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An application of the Complete Automatic Seismic Processor (CASP) for seismic monitoring is presented. Its integrated and iterative fully automatic procedure is able to achieve complete data analysis and significantly rapid elaborations. Its performance in real-time seismic monitoring and alerting is tested in the Trentino region (NE Italy) for the period 1st March 2018 – 31st August 2019. CASP precisely and accurately located 386 seismic events, with local magnitudes in the -0.8–3.4 range, and produced a seismic catalogue with a magnitude of completeness around 1.1. Automatic earthquake solutions, with average horizontal and vertical errors of 1.1 and 1.5 km, are very similar to those included in a manually revised reference catalogue. In addition, 146 detected events are located in the area of the local porphyry quarries. CASP alerts are delivered as Short Message Service (SMS), Telegram and e-mail messages within an average time of just over two minutes from the earthquake origin time. These alerts contain earthquake source parameters, ground shaking levels and instrumental intensities. CASP reliability, promptness and robustness permit to civil protection and decision makers to perform a monitoring primarily dedicated to emergency management, in order to evaluate both seismic sources and their effects (peak ground acceleration) at local targets, such as more inhabited territories and critical infrastructures (dams and hydropower plants).

The study of plant phenology has frequently been used to link phenological events to various factors, such as temperature or photoperiod. In the high-alpine environment, proper timing of the phenological cycle has always been crucial to overcome harsh conditions and potential extreme events (i.e. spring frosts) but little is known about the response dynamics of the vegetation, which could shape the alpine landscape in a future of changing climate. Alpine tundra vegetation is composed by an array of species belonging to different phytosociological optima and with various survival strategies, and snowbed communities are a relevant expression of such an extreme-climate adapted flora. We set eight permanent plots with each one in a snowbed located on the Cimalegna plateau in Northwestern Italy and then we selected 10 most recurring species among our plots, all typical of the alpine tundra environment and classified in 3 different pools: snowbed specialists, grassland species and rocky debris species. For 3 years we registered the phenophases of each species during the whole growing season using an adaptation of the BBCH scale. We later focused on the three most biologically relevant phenophases, i.e., flower buds visible, full flowering, and beginning of seed dispersion. Three important season-related variables were chosen to investigate their relationship with the phenological cycle of the studied species: (i) the Day Of Year (DOY), the progressive number of days starting from the 1st of January, used as a proxy of photoperiod, (ii) Days From Snow Melt (DFSM), selected to include the relevance of the snow dynamics, and (iii) Growing Degree Days (GDD), computed as a thermal sum. Our analysis highlighted that phenological development correlated better with DFSM and GDD than with DOY. Indeed, models showed that DOY was always a worse predictor since it failed to overcome interannual variations, while DFSM and marginally GDD were better suited to predict the phenological development of most of the species, despite differences in temperature and snowmelt date among the three years. Even if the response pattern to the three variables was mainly consistent for all the species, the timing of their phenological response was different. Indeed, species such as Salix herbacea and Ranunculus glacialis were always earlier in the achievement of the phenophases, while Agrostis rupestris and Euphrasia minima developed later and the remaining species showed an intermediate behavior. However, we did not detect significant differences among the three functional pools of species.

The aim of the present work is to investigate the role exerted by selected environmental factors in the activation of rainfall-triggered shallow landslides and to identify site-specific rainfall thresholds. The study concerns the Italian Alps. The region is exposed to widespread slope instability phenomena due to its geological, morphological and climatic features. Furthermore, the high level of anthropization that characterizes wide portions of the territory increases the associated risk. Hence, the analysis of potential predisposing factors influencing landslides triggering is worthwhile to improve the current prediction skills and to enhance the preparedness and the response to these natural hazards. During the last years, the Italian National Research Council's Research Institute for Hydro-geological Protection (CNR-IRPI) has contributed to the analysis of triggering conditions for rainfall-induced landslides in the framework of a national project. The project, funded by the National Department for Civil Protection (DPC), focuses on the identification of the empirical rainfall thresholds for the activation of shallow landslides in Italy. The first outcomes of the project reveal a certain variability of the pluviometric conditions responsible for the mass movements activation, when different environmental settings are compared. This variability is probably related to the action of local environmental factors, such as lithology, climatic regime or soil characteristics. Based on this hypothesis, the present study aims to identify separated domains within the Italian Alps, where different triggering conditions exist and different countermeasures are needed for risk prevention. For this purpose, we collected information concerning 511 landslides activated in the period 2000–2012 and reconstructed 453 rainfall events supposed to be responsible for the activations. Then, we selected a set of thematic maps to represent the hypothesised landslide conditioning factors and to identify the supposed homogeneous domains within the study area. We employed an existing statistical method for the definition of the cumulated event rainfall vs. rainfall duration (ED) thresholds, for both the entire catalogue of rainfall events and for the events falling in the separated domains. The obtained results contribute to a better understanding of the role exerted by geological, pedological and climatic factors in landslides activation and help identifying separated domains where different risk managing strategies should be adopted. The proposed methodology can be a valid support for risk reduction strategies planning at regional scale.

