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Landslides and in particular the temporal concentrations of instability events in different periods of the Holocene have not been by now considered as climate proxies, though they could improve significantly the insight of the environmental context as a whole in the reconstructions of past climate changes. The key to answer the questions concerning how and why climate has varied on different time-scales is infact to improve the documentation and understanding of natural variability for periods extending back beyond the instrumental record. Knowledge of past climate changes has to be gained from well-calibrated proxy data derived from different natural archives. These archives should provide accurate records of climate history, should be dated with annual precision on a calendar year time-scale and correlated through time. Actually, no single archive encompasses such properties and information from different sources are to be merged. In this framework, when the geomorphological evolution of a slope can be described by way of surveys, radiometric dating, cross-sections etc., and climate is considered to be the main cause of instability, concentrations of events become significant in a paleoclimatic perspective, if a sufficient number of landslides have been recorded. The records of landslide activity are not likely to be considered as comprehensive proxy archives, but they can give a significant contribution to the establishment of a paleoclimatic multi-proxy database when the environmental context is analysed with a multidisciplinary approach. Within the research carried out in the Dolomites (Italy), the event statigraphy of past landsliding has been traced thanks to the availability of sections and boreholes in which a large number of organic matter samples has been collected and dated with the radiocarbon method. During the Holocene, notwithstanding the evident influence of the geological-structural factors on slope modelling in the study areas, a possible cause-effect relationship between the phases of active slope movements and climatic and environmental changes taking place from the Lateglacial to date can be inferred. A period of enhanced slope instability has been found at the beginning of the Holocene, in the Preboreal and Boreal some 11,500 to 8500 cal yr BP, that reflects the response of the slope-system to the changes in the environmental forcing processes. The retreat of LGM glaciers made the valley flanks sensitive and susceptible of rapid changes and prone to an accelerated geomorphic activity. The response of the slope-system consisted on large rock slides, affecting the dolomite slopes after the withdrawal of Würm glaciers and on complex movements (rotational slides and flows) involving the underlying pelitic formations. A second concentration of landslide events in this area is reported during the Subboreal period (some 5800 to 2000 cal yr BP), when rotational slides and flows mainly took place. The slope movements ascribed to this second phase may likely be considered as reactivations of more ancients events, linked to a humid phase. In any case, the correlation of landslide activity records with the environmental context deduced from other proxies and confirmed by a multidisciplinary approach can validate the assumption that the process of landsliding is an expression of slope-system sensitivity to climate changes.

Landslides are widespread along the north-western coast of the Island of Malta and are strictly linked to the structural setting. Exemplary cases of rock spreading and block sliding phenomena characterise this stretch of coast. They are favoured by the overposition of two different geological units widely outcropping there, the Blue Clay Formation and the Upper Coralline Limestone Formation. The latter forms a wide plateau, bordered by vertical cliffs. At the foot of the cliffs, clayey terrains crop out and develop gentle slopes covered by large blocks detached and moved by rock spreading and block sliding phenomena. These mass movements are favoured by the fragile behaviour of limestones, which cap clays, otherwise characterised by visco-plastic properties. In order to investigate the kinematics and the evolution of these types of coastal landslides, a multidisciplinary and multitechnical approach was applied on a study site, named Il-Prajjet, which provides a spectacular case of rock spreading evolving into block sliding. This paper illustrates the results achieved by means of different engineering geological and geophysical techniques allied with traditional detailed geomorphological survey and mapping. In particular, the surface displacements of the landslides were determined using long-term GPS observations, acquired approximately every 6 months, over a 4.5-year period. A network of GPS benchmarks were distributed on the edge of a limestone plateau affected by rock spreading and on a series of displaced blocks making up a large block slide, finally enabling the definition of the state of activity and the rates of movement to be performed. In addition, the results deriving from two continuous fissurimeters more recently installed at the edge of two persistent joints over the block sliding area are outlined, with reference to the correlation between variations of crack apertures and precipitation input. In order to identify main structural discontinuities and to reconstruct variability of underground surface contact between clays and overlying limestones, Resistivity Tomography profiles and GPR investigations were carried out. Finally, the results obtained by combining the outputs of geophysical surveys and different field monitoring activities can be considered a first step on which numerical models can be developed and validated, in order to assess landslide hazard and risk of this stretch of Maltese coastline.

