Top of this page

Mass Balance, Meteorological, Ice Motion, Surface Altitude, Runoff, and Ice Thickness Data at Gulkana Glacier, Alaska, 1995

by Rod S. March

U.S. GEOLOGICAL SURVEY
Water-Resources Investigations Report 00-4074

ABSTRACT

The 1995 measured winter snow, maximum winter snow, net, and annual balances in the Gulkana Glacier basin were evaluated on the basis of meteorological, hydrological, and glaciological data obtained in the basin. Averaged over the glacier, the measured winter snow balance was 0.94 meter on April 19, 1995, 0.6 standard deviation below the long-term average; the maximum winter snow balance, 0.94 meter, was reached on April 25, 1995; the net balance (from September 18, 1994 to August 29, 1995) was -0.70 meter, 0.76 standard deviation below the long-term average. The annual balance (October 1, 1994, to September 30, 1995) was -0.86 meter. Ice-surface motion and altitude changes measured at three index sites document seasonal ice speed and glacier-thickness changes. Annual stream runoff was 2.05 meters averaged over the basin, approximately equal to the long-term average. 

The 1976 ice-thickness data are reported from a single site near the highest measurement site (180 meters thick) and from two glacier cross profiles near the mid-glacier (270 meters thick on centerline) and low glacier (150 meters thick on centerline) measurement sites. 

A new area-altitude distribution determined from 1993 photogrammetry is reported. Area-averaged balances are reported from both the 1967 and 1993 area-altitude distribution so the reader may directly see the effect of the update. Briefly, loss of ablation area between 1967 and 1993 results in a larger weighting being applied to data from the upper glacier site and hence, increases calculated area-averaged balances. The balance increase is of the order of 15 percent for net balance.

March, R. S., 2000, Mass balance, meteorological, ice motion, surface altitude, runoff, and ice thickness data at Gulkana Glacier, Alaska, 1995 balance year: U.S. Geological Survey Water-Resources Investigations Report 00-4074, 33 p.

  [Full Report, Acrobat PDF (2.8 MB)]

Adobe Acrobat's .pdf (portable document file) format can be viewed using the free Adobe Acrobat Reader available for DOS, Windows, Macintosh, and UNIX. This link will allow you to get the free download and installation instructions from Adobe.