Remote sensing investigations permit to map and describe at a regional scale and with a multi-temporal approach mountain glaciers. In this work, we present some results from the New Italian Glacier Inventory which we developed by analyzing high-resolution color orthophotos acquired in the timeframe 2005-2011. In particular, in this paper we focused on each Italian Alpine Region, describing in detail glacier extent and features of each mountain group. Although Italian glaciologists were the first to produce glacier inventories (developing a glacier database as early as the beginning of the 20th century), during the last three decades only regional and local glacier lists have been developed. Therefore, a comprehensive study describing the actual whole Italian glaciation has been lacking. The New Italian Glacier Inventory describes 903 glaciers covering altogether an area of 368.10 km(2) +/- 2%. We found that about 84% of the total number of ice bodies is composed of glaciers smaller than 0.5 km(2) covering only 21% of the total area, indicating that the Italian glacier resource is spread into several small ice bodies with only few larger glaciers. A comparison between the total glacier area of the new inventory and the glacier coverage value from the CGI Inventory (1959-1962) suggests a reduction of the glacier extent of about 30%.

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.

Global warming and the associated glacier retreat recently revealed the entrance to an ice–rock tunnel, at an altitude of ~3600 m a.s.l., in the uppermost portion of the Forni Glacier in the Central Italian Alps. The tunnel served as an entrance to an Austro-Hungarian cableway station excavated in the rocks during the Great War just behind the frontline. A comprehensive geophysical survey, based on seismic and ground-penetrating radar profiling, was then undertaken to map other possible World War I (WWI) remains still embedded in the ice. The ice–rock interface was reconstructed over the entire saddle and in the uppermost portion of the glacier. A prominent linear reflector was surprisingly similar to the common response of buried pipes. The reflector orientation, almost longitudinal to the slope, does not seem to be compatible with a glacial conduit or with other natural features. Numerical simulations of a series of possible targets constrained interpretation to a partly water-filled rounded shape cavity. The presence of a preserved WWI tunnel connecting Mount Vioz and Punta Linke could be considered a realistic hypothesis. The Forni glacier could be still considered polythermal and comprised of cold ice without basal sliding in its top portion.

Carabid beetles and chironomid midges are two dominant cold-adapted taxa, respectively on glacier forefiel terrains and in glacial-stream rivers. Although their sensitivity to high altitude climate warming is well known, no studies compare the species assemblages exhibited in glacial systems. Our study compares diversity and distributional patterns of carabids and chironomids in the foreland of the receding Amola glacier in central-eastern Italian Alps. Carabids were sampled by pitfall traps; chironomids by kick sampling in sites located at the same distance from the glacier as the terrestrial ones. The distance from the glacier front was considered as a proxy for time since deglaciation since these variables are positively correlated. We tested if the distance from the glacier front affects: i) the species richness; ii) taxonomic diversity; and iii) species turnover. Carabid species richness and taxonomic diversity increased positively from recently deglaciated sites (those c. 160 m from the glacier front) to sites deglaciated more than 160yrs ago (those located >1300 m from glacier front). Species distributions along the glacier foreland were characterized by mutually exclusive species. Conversely, no pattern in chironomid species richness and turnover was observed. Interestingly, taxonomic diversity increased significantly: closely related species were found near the glacier front, while the most taxonomically diverse species assemblages were found distant from the glacier front. Increasing glacial retreat differently affect epigeic and aquatic insect taxa: carabids respond faster to glacier retreat than do chironomids, at least in species richness and species turnover patterns.

