GEODETIC ASSESSMENT OF VOLUME AND SURFACE CHANGE OF THE LEMON CREEK GLACIER BETWEEN 1948 AND 2000

Mass balance measurements have annually been compiled on the Lemon Creek Glacier since 1953, by the Juneau Icefield Research Program. Several studies used geodetic methods to assess the volume change of Lemon Creek Glacier, however these occur with 40 year time steps. In order to be of significant constraint to long-term mass balance studies, approximately decadal geodetic time steps are needed. This paper describes a compilation of aerial photography, topographic maps, radar topography to create a set of digital elevation models (DEM’s) with decadal time steps. The 1957 and 1989 topographic maps of the Lemon Creek Glacier will be geo-referenced to a recent Landsat image and contour lines digitized to create DEM’s which complete the existing data. Using DEM differencing the full data set is then examined to yield data regarding volume and surface change on the Lemon Creek Glacier in decadal time steps. Statistics from the volume change evaluation are manipulated to reflect glacier wide mass balance, which can be compared with the existing mass balance ground measurements.