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Rockfalls are one of the most common instability processes in high mountains. They represent a relevant issue, both for the risks they represent for (infra) structures and frequentation, and for their potential role as terrestrial indicators of climate change. This study aims to contribute to the growing topic of the relationship between climate change and slope instability at the basin scale. The selected study area is the Bessanese glacial basin (Western Italian Alps) which, since 2016, has been specifically equipped, monitored and investigated for this purpose. In order to provide a broader context for the interpretation of the recent rockfall events and associated climate conditions, a cross-temporal and integrated approach has been adopted. For this purpose, geomorphological investigations (last 100 years), local climate (last 30 years) and near-surface rock/air temperatures analyses, have been carried out. First research outcomes show that rockfalls occurred in two different geomorphological positions: on rock slopes in permafrost condition, facing from NW to NE and/or along the glacier margins, on rock slopes uncovered by the ice in the last decades. Seasonal thaw of the active layer and/or glacier debutressing can be deemed responsible for slope failure preparation. With regard to timing, almost all dated rock falls occurred in summer. For the July events, initiation may have been caused by a combination of rapid snow melt and enhanced seasonal thaw of the active layer due to anomalous high temperatures, and rainfall. August events are, instead, associated with a significant positive temperature anomaly on the quarterly scale, and they can be ascribed to the rapid and/or in depth thaw of the permafrost active layer. According to our findings, we can expect that in the Bessanese glacierized basin, as in similar high mountain areas, climate change will cause an increase of slope instability in the future. To fasten knowledge deepening, we highlight the need for a growth of a network of high elevation experimental sites at the basin scale, and the definition of shared methodological and measurement standards, that would allow a more rapid and effective comparison of data.

Earth's climate is warming and will continue to warm as the century progresses. High mountains and high latitudes are experiencing the greatest warming of all regions on Earth and also are some of the most sensitive areas to climate change, in part because ecosystems and natural processes in these areas are intimately linked to the cryosphere. Evidence is mounting that warming will further reduce permafrost and snow and ice cover in high mountains, which in turn will destabilize many slopes, alter sediment delivery to streams, and change subalpine and alpine ecosystems. This paper contributes to the continuing discussion of impacts of climate change on mountain environments by comparing and discussing processes and trends in the mountains of western Canada and the European Alps. We highlight the effects of physiography and climate on physical processes occurring in the two regions. Processes of interest include landslides and debris flows induced by glacier debuttressing, alpine permafrost thaw, changes in rainfall regime, formation and sudden drainage of glacier- and moraine-dammed lakes, ice avalanches, glacier surges, and large-scale sediment transfers due to rapid deglacierization. Our analysis points out the value of integrating observations and data from different areas of the world to better understand these processes and their impacts.

Air temperature in the European Alps shows warming over recent decades at an average rate of 0.3 °C/10 years, thereby outpacing the global warming rate of 0.2 °C/10 years. The periglacial environment of the Alps is particularly important for several aspects (i.e. hydropower production, tourism, natural hazards, indicator of global warming). However, there is a lack of specific and updated studies relating to temperature change in this environment. In order to fill this gap, the recent temperature trends in the periglacial environment of the Alps were analyzed. Mean/maximum/minimum daily air temperatures recorded by 14 land-based meteorological stations were used, and the temperature indices for the period 1990–2019 were calculated. The periglacial environment of the Alps showed a warming rate of 0.4 °C/10 years, 0.6 °C/10 years and 0.8 °C/10 years for the mean/maximum/minimum temperatures, respectively. These warming rates are higher than that observed for the entire Alpine area. In 2050 many glaciers of the Alps below 3000 m altitude are expected to be extinct, and all the areas previously occupied by glaciers will become periglacial. In order to manage and adapt to these changes, more in-depth climate analyses are needed. This is necessary for all the mountainous areas of the world, which are undergoing similar changes.

