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Abstract
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| Glaciers on islands around the Antarctic Peninsula have shown retreat and surface lowering during the recent decades, concurrent with increasing air temperatures. The Antarctic Peninsula has shown considerable warming with maximum surface air temperature increases of up to 2.5 K in 50 years at Faraday/Vernadsky station. The glaciers on Livingston Island are subject to a maritime climate, and such gaciers are generally considered more sensitive to climate change due to high accumulation rates and temperatures close to the melting point. Hurd and Johnsons glaciers on Livingston Island have shown a reduced mass loss during the period 2001-2011, with average geodetic mass balances of -0.15 and -0.09 m w.e./yr, in contrast with their long term averages (1956-2000) of -0.27 and -0.16 m w.e./yr, respectively. In this study we estimate the ice discharge into the ocean for most of the ice cap, based on a flux gate approach. Ice flux is calculated through pre-defined flux gates close to the ocean terminating ice cap perimeter, yielding a measure of total frontal ablation (sum of calving and marine melting) neglecting any mass changes due to terminus retreat. The flux gates are selected based on availability of surface velocity data close to the calving front. L-band synthetic aperture radar imagery covering the time span between October 2007 and March 2011 are processed using an intensity tracking algorithm to obtain surface velocity measurements. Pixel offsets from 33 pairs of radar images are analyzed and inverted to estimate a weighted average surface velocity field. Ice thickness are derived from simple principles of ice flow mechanics using the computed surface velocity fields and in-situ thickness data | |
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International
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Si |
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Congress
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Earth Observation and Cryosphere Science: Advancing Knowledge of Cryosphere-Atmosphere-Oceans Interaction from Space |
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960 |
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Place
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Frascati, Roma |
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Reviewers
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Si |
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ISBN/ISSN
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Start Date
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13/11/2012 |
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End Date
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16/11/2012 |
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From page
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1 |
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To page
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1 |
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Proc. of Earth Observation and Cryosphere Science |