Elevation changes (1949–1995) of Black Rapids Glacier, Alaska, derived from a multi-baseline InSAR DEM and historical maps
We have constructed a new digital elevation model (DEM) of the 1995 surface of Black Rapids Glacier, a surge-type glacier in the central Alaska Range, using ERS-1/-2 repeat-pass interferometry. We isolated the topographic phase from three interferograms with contrasting perpendicular baselines. Nume...
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ftuniwashingtaco:oai:digitalcommons.tacoma.uw.edu:ias_pub-1330 2023-09-05T13:11:20+02:00 Elevation changes (1949–1995) of Black Rapids Glacier, Alaska, derived from a multi-baseline InSAR DEM and historical maps Shugar, Dan H. Rabus, Bernhard T. Clague, John J. 2010-10-01T07:00:00Z https://digitalcommons.tacoma.uw.edu/ias_pub/331 https://doi.org/10.3189/002214310793146278 https://doi.org/10.3189/00221431079314627https://doi.org/10.3189/00221431079314627 unknown UW Tacoma Digital Commons https://digitalcommons.tacoma.uw.edu/ias_pub/331 doi:10.3189/002214310793146278 https://doi.org/10.3189/00221431079314627https://doi.org/10.3189/00221431079314627 SIAS Faculty Publications text 2010 ftuniwashingtaco https://doi.org/10.3189/00221431079314627810.3189/00221431079314627https://doi.org/10.3189/00221431079314627 2023-08-21T14:13:55Z We have constructed a new digital elevation model (DEM) of the 1995 surface of Black Rapids Glacier, a surge-type glacier in the central Alaska Range, using ERS-1/-2 repeat-pass interferometry. We isolated the topographic phase from three interferograms with contrasting perpendicular baselines. Numerous phase-unwrapping errors caused by areas of poor coherence were corrected in all three interferograms, using a novel, iterative, semi-automated approach that capitalizes on the multi-baseline nature of the dataset. Comparison of our DEM with a 1949 US Geological Survey DEM and with 1973–95 ground survey data shows the gradual return of Black Rapids Glacier to a presurge hypsometry following a surge in 1936/37. Maximum elevation changes along the glacier center line in the ablation and accumulation areas are, respectively, −249 and +63 m (−5.4 and +1.4 m a−1). Maximum elevation changes of survey points at nearby locations are −4.9 m a−1 (1975–84) and +0.5 m a−1 (1975–85). Center-line thickening of +62 m between 1949 and 1995 (+1.4 m a−1), just above the Loket tributary in the upper part of the ablation zone, indicates dynamic thickening following the 1936/37 surge. Text alaska range glacier Alaska University of Washington: UW Tacoma Digital Commons |
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University of Washington: UW Tacoma Digital Commons |
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ftuniwashingtaco |
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unknown |
description |
We have constructed a new digital elevation model (DEM) of the 1995 surface of Black Rapids Glacier, a surge-type glacier in the central Alaska Range, using ERS-1/-2 repeat-pass interferometry. We isolated the topographic phase from three interferograms with contrasting perpendicular baselines. Numerous phase-unwrapping errors caused by areas of poor coherence were corrected in all three interferograms, using a novel, iterative, semi-automated approach that capitalizes on the multi-baseline nature of the dataset. Comparison of our DEM with a 1949 US Geological Survey DEM and with 1973–95 ground survey data shows the gradual return of Black Rapids Glacier to a presurge hypsometry following a surge in 1936/37. Maximum elevation changes along the glacier center line in the ablation and accumulation areas are, respectively, −249 and +63 m (−5.4 and +1.4 m a−1). Maximum elevation changes of survey points at nearby locations are −4.9 m a−1 (1975–84) and +0.5 m a−1 (1975–85). Center-line thickening of +62 m between 1949 and 1995 (+1.4 m a−1), just above the Loket tributary in the upper part of the ablation zone, indicates dynamic thickening following the 1936/37 surge. |
format |
Text |
author |
Shugar, Dan H. Rabus, Bernhard T. Clague, John J. |
spellingShingle |
Shugar, Dan H. Rabus, Bernhard T. Clague, John J. Elevation changes (1949–1995) of Black Rapids Glacier, Alaska, derived from a multi-baseline InSAR DEM and historical maps |
author_facet |
Shugar, Dan H. Rabus, Bernhard T. Clague, John J. |
author_sort |
Shugar, Dan H. |
title |
Elevation changes (1949–1995) of Black Rapids Glacier, Alaska, derived from a multi-baseline InSAR DEM and historical maps |
title_short |
Elevation changes (1949–1995) of Black Rapids Glacier, Alaska, derived from a multi-baseline InSAR DEM and historical maps |
title_full |
Elevation changes (1949–1995) of Black Rapids Glacier, Alaska, derived from a multi-baseline InSAR DEM and historical maps |
title_fullStr |
Elevation changes (1949–1995) of Black Rapids Glacier, Alaska, derived from a multi-baseline InSAR DEM and historical maps |
title_full_unstemmed |
Elevation changes (1949–1995) of Black Rapids Glacier, Alaska, derived from a multi-baseline InSAR DEM and historical maps |
title_sort |
elevation changes (1949–1995) of black rapids glacier, alaska, derived from a multi-baseline insar dem and historical maps |
publisher |
UW Tacoma Digital Commons |
publishDate |
2010 |
url |
https://digitalcommons.tacoma.uw.edu/ias_pub/331 https://doi.org/10.3189/002214310793146278 https://doi.org/10.3189/00221431079314627https://doi.org/10.3189/00221431079314627 |
genre |
alaska range glacier Alaska |
genre_facet |
alaska range glacier Alaska |
op_source |
SIAS Faculty Publications |
op_relation |
https://digitalcommons.tacoma.uw.edu/ias_pub/331 doi:10.3189/002214310793146278 https://doi.org/10.3189/00221431079314627https://doi.org/10.3189/00221431079314627 |
op_doi |
https://doi.org/10.3189/00221431079314627810.3189/00221431079314627https://doi.org/10.3189/00221431079314627 |
_version_ |
1776204287308726272 |