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| Titel |
Post-LIA glacier changes along a latitudinal transect in the Central Italian Alps |
| VerfasserIn |
R. Scotti, F. Brardinoni, G. B. Crosta |
| 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. 6 ; Nr. 8, no. 6 (2014-12-02), S.2235-2252 |
| Datensatznummer |
250116386
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| Publikation (Nr.) |
 copernicus.org/tc-8-2235-2014.pdf |
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| Zusammenfassung |
| The variability of
glacier response to atmospheric temperature rise in different topo-climatic
settings is still a matter of debate. To address this question in the Central
Italian Alps, we compile a post-LIA (Little Ice Age) multitemporal glacier
inventory (1860–1954–1990–2003–2007) along a latitudinal transect that
originates north of the continental divide in the Livigno Mountains and
extends south through the Disgrazia and Orobie ranges, encompassing
continental-to-maritime climatic settings. In these sub-regions, we examine
the area change of 111 glaciers. Overall, the total glacierized area has
declined from 34.1 to 10.1 km2, with a substantial increase in the number
of small glaciers due to fragmentation. The average annual decrease (AAD) in
glacier area has risen by about 1 order of magnitude from 1860–1990
(Livigno: 0.45; Orobie: 0.42; and Disgrazia: 0.39 % a−1) to
1990–2007 (Livigno: 3.08; Orobie: 2.44; and Disgrazia: 2.27 % a−1).
This ranking changes when considering glaciers smaller than 0.5 km2 only
(i.e., we remove the confounding caused by large glaciers in Disgrazia), so
that post-1990 AAD follows the latitudinal gradient and Orobie glaciers stand
out (Livigno: 4.07; Disgrazia: 3.57; and Orobie: 2.47 % a−1). More
recent (2007–2013) field-based mass balances in three selected small
glaciers confirm post-1990 trends showing the consistently highest retreat in
continental Livigno and minimal area loss in maritime Orobie, with Disgrazia
displaying transitional behavior. We argue that the recent resilience of
glaciers in Orobie is a consequence of their decoupling from synoptic
atmospheric temperature trends, a decoupling that arises from the combination
of local topographic configuration (i.e., deep, north-facing cirques) and
high winter precipitation, which ensures high snow-avalanche supply, as well
as high summer shading and sheltering. Our hypothesis is further supported by
the lack of correlations between glacier change and glacier attributes in
Orobie, as well as by the higher variability in ELA,sub>0 positioning, post-LIA
glacier change, and interannual mass balances, as we move southward along the
transect. |
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