Task 5 Denali Digitizing Project of Glacial Extents

Glaciers cover a large portion of Alaska National Parks, and Denali in particular. As glaciers advance, plant communities are subsumed.  As they retreat, plant communities colonize the newly exposed areas, and the plant cover changes as one plant community succeeds another.  An on-going effort has been made to monitor the annual and long term retreats and advances of the park's glaciers.  Present day activities involve surveying of glacial termini and the equilibrium zone of selected glaciers. Little information exists regarding historic positions of glaciers within the park.  One useful source of historic baseline extents is contained within the USGS topographic quad maps.  Theses maps are at a scale of 1:63,360 and mainly date from the 1950's.  The park already possessed glacial extents in digital format from this source for the McKinley and a portion of the Healy quadrangles.  The park did not have the remainder of the Healy quadrangle, nor any digital coverage of the Talkeetna quadrangle. This project completed the digitization of these extents for the 18 remaining map sheets in the Healy and Talkeetna quadrangles.    The resulting polygon coverages were then edgematched, attributed and appended to the existing McKinley and Healy coverages to create a single coverage of the glacial extents in Denali.   This final double precision coverage had the following geospatial parameters:

Projection:                    Albers Equal Area
Units:                            Meters
Spheroid:                      Clarke1866
Datum:                          NAD27
1st standard parallel:      55 00 00
2nd standard parallel     65 00 00
Central meridian            -154 00 00
Latitude of projection's origin    50 00 00
False easting (meters)                0.0000
False northing (meters)              0.0000