Unpublished Digital Geologic Map of Tutuila, American Samoa (NPS, GRD, GRI, NPSA, TUTU digital map) adapted from Geological Society of America Bulletin maps by Wingert, (compiler) and Pereira (prefacer) (1981)

Metadata also available as

Frequently-anticipated questions:

What does this data set describe?
    Title:
    Unpublished Digital Geologic Map of Tutuila, American Samoa (NPS, GRD, GRI, NPSA, TUTU digital map) adapted from Geological Society of America Bulletin maps by Wingert, (compiler) and Pereira (prefacer) (1981)
    Abstract:
    The Unpublished Digital Geologic Map of Tutuila, American Samoa is composed of GIS data layers and GIS tables in a 10.1 file geodatabase (tutu_geology.gdb), a 10.1 ArcMap (.MXD) map document (tutu_geology.mxd), individual 10.1 layer (.LYR) files for each GIS data layer, an ancillary map information (.PDF) document (npsa_geology.pdf) which contains source map unit descriptions, as well as other source map text, figures and tables, metadata in FGDC text (.TXT) and FAQ (.HTML) formats, and a GIS readme file (tutu_gis_readme.pdf). Please read the tutu_gis_readme.pdf for information pertaining to the proper extraction of the file geodatabase and other map files. To request GIS data in ESRI 10.1 shapefile format contact Stephanie O’Meara (stephanie.omeara@colostate.edu; see contact information below). The data were completed as a component of the Geologic Resources Inventory (GRI) program, a National Park Service (NPS) Inventory and Monitoring (I&M) Division funded program that is administered by the NPS Geologic Resources Division (GRD). Source geologic maps and data used to complete this GRI digital dataset were provided by the following: Geological Society of America. Detailed information concerning the sources used and their contribution the GRI product are listed in the Source Citation section(s) of this metadata record (tutu_metadata_faq.html; available at <http://nrdata.nps.gov/geology/gri_data/gis/npsa/tutu_metadata_faq.html>). Users of this data are cautioned about the locational accuracy of features within this dataset. Based on the source map scale of 1:24,000 and United States National Map Accuracy Standards features are within (horizontally) 12.2 meters or 40 feet of their actual location as presented by this dataset. Users of this data should thus not assume the location of features is exactly where they are portrayed in ArcGIS or other software used to display this dataset. All GIS and ancillary tables were produced as per the NPS GRI Geology-GIS Geodatabase Data Model v. 2.3. (available at: <http://science.nature.nps.gov/im/inventory/geology/GeologyGISDataModel.cfm>). The GIS data projection is defined as NAD83, UTM Zone 2N, however, its actually 2S (south). ArcGIS software doesn't allow for a 2S (south) definition for a NAD83 datum. No "north" parameters are a part of the spatial reference parameters, and all latitude values are negative. The data is within the area of interest of National Park of American Samoa.
    Supplemental_Information:
    The data layers (feature classes) that comprise the Unpublished Digital Geologic Map of Tutuila, American Samoa include: TUTUGLGA (Geologic Contacts), TUTUDKE (Linear Dikes), TUTUFLT (Faults), TUTUSEC (Geologic Cross Section Lines), TUTUVLF (Volcanic Line Features), TUTUATD (Geologic Attitude Observation Localities), TUTUVPF (Volcanic Point Features) and TUTUGLG (Geologic Units). There are three additional ancillary map components, the Geologic Unit Information (NPSAUNIT) Table, the Source Map Information (NPSAMAP) Table and the Map PDF Document (npsa_geology.pdf). Refer to the NPS GRI Geology-GIS Geodatabase Data Model v. 2.3 (available at: <http://science.nature.nps.gov/im/inventory/geology/GeologyGISDataModel.cfm>) for detailed data layer (feature class) and table specifications including attribute field parameters, definitions and domains, and implemented topology rules and relationship classes.

  1. How should this data set be cited?

    National Park Service (NPS) Geologic Resources Inventory (GRI) program, 20160329, Unpublished Digital Geologic Map of Tutuila, American Samoa (NPS, GRD, GRI, NPSA, TUTU digital map) adapted from Geological Society of America Bulletin maps by Wingert, (compiler) and Pereira (prefacer) (1981).

