Geologic Photos of Alaska: The Geologic Photos of Alaska database and application stores and displays images and image metadata, ensuring that photos and their descriptions are preserved over the long term. The web-based application displays photo locations as a point or polygon, depending on the accuracy of the location. A location "area" implies that the location is less well known. A comprehensive list of attributes and their parameters can be found in the data dictionary. FAQs about the application and the application's text- and map-based search functionality are documented at <http://maps.dggs.alaska.gov/photodb/help/>
Athey, J.E., Seitz, S.S., and Staff, DGGS, 2017, Geologic Photos of Alaska: Digital Data Series DDS 14, Alaska Division of Geological & Geophysical Surveys, Fairbanks, Alaska, United States.
This is a point data set.
The map projection used is GS_1984_Web_Mercator_Auxiliary_Sphere.
Planar coordinates are encoded using coordinate pair
Abscissae (x-coordinates) are specified to the nearest 0.00000001
Ordinates (y-coordinates) are specified to the nearest 0.00000001
Planar coordinates are specified in meters
The horizontal datum used is D_WGS_1984.
The ellipsoid used is WGS_1984.
The semi-major axis of the ellipsoid used is 6378137.000000.
The flattening of the ellipsoid used is 1/298.257223563.
DGGS is appreciative of support from the U.S. Geological Survey's National Geological and Geophysical Data Preservation Program (NGGDPP) for this project. As a NGGDPP project deliverable, the application is available for additional development via a public source code repository. Contact email@example.com for more information
DGGS collects thousands of photographs as part of its field work each year. These photographs primarily document field sites and geomorphology statewide, usually in remote locations that are often impossible or prohibitively expensive to revisit. The database and application provide a vehicle to ensure the future safety and accessibility of the DGGS field photo collection.
Metadata for photographs are of variable quality. The application automatically grabs any available Exif location or date information from digital files and populates the database. Exif header information has been embedded in digital photographs since about 2010 by specific photographic equipment. As of 2017, automatically populated information is more available but not ubiquitous. Information for other attributes and photographs taken prior to 2010 is manually entered, which allows human error. Information for photos taken within a year of data entry will likely be more complete, since the person entering the data will remember more about the observation site. We ask users to please let us know if they have additional information about a photograph site or subject (firstname.lastname@example.org).
Locations were determined based on 1) GPS coordinates embedded in the Exif data of the image file; 2) coordinate values listed in field notes, digitized from a map, or loaded from a digital spreadsheet; or 3) coordinates selected as a point or polygon on the application's internal map based on ancillary information. Consequently, location certainty varies considerably throughout the dataset. Users requiring highly accurate locations for their area of interest should consult the originating data source to determine if the location certainty is within acceptable parameters. Locations may need to be converted WGS84; photos collected in NAD27 datum will have a locational error of about 200 meters. Location accuracy is recorded as good, fair, or poor. Good location accuracy is defined as a known outcrop location or constrained to within several kilometers. Fair accuracy is defined as location known at 1:63,360 scale or larger (+/-10 km). Poor accuracy is defined as location known at smaller than 1:63,360 scale (+/-60 km).
Development of this database is ongoing. Both legacy and new photographs will be added over time.
Referential integrity among the tables is enforced by the database system.
Are there legal restrictions on access or use of the data?
- This report, map, and/or dataset is available directly from the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys (see contact information below).
- Any hard copies or published datasets utilizing these datasets shall clearly indicate their source. If the user has modified the data in any way, the user is obligated to describe the types of modifications the user has made. The user specifically agrees not to misrepresent these datasets, nor to imply that changes made by the user were approved by the State of Alaska, Department of Natural Resources, Division of Geological & Geophysical Surveys. The State of Alaska makes no express or implied warranties (including warranties for merchantability and fitness) with respect to the character, functions, or capabilities of the electronic data or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products or any failure thereof or otherwise. In no event will the State of Alaska's liability to the Requestor or anyone else exceed the fee paid for the electronic service or product.
The State of Alaska makes no expressed or implied warranties (including warranties for merchantability and fitness) with respect to the character, functions, or capabilities of the electronic data or products or their appropriateness for any user's purposes. In no event will the State of Alaska be liable for any incidental, indirect, special, consequential, or other damages suffered by the user or any other person or entity whether from the use of the electronic services or products or any failure thereof or otherwise. In no event will the State of Alaska's liability to the Requestor or anyone else exceed the fee paid for the electronic service or product.
DGGS publications are available as free online downloads or you may purchase paper hard-copies or digital files on CD/DVD or other digital storage media by mail, phone, fax, or email from the DGGS Fairbanks office. To purchase this or other printed reports and maps, contact DGGS by phone (907-451-5020), e-mail (email@example.com), or fax (907-451-5050). Payment accepted: Cash, check, money order, VISA, or MasterCard. Turnaround time is 1-2 weeks unless special arrangements are made and an express fee is paid. Shipping charge will be the actual cost of postage and will be added to the total amount due. Contact us for the exact shipping amount.
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