT YIELDS

ISO Topic Category

GEOSCIENTIFIC INFORMATION

OCEANS

Platform

SHIPS

Instrument

GRAB SAMPLERS

SEDIMENT CORERS

GAS CHROMATOGRAPHS

MASS SPECTROMETERS

Quality Data quality is good for all sediment records.

Tin-wrapped samples are loaded into carousels with 49 samples in each tray and 3 trays making up a full run of 147 samples. The carousels are placed on an AS200 autosampler that drops a sample in response to a pulse of compressed air. Gases are swept through the columns and GC by an approximately 100 ml min-1 flow of high purity ... helium. The sample dropper uses a sliding port that maintains the approximately 1 atmosphere pressure of the helium required to force the gases through the columns and GC.
The autosampler sits on top of a Carlo Erba CE1110 CHN-S analyser containing the two furnaces, the scrubber and the GC (Gas Chromatograph). After the GC in the gas stream sits a TCD (Thermal Conductivity Detector) which is used to measure peak area when the machine is used as an elemental analyser. The samples are dropped into the left-hand furnace which is the oxidising furnace and is maintained at 1050 degrees C. It consists of a silica glass tube filled with chromium oxide to the midpoint, with cobaltous silver oxide under it. A tube takes the carrier gas from the bottom of this reactor to the second, reducing furnace tube which the mixed gases flow up through. The second silica glass tube is filled with metallic copper pellets and is kept at 660 degrees C. The gases flow out of the top of this tube and through a scrubber filled with magnesium perchlorate to absorb all water vapour. The dried gases then pass through a packed GC consisting of a 1/4" stainless steel tube with Porapak QS 50-80 mesh. This is held at about 25 degrees C. Nitrogen gas exits from the GC, followed by carbon dioxide after about one minute. These flow to an open split where they are sucked into the mass spectrometer through a 75 micro silica capillary.
The gas pulses, still mixed with the helium carrier, flow into the Fisons Isochrom CF-IRMS (Continuous-flow Isotope Ratio Mass Spectrometer) where their isotopic compositions are determined.

Surface sediment samples were analysed to determine the gravel, sand and mud content by washing through 2 mm and 63 micron sieves. The less than 2 mm fraction was also analysed for laser particle size. Carbonate content was determined on the bulk material as well as the mud and sand fractions using the carbonate bomb method (Muller and Gastner, 1971). The carbonate content of the gravel fraction was determined by visual analysis. The biogenic silica content of the bulk sediment was measured based on the method of Mortlock and Froelich (1989). Muller, G., Gastner, M., 1971. The "Karbonat-Bombe," a simple device for the determination of the carbonate content in sediments, soils and other materials. Neues Jahrbuch fur Mineralogie, Monatshefte 10, 466-469. Mortlock, R.A., Froelich, P.N., 1989. A simple method for the rapid determination of biogenic opal in pelagic marine sediments. Deep Sea Research 36, 1415-1426.

Access Constraints These data are publicly available for download from the provided URLs. Contact the investigators for permission to use the data.

The dataset contains two excel spreadsheets detailing the sediment isotopes and the grainsize compositions, plus a pdf which provides further information about the laser grainsize data.

Furthermore a link to Geoscience Australia's Marine Sediments Database is included. Data can also be found here.

Use Constraints This data set conforms to the PICCCBY Attribution License
(http://creativecommons.org/licenses/by/3.0/).

Please follow instructions listed in the citation reference provided at http://data.aad.gov.au/aadc/metadata/citation.cfm?entry_id=CEAMARC-... when using these data.

Ancillary Keywords

sediment samples

surface sediment

Data Set Progress

COMPLETE

Data Center

Australian Antarctic Data Centre, Australia

Data Center URL: http://data.aad.gov.au

Data Center Personnel
Name: DATA OFFICER AADC Phone: +61 3 6232 3244 Fax: +61 3 6232 3351 Email: metadata at aad.gov.au Contact Address: Australian Antarctic Division 203 Channel Highway City: Kingston Province or State: Tasmania Postal Code: 7050 Country: Australia