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Automated delineation of debris-covered glaciers based on ASTER data


Bolch, Tobias; Buchroithner, Manfred F; Kunert, André; Kamp, Ulrich (2007). Automated delineation of debris-covered glaciers based on ASTER data. In: Gomarasca, M A. GeoInformation in Europe. Rotterdam (NL): Millpress, 403-410.

Abstract

Large areas of the glacier tongues at Mt. Everest are heavily covered by supraglacial debris. This hampers the automated mapping of the actual ice snout by means of spaceborne imagery due to the similar spectral signal of the surrounding debris. The most significant features which differentiate the glaciers are the typical surface characteristics like a rough surface or “cryokarst” and a number of ablation ponds. At a first glance the outline of these debris-covered glaciers seems to be stable. Looking in detail at these glaciers using multitemporal space imagery it is obvious that recent glacier shrinkage results in an increasing debris coverage and an increasing number and, hence, area of supra-glacial lakes. In addition, the surface, especially at the very distal part of the glacier, looks smoother and shows no significant indications for movement. Hence, presently ASTER stereo-images represent an ideal tool to develop an automated way of outlining the ice extents of the active and inactive glacier. Combining ASTER’s thermal information with various shape parameters derived from stereo models, both the actual glacier beds and the marginal moraines could be outlined. Mainly due to the resolution of the ASTER DEM (30 m) this concept is only promising for large glaciers such as the Khumbu Glacier. In future, when high resolution DEMs will be available, the accuracy will be sufficient for a fully automated glacier monitoring, including smaller glaciers.

Abstract

Large areas of the glacier tongues at Mt. Everest are heavily covered by supraglacial debris. This hampers the automated mapping of the actual ice snout by means of spaceborne imagery due to the similar spectral signal of the surrounding debris. The most significant features which differentiate the glaciers are the typical surface characteristics like a rough surface or “cryokarst” and a number of ablation ponds. At a first glance the outline of these debris-covered glaciers seems to be stable. Looking in detail at these glaciers using multitemporal space imagery it is obvious that recent glacier shrinkage results in an increasing debris coverage and an increasing number and, hence, area of supra-glacial lakes. In addition, the surface, especially at the very distal part of the glacier, looks smoother and shows no significant indications for movement. Hence, presently ASTER stereo-images represent an ideal tool to develop an automated way of outlining the ice extents of the active and inactive glacier. Combining ASTER’s thermal information with various shape parameters derived from stereo models, both the actual glacier beds and the marginal moraines could be outlined. Mainly due to the resolution of the ASTER DEM (30 m) this concept is only promising for large glaciers such as the Khumbu Glacier. In future, when high resolution DEMs will be available, the accuracy will be sufficient for a fully automated glacier monitoring, including smaller glaciers.

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Additional indexing

Item Type:Book Section, not refereed, original work
Communities & Collections:07 Faculty of Science > Institute of Geography
Dewey Decimal Classification:910 Geography & travel
Language:English
Date:2007
Deposited On:16 May 2017 15:26
Last Modified:04 Jun 2017 18:56
Publisher:Millpress
ISBN:978-90-5966-061-8
Additional Information:Proceedings of the 27th Symposium of the European Association of Remote Sensing Laboratories (EARSeL), Bolzano, Italy, 4 -7 June 2007
Related URLs:http://www.iospress.nl/book/geoinformation-in-europe/

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