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The Estimation of the relative intensity of different cold periods occurring during the Late Quaternary is a difficult task, particularly in non-glaciated mountain landscapes and where high- to medium-resolution archives for proxy data are lacking. In this paper, we study a Holocene polycyclic soil sequence in the central Alps (Val Cavargna, Northern Italy) to estimate climatic parameters (specifically Temperature) changes in non-glaciated, high altitude environments. We investigate this key site through palaeopedological and micromorphological analyses in order to understand phases of soil development and detect hidden evidence of cold conditions during its formation. Three phases of pedogenesis can be recognized and attributed in time to different periods during the Holocene. Pedogenetic phases were separated by two truncation and deposition episodes related to the reactivation of slope processes under cold conditions at the onset of the Neoglacial and the Iron Age Cold Epoch, respectively. Micromorphological evidence of frost action in the soil can instead relate to pedogenetic processes acting in the Little Ice Age. The different expression of these three cold periods corresponds to changes in climatic conditions, pointing to the Little Ice Age as a cooler/drier period in comparison to the preceding ones. [ABSTRACT FROM AUTHOR]

Over the last decades, the expansion of supraglacial debris on worldwide mountain glaciers has been reported. Nevertheless, works dealing with the detection and mapping of supraglacial debris and detailed analyses aimed at identifying the temporal and spatial trends affecting glacier debris cover are still limited. In this study, we used different remote sensing sources to detect and map the supraglacial debris cover, to analyze its evolution, and to assess the potential of different remote-sensed image data. We performed our analyses on the glaciers of Ortles-Cevedale Group (Stelvio Park, Italy), one of the most representative glacierized sectors of the European Alps. High-resolution airborne orthophotos (pixel size 0.5 m × 0.5 m) acquired during the summer season in the years 2003, 2007, and 2012 permitted to map in detail, with an error lower than ±5%, the supraglacial debris cover through a maximum likelihood classification. Our findings suggest that over the period 2003–2012, supraglacial debris cover increased from 16.7% to 30.1% of the total glacier area. On Forni Glacier we extended these quantification thanks to the availability of UAV (Unmanned Aerial Vehicle) orthophotos from 2014 and 2015 (pixel size 0.15 m × 0.15 m): this detailed analysis permitted to confirm debris is increasing on the glacier melting surface (+20.4%) and confirms the requirement of high-resolution data in debris mapping on Alpine glaciers. Finally, we also checked the suitability of medium-resolution Landsat ETM+ data and Sentinel 2 data to map debris in a typical Alpine glaciation scenario where small ice bodies (<0.5 km2) are the majority. The results we obtained suggest that medium-resolution data are not suitable for a detailed description and evaluation of supraglacial debris cover in the Alpine scenario, nevertheless Sentinel 2 proved to be appropriate for a preliminary mapping of the main debris features. [ABSTRACT FROM AUTHOR]

Here three glacier surface area records (years 1975, 1999 and 2005) available for Aosta Valley (western Italian Alps) have been synthesized. The 1975 data have been collected by previous authors who compiled the first Aosta Valley regional glacier database. The 1999 and 2005 surface area data were computed by the authors here combining registered colour orthophotos with differential GPS (DGPS) field measurements. The surface changes of 174 glaciers (those shared within the three records of data) were calculated to describe the recent evolution of a representative subset of Italian glaciers. Aosta Valley glaciers lost 44.3 km2 during 1975–2005, i.e. c. 27% of the initial area. Small glaciers contributed strongly to total area loss, and during 2005 147 glaciers (c. 84.5% of the studied ones) were smaller than 1 km2, covering 20.7 km2 (c. 17% of the total area), but accounted for 43% of the total loss in area (losing 19 km2 from 1975 to 2005). The area change rate accelerated recently (1999–2005: mean area loss of c. 2.8 km2/year; 1975–1999: mean area loss of c. 1.1 km2/year). We then analyse records (1975–2005) of temperature, precipitation and snow cover from three high-altitude (1332 m asl to 3488 m asl) stations within Aosta Valley, to investigate modified climate within the area. We find increasing temperature especially during late spring and summer, and substantially unchanged total precipitation, with marked reduction of snowfall, snow cover, number of snowfall events and duration of continuous snow cover, especially during spring and summer, likely driving shrinking of glacier coverage. [ABSTRACT FROM AUTHOR]