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tab_left Change Detection Results tab_right

Using the measuring tool in ArcGIS you can measure the linear retreat in the terminus which, at the location shown in the figure, is of the order of about 400 m between 2000 and 2005.

Linear retreat of the terminus
Using image data alone measured linear glacier retreat at this location is about 400 m. Data processed by Rudi Gens

A comparison of the 2000 and August 2005 terminus positions indicates that a significant amount of the ice loss occurred along the lacustrine glacier terminus, in particular along its eastern half. This is consistent with field-based observations of the calving terminus over the five-year interval between the images.

Warren et al (2001) noted that lacustrine glacier termini typically undergo a period of downwasting and narrowing prior to the onset of rapid terminus retreat. The behavior of Mendenhall Glacier agrees qualitatively with observations of other lake-calving glaciers.

tab_left Change in Lake Extent tab_right

The area that was earlier occupied by the glacier and has now converted to the Mendenhall Lake water can also be calculated by drawing a polygon shapefile using visual interpretation.

Between 1986 and 2005 the surface area that converted from glacial cover to lake water is shown in the figure below in a blue outline. The area is in the order of 0.68 square kilometers.

sea ice classification
Blue polygon showing increase in Mendenhall lake area between 1986 and 2005. Data processed by Rudi Gens

logos Geophysical Institute University of Alaska Fairbanks Alaska Space Grant Program