A new satellite-derived glacier inventory for western Alaska

• Published in: Annals of Glaciology
• Main Authors: Bris, R. Le, Paul, F., Frey, H., Bolch, T.
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2011
• Subjects: New Glacier; Annals of Glaciology; glacier; glaciers; Alaska
• Online Access: https://research-portal.st-andrews.ac.uk/en/publications/fa2dbb79-c1b3-43a7-905c-1f94ee4a7fc4; https://doi.org/10.3189/172756411799096303; http://www.scopus.com/inward/record.url?scp=84856504998&partnerID=8YFLogxK

Glacier inventories provide the baseline data to perform climate-change impact assessment on a regional scale in a consistent and spatially representative manner. In particular, a more accurate calculation of the current and future contribution to global sea-level rise from heavily glacierized regions such as Alaska is much needed. We present a new glacier inventory for a large part of western Alaska (including Kenai Peninsula and the Tordrillo, Chigmit and Chugach mountains), derived from nine Landsat Thematic Mapper scenes acquired between 2005 and 2009 using well-established automated glacier-mapping techniques (band ratio). Because many glaciers are covered by optically thick debris or volcanic ash and partly calve intowater, outlineswere manually edited in these wrongly classified regions during post-processing. In total we mapped ~8830 glaciers (>0.02 km 2 ) with a total area of ~16 250 km 2 . Large parts of the area (47%) are covered by a few (31) large (>100 km 2 ) glaciers, while glaciers less than 1km 2 constitute only 7.5% of the total area but 86% of the total number.We found a strong dependence of mean glacier elevation on distance from the ocean and only aweak one on aspect. Glacier area changes were calculated for a subset of 347 selected glaciers by comparison with the Digital Line Graph outlines from the US Geological Survey. The overall shrinkage was ~23% between 1948-57 and 2005-09.