    Online Links:

  2. What geographic area does the data set cover?

    West_Bounding_Coordinate: -170.851604645247
    East_Bounding_Coordinate: -170.541647840632
    North_Bounding_Coordinate: -14.2242922706203
    South_Bounding_Coordinate: -14.3795165818435

  3. What does it look like?

    Not applicable
    No browse graphic provided

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

    Calendar_Date: 29-Mar-2016
    Currentness_Reference: ground condition

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

    Geospatial_Data_Presentation_Form: map

  6. How does the data set represent geographic features?

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

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

      Grid_Coordinate_System_Name: Universal Transverse Mercator
      Universal_Transverse_Mercator:
      UTM_Zone_Number: 2
      Transverse_Mercator:
      Scale_Factor_at_Central_Meridian: 0.999600
      Longitude_of_Central_Meridian: -171.0
      Latitude_of_Projection_Origin: 0.000000
      False_Easting: 500000.000000
      False_Northing: 0.000000

      Planar coordinates are encoded using coordinate pair
      Abscissae (x-coordinates) are specified to the nearest 0.000007
      Ordinates (y-coordinates) are specified to the nearest 0.000007
      Planar coordinates are specified in meters

      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?

    Entity_and_Attribute_Overview:
    Refer to the NPS GRI Geology-GIS Geodatabase Data Model v. 2.3 (available at: <http://science.nature.nps.gov/im/inventory/geology/GeologyGISDataModel.cfm>) for detailed feature class and table attribute field parameters, definitions and domains, and implemented relationship classes, as well as for implemented feature class topology rules.
    Entity_and_Attribute_Detail_Citation:
    NPS GRI Geology-GIS Geodatabase Data Model v. 2.3. (available at: <http://science.nature.nps.gov/im/inventory/geology/GeologyGISDataModel.cfm>)

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?

    Stephanie O'Meara and James R. Chappell (Colorado State University)

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

    Stephanie O'Meara
    Colorado State University
    Research Associate, Geologist/GIS Specialist/Data Manager
    1201 Oak Ridge Drive, Suite 200
    Fort Collins, Colorado 80525
    USA

    (970) 491-6655 (voice)
    stephanie.omeara@colostate.edu

    Hours_of_Service: 9:00 a.m. to 5:00 p.m. (MST), Monday - Friday

Why was the data set created?
The data are intended to assist NPS personnel in the protection and management of National Park of American Samoa.

How was the data set created?
  1. From what previous works were the data drawn?

    Geological Society of America Bulletin Volume 55 (source 1 of 3)
    Wingert, Everett A .(compiler); Pereira, Joseph , 1981, A Coastal Zone Management Atlas of American Samoa: Page 15, Geology: Eastern Tutuila: Geological Society of America Bulletin Volume 55, Geological Society of America, Boulder, Colorado.

    Type_of_Source_Media: paper
    Source_Scale_Denominator: 24000
    Source_Contribution:
    Geologic features present on the source map were digitized using a .TIF image of the paper map that was scanned at 300dpi and georeferenced in NAD83 UTM. Although the source map was published at 1:24,000 scale it appears shoreline was generalized and likely derived from a smaller scale (approximately 1:56,000) source map. The source map scan was also used to attribute features, as well as to check (QC) line quality, both positionally and spatially, and feature attribution. Ancillary source map text, including unit descriptions, and graphics, if present, were captured, formatted and added to the ancillary map PDF document. See the Process Step section for additional information.

    Geological Society of America Bulletin Volume 55 (source 2 of 3)
    Wingert, Everett A .(compiler); Pereira, Joseph , 1981, A Coastal Zone Management Atlas of American Samoa: Page 14, Geology: Central Tutuila: Geological Society of America Bulletin Volume 55, Geological Society of America, Boulder, Colorado.

    Type_of_Source_Media: paper
    Source_Scale_Denominator: 24000
    Source_Contribution:
    Geologic features present on the source map were digitized using a .TIF image of the paper map that was scanned at 300dpi and georeferenced in NAD83 UTM. Although the source map was published at 1:24,000 scale it appears shoreline was generalized and likely derived from a smaller scale (approximately 1:56,000) source map. The source map scan was also used to attribute features, as well as to check (QC) line quality, both positionally and spatially, and feature attribution. Ancillary source map text, including unit descriptions, and graphics, if present, were captured, formatted and added to the ancillary map PDF document. See the Process Step section for additional information.