A pronounced climate reorganization characterized the Lateglacial–Holocene transition in the Northern Hemisphere. Glaciers in the Alps reacted to the last climate deterioration at the end of the Late Pleistocene leaving landscape features suitable for reconstructing Lateglacial and early Holocene history. In this context, the Upper Peio Valley in the Ortles-Cevedale Group (Rhaetian Alps, Italy) has well-preserved moraines of La Mare Glacier and Careser Glacier, which we used to reconstruct the glaciers' behaviour and to investigate the Lateglacial–Holocene transition. Detailed glacier reconstructions combined with 11 new 10Be exposure ages allow dating of the response of these glaciers to the Younger Dryas (YD) cold event. La Mare and Careser glaciers reacted to the YD with a double response, building two clear moraine sets. Data from La Mare Glacier indicate the first advance occurred prior to 12.3±0.7 ka (before 10.0±0.7 ka at Careser Glacier). Both glaciers then re-advanced before 11.2±0.8 ka as dated at La Mare Glacier. This phase can be interpreted as the Egesen stadial glaciers' expression of the end of the YD. Morphometric parameters of the reconstructed phases allowed the estimation of areal and volumetric variations of the studied glaciers as well as equilibrium line altitude (ELA). ΔELA with respect to the Little Ice Age (LIA) maximum position are −225 m for La Mare Glacier and −180 m for the Careser Glacier. Although the behaviour of the two glaciers showed coherence during the Egesen stadial and the LIA, they have behaved individually since then. La Mare has lost 60% of its area, while Careser has lost 85% since the latest Pleistocene. We attribute this to the greater proportion of ice at high elevation of the La Mare Glacier, underlining the importance of bed hypsometry in glacier response.

The Little Ice Age (LIA) is a well-recognized climatic event during which the glaciers in the Alps advanced and reached their maximum Holocene extent. During their retreat following the LIA, the glaciers left large areas of loose or poorly consolidated glacial deposits in their forelands, which are subject to paraglacial reworking and may represent potential hazards for human infrastructures. In this study, we present a regional scale mapping of the LIA and post-LIA glacial deposits and a reconstruction of the maximum LIA extents of glaciers in the same area. This work is motivated by a local law requiring the classification of areas subject to natural hazards in Trentino (Italian Alps). Results highlight that glaciers shrunk by 63% from the LIA maximum, leaving 30 km 2 of unconsolidated deposits, which are subject to geomorphic paraglacial processes. Potentially hazardous consequences can occur, in particular, during high-magnitude instantaneous events, causing debris and mud flows, mass wasting from debris-covered ice, and floods from small moraine-dammed lakes.

Climate change is seriously affecting the cryosphere, in terms, for example of permafrost thaw, alteration of rain/snow ratio, glacier shrinkage. There is concern about the increasing number of rockfalls at high elevation in the last decades. Nevertheless, the impact of climate variables on slope instability at high elevation has not been fully explored yet. In this paper, we investigate 41 rockfalls occurred at high elevation in the Italian Alps between 1997 and 2013 in the absence of an evident trigger. We apply and improve an existing data-based, statistical approach to detect the anomalies of climate parameters (temperature and precipitation) associated to rockfall occurrences. The identified climate anomalies have been related to the spatio-temporal distribution of the events. Rockfalls occurred in association with temperature anomalies in 83 % of our case studies. Temperature represents a key factor contributing to slope failure occurrence in different ways. As expected, warmer temperatures accelerate snowmelt and permafrost thaw; however, surprisingly, negative anomalies are also often associated to slope failures. Interestingly, different regional patterns emerge from the data: higher-than-average temperatures are often associated to rockfalls in the Western Alps, while in the Eastern Alps slope failures are mainly associated to colder-than-average temperatures. The results of this study represent a first step towards the identification of the possible role of climate change in the triggering of slope failures in a mountain environment.

A revised seismic catalogue (1994–2007) for the central–eastern Alps (N Italy) is presented. 396 earthquake relocations, for local magnitudes in the 1.2–5.3 range, are performed using a 3D crustal velocity structure and probabilistic locations. The location procedure is validated by computing a set of 41 quarry shot solutions and all the results, both about shots and seismic events, are compared with those obtained using the routine location procedure. Results are shown for five contiguous seismotectonic domains, as supported by geological and geophysical evidence (e.g., fault systems, crustal tomography, focal mechanisms types). Earthquake hypocentres are mostly located in the upper crust (0–15 km of depth), in good agreement with thermo-rheological models about the brittle–ductile transitions (8–9 km of depth) and total crustal strengths (1.0–2.0 TN m − 1 ). Epicentres are clustered and/or aligned along present-day active geological structures. The proposed seismotectonic model shows dominant compression along the Giudicarie and Belluno–Bassano–Montello thrusts, with strain partitioning along the dominant right-lateral strike-slip faults of the Schio–Vicenza domain. The present-day deformation of the Southern Alps and the internal Alpine chain is compatible with Adria indentation and the related crustal stress distribution.

