ESA project AO2.USA163, PI C.S. Lingle.

Dynamic Behavior of the Bering Glacier-Bagley Icefield
System During a Surge, and Other Measurements of
Alaskan Glaciers with ERS SAR Imagery

Craig S. Lingle, Dennis R. Fatland, Vera A. Voronina,
and Kristina Ahlnaes, Geophysical Institute, University of
Alaska Fairbanks, Fairbanks, Alaska 99775-7320, U.S.A.,
clingle@gi.alaska.edu

SAR imagery has yielded a broad spectrum of
measurements of the dynamic behavior of Alaskan
glaciers and icefields.  Differential SAR interferometry
based on 3- and 6-day image pairs acquired during the
ERS-1 3-day orbit cycles have yielded detailed
quantitative measurements of the surface velocity field
and topography of Bagley Icefield and its tributaries
during the massive 1993-95 surge of Bering Glacier, for
which Bagley Icefield is the accumulation area, and of the
velocity increase on Bagley Icefield between 1992, prior
to the surge, and 1994 when the surge was in full progress.
At the eastern end of the Bering-Bagley-Seward-Malaspina
Glacier system, which constitutes the largest glacier and
icefield system in the world outside Antarctica and
Greenland, an analysis method based on cross-correlation
of full-resolution (amplitude) SAR images, separated by
one year, has yielded a detailed surface velocity field for
Malaspina Glacier.  Gridding of the velocities and
computation of principal strain rates shows promise of
permitting an evaluation of the periodic surge hypothesis
for formation of the immense folded moraines that
characterize the surface of this large piedmont glacier.
On Mt. Wrangell, a high but gently-sloping and heavily
ice-covered volcano, use of terrain corrected
SAR imagery has permitted mapping of late-summer
snow lines and clear identification of snow facies.  A
summary of these studies will be presented.
 

Keywords: ESA European Space Agency - Agence spatiale europeenne, observation de la terre, earth observation, satellite remote sensing, teledetection, geophysique, altimetrie, radar, chimique atmospherique, geophysics, altimetry, radar, atmospheric chemistry