For application purposes (in particular water resources management and planning) it is crucial to rely on accurate predictions of the evolution of glaciers on short time scales (from seasonal to multi-annual).This is one of the aims of the MEDSCOPE project in the framework of the ERA4CS initiative: seasonal-to-decadal climate forecasts, produced and downscaled by the project, are used to estimate the evolution of glaciers in selected areas of the Western Italian Alps.For this purpose, empirical glacier models have been calibrated with historical observational data of glacier front fluctuation and mass balance for five glaciers, characterized by different morphology and topoclimatic setting, in the Western Italian Alps. The models will be forced with the seasonal, downscaled forecasts, in order to assess the added value provided by MEDSCOPE to climate services for water management.

Temperature is one of the most important aspects of mountain climates. The relationships between air temperature and rockfalls at high-elevation sites are very important to know, but are also very difficult to study. In relation to this, a reliable method to estimate air temperatures at high-elevation sites is to apply the altitudinal temperature lapse rates (ATLR). The aims of this work are to quantify the values and the variability of the hourly ATLR and to apply this to estimated temperatures at high-elevation sites for rockfalls studies. To calculate ATLR prior the rockfalls, we used data acquired from two automatic weather stations that are located at an elevation above 2500 m. The sensors/instruments of these two stations are reliable because subjected to an accurate control and calibration once for year and the raw data have passed two automatic quality controls. Our study has yielded the following main results: (i) hourly ATLR increases slightly with increasing altitude, (ii) it is possible to estimate temperature at high-elevation sites with a good level of accuracy using ATLR, and (iii) temperature plays an important role on slope failures that occur at high-elevation sites and its importance is much more evident if the values oscillate around 0 °C with an amplitude of ±5 °C during the previous time-period. For these studies, it is not enough to improve the knowledge on air temperature, but it is necessary to develop an integrated knowledge of the thermal conditions of different materials involved in these processes (rock, debris, ice, water). Moreover, this integrated knowledge must be acquired by means of sensors and acquisition chains with known metrological traceability and uncertainty of measurements.

Glaciated and recently (post-Little Ice Age) deglaciated areas are very dynamic environments, undergoing continuous changes, in particular as a consequence of climatic fluctuations and cryosphere changes. The intense geomorphic activity that takes place here conditions natural hazard, sediment transport and tourist fruition. A geo-morphological mapping with applicative purposes has to take into account the peculiarities and the dynamism of these specific areas. We here propose a methodological approach based on the interpretation of a multitemporal set of aerial photos (from 1983 to 2012), in a GIS environment, with application to the sectors modeled by Little Ice Age glaciers in the upper Orco Valley (NW Italy). The result is a geo-morphological map focused on the elements that are most relevant for application purposes, complemented by a map of the spatio-temporal distribution of the natural instability processes identified in the study area for the reference period, aimed to highlight the recent dynamism of the geomorphological elements in the map.

Rockfalls are common instabilities in alpine areas and can cause significant damage. Since high mountains have been affected by an increasing number of these phenomena in the last years, a possible correlation with permafrost degradation induced by climate change has been hypothesized. To investigate this topic, a monitoring system, made of 5 triaxial geophones and 1 thermometer, was installed in 2007 at the Carrel hut (3829 m a.s.l., Matterhorn, North-western Alps), in the frame of the Interreg IIIA Alcotra project n. 196 "Permadataroc". The preliminary data processing relates to the classification of recorded signals, the identification of the significant microseismic events and the analysis of their distribution in time and space. The first results indicated a possible correlation between clusters of events and temperature trend, and a concentration of events in specific sectors of the rock mass. Research is still in progress. The recording of data for a longer period is planned to fully understand seasonal trends and spatial distribution of microseismic activity, and possible relations with permafrost degradation. Nevertheless, the preliminary observations prove that the monitoring system can detect noises generated by rock slope deformation. Once fully developed, this technique could become a helpful tool for early warning and preliminary stability assessments.