Malta and Sicily show common geological and geomorphological features, having been also physically linked not later than the Last Glacial Maximum. At present both islands have a high tourist vocation, but their environmental potential is not fully exploited for attracting tourists and visitors. In the framework of an international research project, “Ecological Cross-border Networks Malta-Sicily” (RE.MA.SI.), a multidisciplinary study for the identification, selection and enhancement of geosites in the Maltese and Sicilian islands was carried out. A number of sites both in Malta and Sicily have been identified and qualitatively and quantitatively assessed applying a methodology already tested in previous studies. The aim was to see whether any of these sites could be considered as geosites of geomorphological interest (geomorphosites) according to scientific, additional and use values. In order to create a common geomorphosite inventory and a GIS-database, the standard forms of the Italian Institute for Environmental Protection and Research (ISPRA) were used. The recognised and assessed geomorphosites mainly include coastal and kart features, but also landslides, badlands and mud volcanoes are encountered due to their scientific interest and scenic value. The research enabled us to highlight that geomorphosites can become a relevant resource for social and economic development in Malta and Sicily, and can provide the ground for bridging these islands through a new integrated approach with foresees common methods and actions for geoheritage exploitation and enforcement of conservation strategies.

La valle del Rio della Rocca nel Comune di Castellarano (Reggio Emilia) è stata interessata a partire dagli anni ‘50 del secolo scorso da attività estrattive che in parte ne hanno profondamente modificato le caratteristiche ambientali, in particolare quelle geomorfologiche. In considerazione dell’interesse paesaggistico della valle e ai fini di una riqualificazione ambientale del territorio, è stato realizzato uno studio multidisciplinare volto a delineare i principali aspetti geologici, paleontologici, floristici e faunistici. Specifica attenzione è stata posta alla valutazione dell’instabilità dei versanti e alla individuazione dei geositi presenti nell’area. Sulla scorta dei risultati delle ricerche effettuate sono state elaborate proposte di riqualificazione del territorio che prevedono una valorizzazione della valle a fini geoturistici e ricreativi. Since the mid-1950s the small catchment of Rio della Rocca, in the municipality of Castellarano (northern Italy), has been affected by quarrying activities which in some places have deeply changed its environmental and, in particular, geomorphological features. Considering the high scenic and environmental value of the study area, multidisciplinary investigations concerning the main geological, botanical and faunistic aspects were carried out in order to plan the environmental upgrading of the whole valley. Specific attention was given to assessing slope instability and identifying the geosites of the area. On the basis of the results attained, proposals of territorial upgrading have been developed which take into account also appraisal measures for geotourism and recreational purposes.

