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| Titel |
Tracing glacier changes since the 1960s on the south slope of Mt. Everest (central Southern Himalaya) using optical satellite imagery |
| VerfasserIn |
S. Thakuri, F. Salerno, C. Smiraglia, T. Bolch, C. D'Agata, G. Viviano, G. Tartari |
| 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 ; 8, no. 4 ; Nr. 8, no. 4 (2014-07-22), S.1297-1315 |
| Datensatznummer |
250116249
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| Publikation (Nr.) |
 copernicus.org/tc-8-1297-2014.pdf |
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| Zusammenfassung |
| This contribution examines glacier changes on the south side of Mt. Everest
from 1962 to 2011 considering five intermediate periods using optical
satellite imagery. The investigated glaciers cover ~ 400 km2
and present among the largest debris coverage (32%)
and the highest elevations (5720 m) of the world. We found an overall
surface area loss of 13.0 ± 3.1% (median 0.42 ± 0.06 % a−1),
an upward shift of 182 ± 22 m (3.7 ± 0.5 m a−1)
in snow-line altitude (SLA), a terminus retreat of 403 ± 9 m (median
6.1 ± 0.2 m a−1), and an increase of 17.6 ± 3.1%
(median 0.20 ± 0.06% a−1) in debris coverage between 1962 and
2011. The recession process of glaciers has been relentlessly continuous
over the past 50 years. Moreover, we observed that (i) glaciers that have
increased the debris coverage have experienced a reduced termini retreat (r = 0.87,
p < 0.001). Furthermore, more negative mass balances (i.e.,
upward shift of SLA) induce increases of debris coverage (r = 0.79,
p < 0.001); (ii) since early 1990s, we observed a slight but statistically
insignificant acceleration of the surface area loss (0.35 ± 0.13% a−1
in 1962–1992 vs 0.43 ± 0.25% a−1 in 1992–2011),
but an significant upward shift of SLA which increased almost three times
(2.2 ± 0.8 m a−1 in 1962–1992 vs 6.1 ± 1.4 m a−1 in
1992–2011). However, the accelerated shrinkage in recent decades (both in
terms of surface area loss and SLA shift) has only significantly affected
glaciers with the largest sizes (> 10 km2), presenting
accumulation zones at higher elevations (r = 0.61, p < 0.001) and
along the preferable south–north direction of the monsoons. Moreover, the
largest glaciers present median upward shifts of the SLA (220 m) that are
nearly double than that of the smallest (119 m); this finding leads to a hypothesis
that Mt. Everest glaciers are shrinking, not only due to warming
temperatures, but also as a result of weakening Asian monsoons registered
over the last few decades. We conclude that the shrinkage of the glaciers in
south of Mt. Everest is less than that of others in the western and eastern
Himalaya and southern and eastern Tibetan Plateau. Their position in higher
elevations have likely reduced the impact of warming on these glaciers, but
have not been excluded from a relentlessly continuous and slow recession
process over the past 50 years. |
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