Glaciated mountains of the Valle d’Aosta and Piemonte regions are described in relation to the geological, geomorphological and climatic settings of the Western Alps. A comprehensive view of the present-day Alpine regional cryosphere is offered, and links to regional and local examples of its evolution through the Quaternary are provided. Pleistocene moraine amphitheatres (Ivrea and Rivoli-Avigliana) of the piedmont area recall the development stages of Alpine glaciology. Major glaciers (Lys, Miage, Belvedere, Rutor and Sabbione) of the highest peaks of the Western Alps (Mt. Bianco, Mt. Rosa) are analysed for their specific scientific, environmental, cultural and economic importance. The distinctive dynamic nature of the glacial landscape is illustrated by examples of active glacial landforms and related slope instability, whose sensitivity to climate changes can increase hazards and risks.

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.

Recent climate changes are increasing the frequency of rock-slope instabilities in the Alpine region. The formation of cracks leading to rockfalls causes a release of energy propagating in form of elastic waves. These latter can be detected by a suitable transducer array together with the vibrations generated by the impact of rockfalls. Geophones are among the most effective monitoring devices to investi-gate both these phenomena. A monitoring system composed by geophones and thermometers was installed at the J.A. Carrel hut (3829 m a.s.l., Matterhorn, NW Alps) in the framework of the Interreg Alcotra projects PERMAdataROC and MASSA by CNR IRPI and ARPA with the financial and logistic support of the Valle d'Aosta Region. The correlation between temperature trends and microseismic events is presented: cold periods characterized by a rapid tempera-ture decrease present higher concentration of microseismic activity. However, not every drop in temperature is associated to microseismic activity, and the identifi-cation of the processes generating microseismic events in occasion of rapid tem-perature decrease is still uncertain. The objective of the ongoing research activity is to analyze in deep the statistical correlation between the number of microseismic records and the temperatures of air and rock in order to investigate the existence of recurrent patterns in the detected signals.

In the framework of the activities of the GeoClimAlp research group (Geomorphological impacts of Climate change in the Alps), a system of databases has been developed for the storage and management of glacial, periglacial and mountain digital resources, related to the Greater Alpine Region in general, and to the North-Western Italian Alps in particular. These resources are historical documents, publications, photos, aerial photographs, antique and recent maps, instrumental and survey data, related to: (i) alpine glaciers; (ii) natural instability processes and landforms in glacial/periglacial areas; (iii) hydro-climatic conditions of the alpine areas. This wealth of knowledge is mainly referred to the last 150 years. The GeoClimAlp digital resources stored in these databases are mainly used to: (i) study the spatial-temporal evolution of alpine glaciers; (ii) study the geomorphological processes, and in particular natural instability, that occur at high altitude (over 2000 m a.s.l.), in particular as a consequence of climate change; (iii) assess the hydro-climatic conditions of the glacial/periglacial and mountain areas; (iv) conduct research on climate change in the alpine environment.

High runout distances characterize landslides falling on glaciers because of (1) low friction offered by ice to sliding and (2) complex rock-ice interactions that take place during mass motion. Block-fall models (two (2D) and three dimensional (3D)) were tested on the 1936 Felik landslide (Mount Rosa Massif). Geotechnical parameters were assessed through a back-analysis aided by field surveys, aerial photo and historical data analysis. Outcomes are verified for two rock-ice avalanches which ran along the Brenva Glacier (Mount Blanc Massif) in 1920 and 1997. Empirical models show poor precision (75%). 3D numerical models are too complex but 2D ones gave results that pointed out that real runouts exceed predicted ones by 30%, possibly due to fluidization processes. Rock-ice avalanches require attention because they originate in areas likely destined to experience permafrost degradation and glacier retreat. Copyright © 2002 John Wiley & Sons, Ltd.