    Geological Society of America Bulletin Volume 55 (source 3 of 3)
    Wingert, Everett A .(compiler); Pereira, Joseph , 1981, A Coastal Zone Management Atlas of American Samoa: Page 13, Geology: Western Tutuila: Geological Society of America Bulletin Volume 55, Geological Society of America, Boulder, Colorado.

    Type_of_Source_Media: paper
    Source_Scale_Denominator: 24000
    Source_Contribution:
    Geologic features present on the source map were digitized using a .TIF image of the paper map that was scanned at 300dpi and georeferenced in NAD83 UTM. Although the source map was published at 1:24,000 scale it appears shoreline was generalized and likely derived from a smaller scale (approximately 1:56,000) source map. The source map scan was also used to attribute features, as well as to check (QC) line quality, both positionally and spatially, and feature attribution. Ancillary source map text, including unit descriptions, and graphics, if present, were captured, formatted and added to the ancillary map PDF document. See the Process Step section for additional information.

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

    Date: 29-Mar-2016 (process 1 of 1)
    1.) GIS features were digitized from a TIF image of the source map scanned at 300dpi and georeferenced in NAD83 UTM coordinates. Georeferencing was checked using 2001 U.S. topographic maps with correct longitude and latitude tics and ESRI 2016 world imagery. See the Source Information Contribution section(s) for specific source map details. Geology features were digitized into a data model compliant geodatabase. For details on the GRI data model see the NPS GRI Geology-GIS Geodatabase Data Model v. 2.1 (available at: <http://science.nature.nps.gov/im/inventory/geology/GeologyGISDataModel.cfm>). 2.) Line quality was checked against the source scan to ensure that GIS features were represented accurately, both positionally and spatially. 3.) Feature attribution was derived using the source map. 4.) Data Model topology rules were validated for all features and any topology errors corrected. 5.) Quality control (QC) consisting of a visual check of the data against its source, as well as running a GRI developed ArcObjects tool to check for GRI data model validation and feature-related consistency, was conducted. 6.) The UNIT and MAP tables were populated and checked against the source (s). Relationship classes were also added and used to ensure attribution consistency between feature class and table attribution. 7.) Feature symbology was produced for all feature classes. An attempt was made to best match symbology to its source map, however, in some cases feature symbology maybe slightly modified, primarily based on the limitations of the ArcGIS geology style. In some cases, however, symbology may have been modified to reconcile differences from multiple sources. 8.) GIS feature classes were exported from the geodatabase to shapefile (SHP) format, and GIS tables exported to DBASEIV (DBF) format. Layer (LYR) files were also exported. 9.) The ancillary map information PDF document, see the Supplemental Information section for additional information, was produced from textual information and figures present on the source map(s) and/or in digital data files. If applicable, source map images were produced at 150dpi or greater resolution and optical character recognition (OCR) software was used to produce text from source map text. The text, source map images and other ancillary source map information were added to a Help & Manual (.HMXZ) template file. The HMXZ file was then compiled to produce the ancillary map PDF document. Any compilation errors were checked and corrected and the document was reviewed for content, usability and grammatical errors.

    Person who carried out this activity:

    Stephanie O'Meara
    Colorado State University
    Research Associate, Geologist/GIS Specialist/Data Manager
    1201 Oak Ridge Drive, Suite 200
    Fort Collins, Colorado 80525-5589
    USA

    (970) 491-6655 (voice)
    stephanie.omeara@colostate.edu

    Hours_of_Service: 9:00 a.m. to 5:00 p.m. (MST), Monday - Friday
    Data sources used in this process:
    • Geological Society of America Bulletin Volume 55

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

    National Park Service Geologic Resources Inventory (GRI) program, 20160329, Metadata for the Unpublished Digital Geologic Map of Tutuila, American Samoa (NPS, GRD, GRI, NPSA, TUTU digital map).

    Online Links:

How reliable are the data; what problems remain in the data set?
  1. How well have the observations been checked?

    Feature and table attribution was derived and checked with the source map(s). Attribution was checked (QCd) for errors. Users of this data are advised to FULLY and CAREFULLY READ the "DISTRIBUTION LIABILITY" section of this metadata before using the data.

