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Reconstruction of rock avalanche history in Val Viola, (Upper Valtellina, Italian Central Alps) through 10Be exposure ages, Schmidt Hammer R values, and surface roughness.

Authors :
Longhi, Alessandro
Morgan, Daniel
Guglielmin, Mauro
Source :
Landslides. May2024, Vol. 21 Issue 5, p949-962. 14p.
Publication Year :
2024

Abstract

We investigated the paraglacial evolution and permafrost degradation of Val Viola (Upper Valtellina, Central Italian Alps) through a geomorphologic survey, cosmogenic dating, Schmidt's Hammer, and surface roughness measurements. Our results reveal that the previously mapped Val Viola rock avalanche is probably derived by three different events that occurred 7.7 ± 0.2 ka (Orthogneiss_ 1), 7.0 ± 0.2 ka (Paragneiss), and 5.0 ± 0.3 ka (Orthogneiss_2). Because the main valley bottom has been ice free since at least 12.6 ka, it is unlikely that the triggering factor of these events was the debutressing stress caused by the melting of local valley glaciers. Therefore, permafrost that formed in this area down to 2525 m a.s.l. at 9.3–8 ka and degraded successively between 7.8 and 6.5 ka was likely the main triggering factor of the first two rock avalanche events, as well as for the third event that happened during the warm and wet period of the Holocene Thermal Maximum around 5 ka. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
1612510X
Volume :
21
Issue :
5
Database :
Academic Search Index
Journal :
Landslides
Publication Type :
Academic Journal
Accession number :
176726559
Full Text :
https://doi.org/10.1007/s10346-024-02210-2