In the Orco Valley, inside the Gran Paradiso Massif, 3 main fault systems are present: ( a) E–W striking faults dipping at 45–60° to the N, ( b) high-angle NW–SE striking faults, and ( c) high-angle NE–SW to NNE–SSW striking faults. The E–W striking faults and the interposed NW–SE-faults appear to represent a cogenetic structural association related to a larger scale transtensional shear zone, while the NE–SW faults are probably inherited by an older discontinuous deformation stage. Breccia bodies or veins, mostly consisting of carbonate (siderite–ankerite±calcite)+quartz with sulphide–Au mineralisation, recording a multistage mesothermal evolution, occur along both E–W and NW–SE fault systems. Three water types are recognised: type I, Ca 2+ –HCO 3 − waters, with minor SO 4 2− ; type II, (Ca 2+ /Na + )–HCO 3 − waters varying towards Na + –(HCO 3 − /Cl − ) waters; and type III, Mg 2+ –HCO 3 − waters. Type I and type III groundwaters are freshly recharged waters, only slightly exchanged with rocks. Type II includes waters which come into contact with carbonate fracture fillings, and geochemical modelling indicates that dissolution of carbonates along fractures is the main process controlling the groundwater chemistry. These waters evolve in a system open to uprising CO 2 , and their strongly negative δ 13 C CO 2 suggests a substantial organic component in the CO 2 discharge. In the past, CO 2 -bearing fluids were likely responsible for the formation of Fe-bearing carbonate fracture fillings. The persistence through time of the CO 2 flux in the region has important implications for the reconstruction of the Alpine tectonic evolution and deep structure.

International audience; The Western Alps are among the best studied collisional belts with both detailed structural mapping and also crustal geophysical investigations such as the ECORS and EGT seismic profile. By contrast, the present-day kinematics of the belt is still largely unknown due to small relative motions and the insufficient accuracy of the triangulation data. As a consequence, several tectonic problems still remain to be solved, such as the amount of N-S convergence in the Occidental Alps, the repartition of the deformation between the Alpine tectonic units, and the relation between deformation and rotation across the Alpine arc. In order to address these problems, the GPS ALPES group, made up of French, Swiss and Italian research organizations, has achieved the first large-scale GPS surveys of the Western Alps. More than 60 sites were surveyed in 1993 and 1998 with a minimum observation of 3 days at each site. GPS data processing has been done by three independent teams using different software. The different solutions have horizontal repeatabilities (N-E) of 4-7 mm in 1993 and 2-3 mm in 1998 and compare at the 3-5-mm level in position and 2-mm/ yr level in velocity. A comparison of 1993 and 1998 coordinates shows that residual velocities of the GPS marks are generally smaller than 2 mm/yr, precluding a detailed tectonic interpretation of the differential motions. However, these data seem to suggest that the N-S compression of the Western Alps is quite mild (less than 2 mm/yr) compared to the global convergence between the African and Eurasian plate (6 mm/yr). This implies that the shortening must be accomodated elsewhere by the deformation of the Maghrebids and/ or by rotations of Mediterranean microplates. Also, E-W velocity components analysis supports the idea that E-W extension exists, as already suggested by recent structural and seismotectonic data interpretation.

