This data set consists of a digital glacial geology map of the Toolik and upper Kuparuk River region, Alaska, USA. The map covers a 740 km² area on Alaska's North Slope, in the northern foothills of the Brooks Range. The map contains polygon and line features, annotation, and legends and is distributed as an ArcInfo GIS interchange (.e00) file or shapefiles. The data set describes substrate only and does not include topographic, hydrographic, or cultural features.
The map is designed to be used in conjunction with the report Glacial Geology of Toolik Lake and the Upper Kuparuk River region by Thomas D. Hamilton. To access this report in PDF format, please visit the Circumpolar Arctic Geobotanical Atlas, Upper Kuparuk Maps site. The site also provides printable versions of the glacial geology map.
This research was funded by the Arctic System Sciences (ARCSS) Program, grant number OPP-9908829.
Data are available for ordering through NCAR.
Walker, D.A., T.D. Hamilton, A.W. Balser, and J.A. Anderson. 2003. Glacial Geology Map of the Toolik Lake and Upper Kuparuk River Region, Alaska. Boulder, CO: National Center for Atmospheric Research, ARCSS Data Archive.
|Data format||ArcInfo interchange file and shapefiles|
|Spatial coverage||Toolik and upper Kuparuk River region, Alaska, from 68.48º N to 68.74º N, and 149.02º W to 149.67º W|
|Temporal coverage||The map shows features that are approximately 350,000 years before present (ybp) to present.|
|File size||1.5 MB (ArcInfo export file); 625KB to 918 KB (shapefiles)|
|Parameter(s)||Glacial geologic unit, glacial landforms/processes, landscape pattern, glaciation, sedimentation|
The data are available as an ArcInfo interchange file that imports as a coverage, and shapefiles, as described below.
Complete metadata are also available.
Additionally, image files representing these data are available.
The data file sizes are as follows:
The bounding coordinates of the map are as follows:
Southernmost latitude: 68.48º N
Northernmost latitude: 68.74º N
Westernmost longitude: 149.67º W
Easternmost longitude: 149.02º W
Projection: Albers Equal Area
First Standard Parallel: 55º 0' 0" N
Second Standard Parallel: 65º 0' 0" N
Central Meridian: 154º 0' 0" W
Latitude of Origin: 50º 0' 0" N
False Easting: 0.0
False Northing: 0.0
The resolution of the map is 50 m, which represents the smallest discernable polygon.
Geographic features are represented as polygons (glacial geology units), and lines (drainage channels, divide crossings, and unit boundaries). The keys to the polycode and linecode attributes (coverage and shapefile) appear in the Entity and Attribute Information section of the metadata files.
The attributes in the "geolmap_poly" shapefile correspond to the entity GEOLMAP.PAT, and the attributes in the "geolmap_line" shapefile correspond to the entity GEOLMAP.AAT.
The following image, "25kggeol.jpg," is a JPEG version of the glacial geology map. The resolution is lower than the publication-quality TIFF version ("geolmap_pub.tif.gz"). This file is also available for ordering through NCAR.
Glacial geology map of the Toolik Lake and Upper Kuparuk River region, Alaska. Image by Dr. Donald Walker, University of Alaska Fairbanks.
The data are estimated to have positional accuracy to within 50 m and were created with the greatest spatial accuracy possible; however, they are not guaranteed to conform to national map accuracy standards for maps at 1:25,000 scale.
Attribute accuracy is considered 100%, except for POLYCODES that contain a "?" after the code. These are presumed accurate, but lack field confirmation.
Data are available through NCAR.
To use the interchange file, users must have ArcInfo GIS software. Shapefiles can be used with GIS or image processing software, such as ENVI, PCI, or ERDAS.
Data were developed from a combination of airphoto interpretation and in situ measurements. The source photos were 100% cloud free.
The airphoto was an orthorectified, panchromatic hardcopy at 1:25,000 scale.
Polygons and lines were digitized manually from the airphoto, and attributes were added based on field reconnaissance.
Hamilton, T.D. 2002. Glacial Geology of the Toolik Lake and Upper Kuparuk River Region. Edited by D.A. Walker. Biological Papers of the University of Alaska. University of Alaska Fairbanks, Institute of Arctic Biology, Fairbanks, AK. ISSN: 00568-8604. http://www.geobotany.uaf.edu/arcticgeobot/support_docs_4_maps/2002_hamilton.pdf. 14 October 2003.
Hamilton, T.D. 1978. Surficial geologic map of the Philip Smith Mountains quadrangle, Alaska. U.S. Geological Survey Miscellaneous Field Studies Map MF-879-A. Scale 1:25,000.
Circumpolar Arctic Geobotanical Atlas, Upper Kuparuk Maps. http://www.geobotany.uaf.edu/arcticgeobot/ukggeol.html. 14 October 2003.