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| Titel |
Geochemical characterization of supraglacial debris via in situ and optical remote sensing methods: a case study in Khumbu Himalaya, Nepal |
| VerfasserIn |
K. A. Casey, A. Kääb, D. I. Benn |
| Medientyp |
Artikel
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| Sprache |
Englisch
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| ISSN |
1994-0416
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| Digitales Dokument |
URL |
| Erschienen |
In: The Cryosphere ; 6, no. 1 ; Nr. 6, no. 1 (2012-01-19), S.85-100 |
| Datensatznummer |
250003376
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| Publikation (Nr.) |
 copernicus.org/tc-6-85-2012.pdf |
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| Zusammenfassung |
| Surface glacier debris samples and field spectra were collected from the
ablation zones of Nepal Himalaya Ngozumpa and Khumbu glaciers in November
and December 2009. Geochemical and mineral compositions of supraglacial debris were
determined by X-ray diffraction and X-ray fluorescence spectroscopy.
This composition data was used as ground truth in evaluating field spectra and satellite
supraglacial debris composition and mapping methods. Satellite remote sensing methods
for characterizing glacial surface debris include visible to thermal infrared hyper-
and multispectral reflectance and emission signature identification, semi-quantitative mineral abundance indicies and
spectral image composites. Satellite derived supraglacial debris mineral maps displayed
the predominance of layered silicates, hydroxyl-bearing and calcite
minerals on Khumbu Himalayan glaciers. Supraglacial mineral maps compared
with satellite thermal data revealed correlations
between glacier surface composition and glacier surface temperature. Glacier velocity displacement
fields and shortwave, thermal infrared false color composites indicated the magnitude of
mass flux at glacier confluences. The
supraglacial debris mapping methods presented in this study can be used on a
broader scale to improve, supplement and potentially reduce errors associated
with glacier debris radiative property, composition, areal extent and mass
flux quantifications. |
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