Deglaciated areas in the valleys of the Italian Alps have recently exhibited a high potential for geomorphologic hazards from diffuse deep-seated gravitational deformations (DSGSDs), caused by rock-mass creep processes that can evolve into rock falls and rock avalanches. A multidisciplinary approach that integrated geomorphologic surveys and stress–strain numerical simulations was used to investigate the effects of the stress release that was induced by the Last Glacial Maximum (LGM) in the Adame Valley (Italian Alps). No evidence of DSGSDs has been found in this area; however, data are available to develop a well-constrained evolutionary model of the valley deglaciation. The extent and thickness of the southern extension of the Adamello glacier (the widest glacier in Italy) during its primary growth phases, including those of the LGM, three Late Glacial stages and the Little Ice Age (LIA) were reconstructed using glacial geological surveys and were reproduced using a finite-difference stress–strain sequential model spanning from the LGM to the present. A thermomechanical numerical configuration was developed based on geomechanical field measurements that were collected from rock outcrops and data from laboratory tests, specifically performed on intact rock samples. The numerical simulations demonstrate that thermomechanical viscous behaviour cannot be neglected because the resulting strains on the slopes are significantly higher than those resulting from conventional elastoplastic behaviour. The last major thermal effect in the rock masses reproduced using the model occurred from 11.5 ka until the LIA; the resulting displacement rates are as much as several tens of mm/ka, which are consistent with the absence of DSGSDs in the Adame Valley, as these rates are significantly lower than those previously obtained from DSGSDs and other large landslides in the Alps. Based on thermomechanical numerical solutions, these rates should persist for the next 1000 years assuming that no variations in current climatic conditions occur.

Purpose: Climate change is driving strong variations in mountain habitats, such as glacier retreat, which is releasing large surfaces soon colonized by vegetation and attacked by weathering and pedogenesis. Many proglacial soil chronosequences have been studied in different parts of the world, but no study is available on early soil development and pedogenesis on serpentinite. Materials and methods: We analysed the development of the main chemical (pH, organic matter, nutrients and exchangeable cations) and morphological properties in three soil chronosequences in the Verra Grande Glacier forefield (Italian side of the Monte Rosa Group, Western Alps), characterized by slightly different parent materials (pure serpentinite or serpentinite with small gneiss inclusions) and topography (steep lateral moraines or flat basal till). Results and discussion: Organic matter accumulation, acidification and base and metal leaching are the most important pedogenetic processes active during early stages of soil formation on serpentinite in the upper subalpine altitudinal belt. These processes are associated with minor changes in color and structure showing weak mineral weathering. Biocycling of nutrients is limited on pure serpentinite because of weak primary productivity of the plant community. Pedogenesis is quite slow throughout the forefield, and it is slowest on pure serpentinite. On flat surfaces, where slow erosion permits a fast colonization by Ericaceae, the podzolization process begins after few centuries since moraine deposition, while on steep slopes more time is required. Conclusions: Pedogenesis on serpentinite is extremely slow. The fast colonization by grassland species increases the speed of pedogenetic trends where serpentinitic till is enriched by small quantities of P-rich gneiss. The encroachment of forest-shrub species increases the speed of pedogenetic trends thanks to a strong nutrient biocycling.

Field observations, old terrestrial photographs and maps, aerial orthophotos and detailed geomorphological mapping were used for compiling and validating a 119‐year cumulative record of terminus ch...

This paper discusses the Holocene evolution of two sites in the Central Italian Alps, the Foscagno Valley and the Stelvio–Livrio area, in terms of the interaction between permafrost distribution and glacial history. The applicability of phytosociological vegetation survey to investigate recent glacial evolution where geomorphological evidence is poor or totally absent is also illustrated. Bottom temperature of snow measurements and detailed geomorphologic survey and air-photo interpretation were carried out in the Stelvio–Livrio area. Boreholes were drilled in each site, one (24 m deep) in the Foscagno rock glacier (2510 m ASL), the second (100.3 m deep) in dolostone-limestone bedrock at the Stelvio Pass (3000 m ASL). The latter borehole is a component of the PACE European Permafrost Monitoring Network. In Foscagno Valley, the formation of permafrost during a cold and dry phase of the Holocene allowed the preservation of an ice body which otherwise would have disappeared. More recently, a Little Ice Age glacier advance, whose exact location and extension were defined by means of the analysis of vegetal associations, induced some degradation in the permafrost. In the Stelvio–Livrio area, a cold-based glacier apparently had much less influence on the local permafrost evolution and thermal regime. Copyright © 2001 John Wiley & Sons, Ltd. RESUME L'evolution holocene de deux sites des Alpes centrales italiennes, la vallee de Foscagno et la region de Stelvio-Livrio, est discutee pour contribuer a la comprehension des relations entre la distribution du pergelisol et l'histoire glaciaire. Un autre but de l'etude etait de verifier la possibilite d'utiliser des releves phytosociologiques pour comprendre l 'evolution recente glaciaire de zones ou des evidences geomorphologiques sont maigres ou totalement absentes et de mieux comprendre ainsi la distribution du pergelisol. Des mesures BTS, des leves geomorphologiques detailles et des interpretations de photos aeriennes de la zone Stelvio-Livrio ont ete realises. Enfin, deux sondages ont ete implantes : l'un (24 m de profondeur) dans le glacier rocheux de Foscagno (2510 m) et l'autre dans le substratum rocheux (100.3 m de profondeur) du Col du Stelvio (3000 m). Ce dernier sondage fait partie du reseau europeen PACE de surveillance du pergelisol. Des leves phytosociologiques ont ete realises dans les deux zones. Dans la vallee de Foscagno, la formation du pergelisol pendant une phase froide et aride de l'Holocene a permis la conservation d'un corps de glace qui, autrement, aurait disparu. Plus recemment, une avancee glaciaire pendant le Petit Age Glaciaire (dont la localisation et l'exacte extension ont ete reconnues par les etudes phytosociologiques) a provoque la degradation du pergelisol. Dans la zone de Stelvio-Livrio, un glacier a base froide a apparemment beaucoup moins influence la distribution du pergelisol et son regime thermique. Copyright © 2001 John Wiley & Sons, Ltd.