One of the impacts of climate warming in recent years is the evident increase of the number of rock fall occurrences at high elevations. With few exceptions, these events have small magnitudes and thus are rarely reported and documented, even less so in the past. Therefore it is difficult to use a statistical approach to analyze of the relationships between climate warming and rock slope instability. On the other hand, it is often difficult to carry out a time analysis of meteorological conditions responsible for rock fall triggering, considering that very few automatic weather stations (AWS) are located in the areas and in the altitudinal range that are affected by cryosphere degradation (i.e. above c.a. 3,000 m elevation in the Alps), and that climatic conditions in high elevation environments are spatially and temporally variable. The present study addresses the above-mentioned issues through analysis of a series of small rock falls that occurred in the last 10 years on the Matterhorn and surrounding rock slopes. A specific focus is temperature: we present a preliminary analysis of the spatial and seasonal variability of the vertical temperature gradient in the Conca di Cervinia, where the Matterhorn is located, to illustrate the uncertainty in estimates of the thermometric conditions at high elevation rock fall sites.

The cryosphere is especially sensitive to the fluctuations of climatic parameters, and specifically to ongoing global warming. Mountain glaciers, in particular, are good indicators of climatic trends, as they have response times to climate forcing which are intermediate between snow (which responds mainly to short-term climate forcing) and permafrost/ground ice, whose response is delayed in time and conditioned by a complex ensemble of factors. When studying glacier response to climate change, the main objectives are: (i) understand the terrestrial, local impacts of global climatic changes, (ii) develop scenarios of the future evolution of glaciated areas, according to the available global climatic projections. This two objectives have both scientific and applied merits. The latter are related to the importance of glaciers in the water cycle, in sediment fluxes, and as a source of natural hazards. The combination of historical and geomorphological information with numerical models of climate systems and glacier response to climate forcing is one of the most robust approaches to address the study of glacier evolution in response to climate fluctuations and change. In order to be promptly available for use, historical and geomorphological data (including climatic ones) need to be properly organized in information management systems, which guarantee the preservation and standardization of data, along with their easy processing and retrieval. The present contribution aims at illustrating the experience gained through the application of this multidisciplinary approach to glaciers of the western Italian Alps.

We study the response of a set of glaciers in the Western Italian Alps to climate variations using the minimal glacier modeling approach, first introduced by Oerlemans. The mathematical models are forced over the period 1959–2009, using temperature and precipitation recorded by a dense network of meteorological stations and we find a good match between the observed and modeled glacier length dynamics. Forcing the model with future projections from a state-of-the-art global climate model in the RCP 4.5 and RCP 8.5 scenarios, we obtain a first estimate for the "expiration date" of these glaciers.

In this work, we analyze climate variability and glacier evolution for a study area in the Northwestern Italian Alps from the Little Ice Age (LIA) to the 2010s. In this area, glacier retreat has been almost continuous since the end of the LIA, and many glaciers are now extinct. We compared glaciological and climatic data in order to evaluate the sensitivity of glaciers to temperature and precipitation trends. We found that temperatures show significant warming trends, while precipitation shows no clear signal. After the 1980s, the total number of positive trends in temperature increased, particularly minimum temperature. The latter does not seem to be the only cause of glacier shrinkage but rather on acceleration of an ongoing trend documented since the end of the LIA. In some rare cases, the effects of warming trends on glacier dynamics have been accentuated by a concomitant decrease in precipitation. We hope that this study will contribute to increase the knowledge of the relationships between climate variation and glacier evolution in the Greater Alpine Region.

In early month of November 2007, a 1.4 km debris flow initiated on a steep south-facing slope above Moose Lake in Mount Robson Provincial Park, British Columbia. Snow meltwater was likely concentrated along a shallow seasonally frozen rupture surface, generating high pore water pressure. The debris flow bifurcated into two concentrated gullies before distributing as a debris flood on a snow-covered fan. The debris flow crossed a twin pipeline corridor and came to rest in a ditch against a highway berm. There was no damage to infrastructure. In many ways, the landslide resembles skin flows described in permafrost zones.

