Point Shapefile of Electrical Conductance Geoprobe Locations Collected in August, 2005 in the Nauset Marsh Area of Cape Cod, Massachusetts

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Frequently-anticipated questions:

What does this data set describe?

Title:
Point Shapefile of Electrical Conductance Geoprobe Locations Collected in August, 2005 in the Nauset Marsh Area of Cape Cod, Massachusetts
Abstract:
In order to test hypotheses about groundwater flow under and into estuaries and the Atlantic Ocean, geophysical surveys, geophysical probing, submarine groundwater sampling, and sediment coring were conducted by U.S. Geological Survey (USGS) scientists at Cape Cod National Seashore (CCNS) from 2004 through 2006. Coastal resource managers at CCNS and elsewhere are concerned about nutrients that are entering coastal waters via submarine groundwater discharge, which are contributing to eutrophication and harmful algal blooms. The research carried out as part of the study described here was designed, in part, to help refine assumptions required by earlier versions of models about the nature of submarine groundwater flow and discharge at CCNS. This study was conducted in four phases, with a variety of field techniques and equipment employed in each phase. Phase 1 consisted of continuous resistivity profiling (CRP) surveys of the entire study area conducted in 2004. Phase 2 consisted of CRP ground-truthing via resistivity probe measurements and submarine groundwater sampling from hydraulically-drive piezometers using a barge in the Salt Pond/Nauset Marsh area in 2005. Phase 3 consisted of supplemental detailed CRP surveys in the Salt Pond/Nauset Marsh area in 2006. Finally, Phase 4 consisted of sediment coring and porewater extraction in the Salt Pond/Nauset Marsh area later in 2006 to supplement the 2005 sampling.
  1. How should this data set be cited?

    Bratton, John F. , 2008, Point Shapefile of Electrical Conductance Geoprobe Locations Collected in August, 2005 in the Nauset Marsh Area of Cape Cod, Massachusetts: Open-File Report 2006-1169, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, MA.

    Online Links:

    This is part of the following larger work.

    Cross, VeeAnn A. , Bratton, John F. , Crusius, John, Colman, John A. , and McCobb, Timothy D. , 2008, Submarine Hydrogeological Data from Cape Cod National Seashore: Open-File Report 2006-1169, U.S. Geological Survey, Coastal and Marine Geology Program, Woods Hole Science Center, Woods Hole, MA.

    Online Links:

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -69.971573
    East_Bounding_Coordinate: -69.965783
    North_Bounding_Coordinate: 41.835978
    South_Bounding_Coordinate: 41.832088

  3. What does it look like?

  4. Does the data set describe conditions during a particular time period?

    Beginning_Date: 22-Aug-2005
    Ending_Date: 23-Aug-2005
    Currentness_Reference: ground condition

  5. What is the general form of this data set?

    Geospatial_Data_Presentation_Form: vector digital data

  6. How does the data set represent geographic features?

    1. How are geographic features stored in the data set?

      This is a Vector data set. It contains the following vector data types (SDTS terminology):

      • Entity point (5)

    2. What coordinate system is used to represent geographic features?

      Horizontal positions are specified in geographic coordinates, that is, latitude and longitude. Latitudes are given to the nearest 0.000000. Longitudes are given to the nearest 0.000000. Latitude and longitude values are specified in Decimal degrees.

      The horizontal datum used is North American Datum of 1983.
      The ellipsoid used is Geodetic Reference System 80.
      The semi-major axis of the ellipsoid used is 6378137.000000.
      The flattening of the ellipsoid used is 1/298.257222.

  7. How does the data set describe geographic features?

    geoprobeloc_2005

    FID
    Internal feature number. (Source: ESRI)

    Sequential unique whole numbers that are automatically generated.

    Shape
    Feature geometry. (Source: ESRI)

    Coordinates defining the features.

    SITE
    Name assigned to the geoprobe drill location. (Source: Chief scientist.)

    character set

    LATITUDE
    Latitude position of the data point referenced to NAD27. (Source: Recorded value as acquired by a GPS.)

    Range of values
    Minimum:41.83056
    Maximum:41.83587
    Units:decimal degrees

    LONGITUDE
    Longitude position of the data point referenced to NAD27. (Source: Recorded value as acquired by a GPS.)

    Range of values
    Minimum:-69.97211
    Maximum:-69.96347
    Units:decimal degrees

    ERROR
    Approximate navigational location error in meters. (Source: Field scientist.)

    numbers in character field

    COMMENT
    Brief description of work at drilling location. (Source: Field scientist.)

    character set

    COLDATE
    Date of drilling. (Source: Field scientist.)

    Date character set.

    long_nad83
    Longitude position of the data point referenced to NAD83. (Source: Calculated value.)

    Range of values
    Minimum:-69.971573
    Maximum:-69.965783
    Units:decimal degrees

    lat_nad83
    Latitude position of the data point referenced to NAD83. (Source: Calculated value.)

    Range of values
    Minimum:41.832088
    Maximum:41.835978
    Units:decimal degrees

    Entity_and_Attribute_Overview:
    A modified version of Geoprobe System's Direct Image Electrical Conductivity tool was used to make conductivity measurements in the sediment below the sediment water interface. A Wenner-array probe (Geoprobe SC200) was attached to a 25 mm-diameter probe rod. The probe was connected to the surface floating barge by a water-tight shielded cable. This probe consists of four contact rings; one pair carries a known current and another pair measures the resulting voltage through the formation. The probe and probe rod were advanced through the sediment by hand (when possible) or by automatic vibratory hammer at 30 cm intervals. Multiple measurements were made at each interval, and the average EC value was recorded.