This paper describes the recent evolution of Italian glaciers through an analysis of all available terminus fluctuation data that the authors have entered in a glaciers database (named GLAD) containing 883 records collected on glaciers from 1908 to 2002. Furthermore, a representative subset of data (249 glaciers located in Lombardy) was analysed regarding surface area changes. For the analysis of terminus fluctuations, the glaciers were sorted by size classes according to length. The data showed that during the 20th century Italian Alpine glaciers underwent a generalized retreat, with one distinct and well documented readvance episode that occurred between the 1970s and mid-1980s, and a poorly documented one around the early 1920s. The rates of terminus advance and retreat have changed without significant delays for the larger glaciers with respect to the smaller ones. However, the smaller the glacier, the more limited the advance (if any) during the 1970s and early 1980s. The behaviour of glaciers shorter than 1 km appears to have changed in the last decade, and between 1993 and 2002 they retreated at a very high rate. The analysis of the subset of data led to a quanti-fication of surface reduction of c. 10% from 1992 to 1999 for glaciers in Lombardy. Small glaciers proved to contribute strongly to total area loss: in 1999, 232 glaciers (c. 90% of the total) were smaller than 1 km2, covering 27.2 km2 (less than 30% of the total area), but accounted for 58% of the total loss in area (they had lost 7.4 km2).

A detailed engineering geological characterization and performance monitoring were carried out at the site of an underground powerhouse cavern in the Italian Alps. In the area of the hydroelectric project, consisting of a 4-m diameter and 10-km-long diversion tunnel and a powerhouse cavern (20 m wide, 39 m long and 30 m high), metamorphic anisotropic rocks, are present. A pervasive foliation, whose trend describes an open fold at the cavern site, characterizes the geological structure. The studies include petrographic analyses and geo-mechanical properties of the rocks, in situ stress measurements and rock-mass classifications for the cavern site as well as the surrounding area. Based on field investigations, two numerical models (FEM and DEM codes) were used to investigate the overall stability of the excavation and to predict the expected deformation caused by each excavation phase. The measurements of actual deformations, by multi-base extensometer data, are reasonably close to those predicted through the numerical approaches.

Debris flows pose major hazards in many mountainous regions. The most apparent influence of climate changes on debris flows is related to variations in the precipitation regime. In glacial and periglacial areas, also glacier retreat and permafrost degradation have a major role in debris flow occurrence, as they can substantially increase the availability of erodible debris and provide the conditions for sudden water release. The paper analyses some recent debris flows in periglacial environments in the Italian Alps. The study is based on field observations and on the comparison of present geomorphic conditions with those that existed before the glacial retreat of the last decades. The results of researches on climate changes in Italy indicate that the studied debris flows occurred in the frame of a general trend of increasing temperature. In this context, debris flows in periglacial areas should be viewed as a particular aspect of geomorphological and hydrological changes driven by climate changes in alpine headwaters. Most of studied debris flows have been caused by rainfall. In these cases, the influence of cryosphere degradation essentially consists in an increased availability of mobilisable material. Other processes, which trigger debris flows in areas affected by glacial shrinkage, are glacial lake outbursts and the melting of ground-buried ice.