The Monte Rosa east face (Macugnaga, Italian Alps) is one of the highest flanks in the Alps. Steep hanging glaciers and permafrost cover large parts of the wall. Since the end of the Little Ice Age (about 1850) the Monte Rosa east face is undergoing a progressive reduction of its ice cover; moreover new instability phenomena related to permafrost degradation and rapid deglaciation have been occurring since over a decade ago. The progressive destabilization of high-mountain faces is a consequence of many factors, such as topography, geological and structural conditions, intense freeze-thaw activity and oversteepened slopes from glacial erosion. Two major events, an ice avalanche occurred in August 2005 and a rock avalanche occurred in April 2007 are briefly described in this paper. In both cases, the accumulation area was located on the Belvedere Glacier at the foot of the Monte Rosa east face. A 3D dynamic model (DAN3D) was applied in order to back analyze the runout of the events, enabling the calibration of the input parameters for the assumed rheological models.

Debris flows from glacier forefields, triggered by heavy rain or glacial outbursts, or clamming of streams by ice avalanches, pose hazards in Alpine valleys (e.g. the south side of Mount Blanc). Glacier-related debris flows are, in part, a consequence of general glacier retreat and the corresponding exposure of large quantities of unconsolidated, unvegetated, and sometimes ice-cored glacial sediments. This paper documents glacier-related debris flows at 17 sites in the Italian, French, and Swiss Alps, with a focus on the Italian northwest sector. For each case data are provided which describe the glacier and the instability. Three types of events have been recognized, based on antecedent meteorological conditions. Type 1 (9 documented debris flows) is triggered by intense and prolonged rainfall, causing water saturation of sediments and consequent failure of large sediment volumes (up to 800000 m 3). Type 2 (2 debris flows) is triggered by short rainstorms which may destabilize the glacier drainage system, with debris flow volumes up to 100000 m(3). Type 3 (6 debris flows) occurs during dry weather by glacial lake outbursts or ground/buried ice melting, with debris flow volumes up to 150000 m(3). A data base of historic cases is needed in order to advance process understanding and modelling, and thus improve hazard assessment. (C) 2007 Published by Elsevier B.V.

Extraordinary development s are taking place at Ghiacciaio del Belvedere near Macugnaga, Valle Anzasca, in the Italian Alps. A surge-type  ow acceleration started in the lower parts of the Monte-Rosa east face, leading to strong crevassing and deformation of Ghiacciaio del Belvedere, with extreme bulging of its orographic right margin. High water pressure and accelerated movement lasted into winter 2001/2002: in places, the ice is now starting to override moraines from the Little Ice Age. In addition, but fairly independently , a most active detachment zone for rock falls and debris  ows has been developing for several years now in the east face of Monte Rosa. Besides the scienti Ž c interest in these separate phenomena, both events affect the growing hazard potentia l to the local infrastructure and must be considered seriously.

The Po Valley brines represent the base level of the Quaternary aquifer located in a thick clay-sands sedimentary sequence. Geochemistry indicates that these are marine waters, evaporated to the stage of gypsum precipitation and trapped at the bottom of the basin in the late Messinian. Most of the groundwater samples collected from different springs and wells in the plain result from a mixture of these Na–Cl brines and shallow groundwaters laterally recharged by the Alpine and Apennine chains. Natural outflows of brackish waters are associated with major tectonic features. Mud volcanoes, located in the eastern sector of the Po plain, are constantly monitored as sudden chemical changes are significant precursors of seismic activity. In the western sector, calcite-filled veins isotopically record different degrees of water-rock interaction. These are outcropping fossil conduits, where mixing between shallow groundwaters and deep seated brines has occurred. The temporal continuity of the hydrological circuits allows the reconstruction of past and present groundwater circulation patterns. This paper summarises and integrates the geochemical data produced over many years in order to obtain a regional picture of brine origins and the natural mechanisms of groundwater flow.