  2. How accurate are the geographic locations?

    Data was digitized from a georeferenced source map .TIF image(s) (300dpi). Users of this data are cautioned about the locational accuracy of features within this dataset. Based on the source map scale and United States National Map Accuracy Standards features are within (horizontally) 12.2 meters or 40 feet of their actual location as presented by this dataset. However, for shoreline, derived from the source map, it does appear that this is more generalized than shoreline present on a typical 1:24,000 scale map. There is no mention on the source map of its base map date or scale, however, the source map states its primary source map scale was “approximately 1:63,000”. So, users should not assume shoreline is as accurate as 1:24,000 scale data. Users of this data should thus not assume the location of features is exactly where they portrayed are in ArcGIS or other software used to display this dataset. The maximum root mean square (RMS) horizontal accuracy of the georeferenced image as measured in ArcMap is 6 meters. The PRECISION of any Shapefile (.SHP) files is DOUBLE. Coordinate tics on the georeferenced (registered and rectified) source map image(s) was checked against control points that had the exact specified coordinates of the tic. The direct distance between the image tic and its control point were measured. All measured distances were less than 50% of the required distance to meet National Map Accuracy Standards (1/50th of an inch for maps at 1:20,000 scale and smaller). Features was checked (QCd) after digitizing for positional accuracy errors using the georeferenced source map image. All shoreline has been attributed as “water/shoreline, approximate”.

  3. How accurate are the heights or depths?

    No vertical coordinates are present in this GRI digital dataset.

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

    All data is considered complete to the extent of the source map(s).

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

    GIS data in 10.1 file geodatabase format

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:
Not for use at scale greater than 1:24,000 (source map scale). Users of this data are cautioned about the locational accuracy of features within this dataset. Based on the source map scale and United States National Map Accuracy Standards features are within (horizontally) 12.2 meters or 40 feet of their actual location as presented by this dataset. However, for shoreline, derived from the source map, it does appear that this is more generalized than shoreline present on a typical 1:24,000 scale map. There is no mention on the source map of its base map date or scale, however, the source map states its primary source map scale was “approximately 1:56,000”. So, users should not assume shoreline is as accurate as the 1:24,000 scale geologic feature data. Users of this data should thus not assume the location of features is exactly where they are portrayed in ArcGIS or other software used to display this dataset.

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

    Stephanie O'Meara
    Colorado State University
    Research Associate, Geologist/GIS Specialist/Data Manager
    1201 Oak Ridge Drive, Suite 200
    Fort Collins, Colorado 80525
    USA

    (970) 491-6655 (voice)
    stephanie.omeara@colostate.edu

    Hours_of_Service: 8:00 a.m. to 4:00 p.m. (MST), Monday - Friday
    Contact_Instructions:
    GRI data are available at: <http://irma.nps.gov/App/Reference/Search>
  2. What's the catalog number I need to order this data set?

    GIS map data available in 10.1 file geodatabase format (in tutugdb.zip)

  3. What legal disclaimers am I supposed to read?

    The National Park Service shall not be held liable for improper or incorrect use of the data described and/or contained herein. These data and related graphics are not legal documents and are not intended to be used as such.

    The information contained in these data is dynamic and may change over time. The data are not better than the original sources from which they were derived. It is the responsibility of the data user to use the data appropriately and consistent within the limitations of geospatial data in general and these data in particular. The related graphics are intended to aid the data user in acquiring relevant data; it is not appropriate to use the related graphics as data.

    The National Park Service gives no warranty, expressed or implied, as to the accuracy, reliability, or completeness of these data. It is strongly recommended that these data are directly acquired from an NPS server and not indirectly through other sources which may have changed the data in some way. Although these data have been processed successfully on a computer system at the National Park Service, no warranty, expressed or implied is made regarding the utility of the data on another system or for general scientific purposes, nor shall the act of distribution constitute any such warranty. This disclaimer applies to both to individual use of the data and aggregate use with other data.

  4. How can I download or order the data?

Who wrote the metadata?
Dates:
Last modified: 29-Mar-2016

Metadata author:
Stephanie O'Meara
Colorado State University
Research Associate, Geologist/GIS Specialist/Data Manager
1201 Oak Ridge Drive, Suite 200
Fort Collins, Colorado 80525-5589
USA

(970) 491-6655 (voice)
stephanie.omeara@colostate.edu

Hours_of_Service: 9:00 a.m. to 5:00 p.m. (MST), Monday - Friday
Metadata standard:
FGDC Content Standards for Digital Geospatial Metadata (FGDC-STD-001-1998)

Metadata extensions used:

Generated by mp version 2.7.19 on Wed Mar 30 09:28:03 2016