Who produced the data set?

  1. Who are the originators of the data set? (may include formal authors, digital compilers, and editors)

  2. Who also contributed to the data set?

  3. To whom should users address questions about the data?

    John F. Bratton
    U.S. Geological Survey
    384 Woods Hole Rd.
    Woods Hole, MA 02543-1598

    (508) 548-8700 x2254 (voice)
    (508) 457-2310 (FAX)
    jbratton@usgs.gov

Why was the data set created?

This shapefile is used to provide the locations where electrical conductance (EC) probe profiling measurements were taken within the Cape Cod National Seashore in 2005.

How was the data set created?

  1. From what previous works were the data drawn?

  2. How were the data generated, processed, and modified?

    Date: 2005 (process 1 of 4)
    The GPS location and various other information was recorded by the chief scientist in a log book for each drilling site.

    Person who carried out this activity:

    John F. Bratton
    U.S. Geological Survey
    384 Woods Hole Rd.
    Woods Hole, MA 02543-1598

    (508) 548-8700 x2254 (voice)
    (508) 457-2310 (FAX)
    jbratton@usgs.gov

    Date: 2006 (process 2 of 4)
    This recorded information was reformatted and imported from a comma delimited text file and converted to a shapefile using ArcGIS 9.1. The original recorded positions were based on the NAD27 datum.

    Person who carried out this activity:

    VeeAnn A. Cross
    U.S. Geological Survey
    Marine Geologist
    384 Woods Hole Rd.
    Woods Hole, MA 02543-1598

    (508) 548-8700 x2251 (voice)
    (508) 457-2310 (FAX)
    vatnipp@usgs.gov

    Data sources used in this process:
    • drill_locations.txt

    Data sources produced in this process:

    • drill_locsnad27.shp

    Date: 2006 (process 3 of 4)
    The shapefile was projected to the NAD83 datum using ArcGIS 9.1.

    Person who carried out this activity:

    VeeAnn A. Cross
    U.S. Geological Survey
    Marine Geologist
    384 Woods Hole Rd.
    Woods Hole, MA 02543-1598

    (508) 548-8700 x2251 (voice)
    (508) 457-2310 (FAX)
    vatnipp@usgs.gov

    Data sources used in this process:
    • drill_locsnad27.shp

    Data sources produced in this process:

    • geoprobeloc_2005.shp

    Date: 2007 (process 4 of 4)
    The new latitude and longitude values, based on NAD83, were added to the shapefile using XTools Pro version 4.0 within ArcGIS 9.1.

    Person who carried out this activity:

    VeeAnn A. Cross
    U.S. Geological Survey
    Marine Geologist
    384 Woods Hole Rd.
    Woods Hole, MA 02543-1598

    (508) 548-8700 x2251 (voice)
    (508) 457-2310 (FAX)
    vatnipp@usgs.gov

    Data sources used in this process:
    • geoprobeloc_2005.shp

    Data sources produced in this process:

    • geoprobeloc_2005.shp

  3. What similar or related data should the user be aware of?

How reliable are the data; what problems remain in the data set?

  1. How well have the observations been checked?

  2. How accurate are the geographic locations?

  3. How accurate are the heights or depths?

  4. Where are the gaps in the data? What is missing?

    This dataset is complete inasmuch as the location for all the geprobe locations are represented.

  5. How consistent are the relationships among the observations, including topology?

    No additional checks for topological consistency other than visual inspection were performed on the data.

How can someone get a copy of the data set?

Are there legal restrictions on access or use of the data?

Access_Constraints: None.
Use_Constraints:
The U.S. Geological Survey must be referenced as the originator of the dataset in any future products or research derived from these data.

  1. Who distributes the data set? (Distributor 1 of 1)

    John F. Bratton
    U.S. Geological Survey
    384 Woods Hole Rd.
    Woods Hole, MA 02543-1598

    (508) 548-8700 x2254 (voice)
    (508) 457-2310 (FAX)
    jbratton@usgs.gov

  2. What's the catalog number I need to order this data set?

    Downloadable Data

  3. What legal disclaimers am I supposed to read?

    Neither the U.S. Government, the Department of the Interior, nor the USGS, nor any of their employees, contractors, or subcontractors, make any warranty, express or implied, nor assume any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, nor represent that its use would not infringe on privately owned rights. The act of distribution shall not constitute any such warranty, and no responsibility is assumed by the USGS in the use of these data or related materials. Any use of trade, product, or firm names is for descriptive purposes only and does not imply endorsement by the U.S. Government.

  4. How can I download or order the data?

  5. What hardware or software do I need in order to use the data set?

    These data are available in Environmental Systems Research Institute (ESRI) shapefile format. The user must have ArcGIS or ArcView 3.0 or greater software to read and process the data file. In lieu of ArcView or ArcGIS, the user may utilize another GIS application package capable of importing the data. A free data viewer, ArcExplorer, capable of displaying the data is available from ESRI at www.esri.com.

Who wrote the metadata?

Dates:
Last modified: 25-Feb-2008
Metadata author:
VeeAnn A. Cross
U.S. Geological Survey
Marine Geologist
384 Woods Hole Rd.
Woods Hole, MA 02543-1598

(508) 548-8700 x2251 (voice)
(508) 457-2310 (FAX)
vatnipp@usgs.gov

Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)
Metadata extensions used:

Generated by mp version 2.8.6 on Tue Jul 08 11:20:54 2008