Climate change refers to a statistically significant variation in either the mean state of the climate or in its variability, persisting for an extended period, typically decades or longer. Climate change on Earth may be due to natural internal processes or external forcing, or to persistent anthropogenic perturbation of the composition of the atmosphere or of land use. The Fourth Assessment Report of the Intergovernmental Panel on Climate Change states that the warming of the climate system is unequivocal. Moreover, there is a high level of confidence that this warming is a result of human activities releasing greenhouse gases to the atmosphere from the burning of fossil fuels, deforestation and agricultural activities. A range of future greenhouse gas emission scenarios are also presented, based on estimates of economic growth, technological development and international cooperation. In all scenarios temperatures continue to rise worldwide, with global mean temperatures averaging plus 2 to 4 °C by the end of the century, accompanied by changes in the amounts and patterns of precipitation. The predicted rate of warming seems to be faster than ever recorded and in particular over the last 2000 years, and also since the Earth was exiting the Little Ice Age. There will also be an increase in the frequency and intensity of extreme temperature and precipitation events at any time of the year, regardless of the season. If the evidence of climate change is unequivocal, is climate change triggering more landslides, or will it in the future? Intuitively, yes: climate changes have the potential to modify the stability of slopes, both natural and constructed. This issue is important and urgent, no matter what are the actual causes of climate changes. It has been proved that most landslides are caused by saturated soil moisture conditions and by loss in soil strength, triggered by climatically-controlled processes, such as intense and/or prolonged precipitation events, rapid snowmelt, glacier thinning, permafrost degradation or river migration, depending on geomorphological settings. If climate change leads to increased frequency and/or magnitude of these events and processes, the frequency and/or magnitude of landslides in a region will be similarly influenced. Thus, we can expect more instability, as a consequence of the increasing number of short but intense events, as well as by increasing cumulative rainfall etc. Although the frequency and/or magnitude of landslides may increase with the anticipated climate change, the regional distribution of landslides is not expected to change significantly, as many of the primary factors controlling landslide susceptibility, such as geology, physiography and slope, are remaining relatively constant. Potentially unstable areas, however, could for example include slopes presently underlain by degrading permafrost. A sort of domino effect may also be expected: increased landslide activity may lead to increased sediment loads and channel instability in rivers. Currently, where the best practice in landslide risk mitigation is established, the design and management of infrastructure and urban assets affected by natural slope instability is carried out on the basis of specified standards and guidelines that assume static environmental conditions. However, the rate of dominant input parameters (i.e., precipitation and temperature) is now clearly changing. Hence, a review of this approach is demanded, as the assumption of a steady climate state can be misleading. However, such impacts are currently speculative and will be difficult to unravel from “pure” anthropogenic effects, in some case driven by climate changes themselves. Accordingly, compound effects of climate change and other human actions (where humans are both co-triggers and element at risk) must be accounted for. In this sense, some studies seem to highlight the fact that climate change is important, but land use change is even mor...

This study concerns the relationships between climate changes and hillslope evolution during the Late Quaternary, with particular attention to landslide processes. The research has been carried out in test areas located in the Dolomites (Italy), following the basic idea that modifications in landslide frequency may be interpreted as changes in the hydrological conditions of the slopes, which are in turn controlled by climate. By analysing a large data set, consisting of 75 radiocarbon dates, obtained with reference to 24 landslides, temporal clustering of dated mass movements have been observed, that is a necessary condition to look for possible causes of past activity periods. By analysing the data set, four periods of enhanced landsliding have been outlined. These four periods have been compared with different Late Glacial and Holocene paleoclimatic records, in order to check the correspondence between temporal concentrations of landslide events and climatic events. Besides the intrinsic difficulties in the correlation among these records, which are mainly due to different spatial scales (local, regional and global), to dissimilar time-resolutions and dating constraints, remarkable evidence comes forward. The periods of enhanced slope instability in the Dolomites display a quite good correlation with cold and humid phases. At the same time, also periods of dry climate have a clear influence on landslide activity, resulting in gaps in the time series. The results suggest that landslide activity could have been climatically-driven and that, in particular, a positive moisture balance could have played a major role in conditioning slope instability at the hundred to thousand years time scale.

The paper first introduces the main geological and geomorphological features of the Italian Dolomites which make the region a geoheritage high-altitude field “laboratory” and an outstanding example of geodiversity. Then landslides, which represent a topical aspect of the complex Lateglacial and Holocene geomorphological evolution of the region, are described with special emphasis on their temporal distrubution and type. Finally, it is shown how the widespread presence of landslides through time and space has contributed to the geodiversity of the region, enhancing also its geoheritage value.

This study concerns the relationships between climate changes and hillslope evolution during the Late Quaternary, with particular attention to landslide processes. The research has been carried out in test areas located in the Dolomites (Italy), following the basic idea that modifications in landslide frequency may be interpreted as changes in the hydrological conditions of the slopes, which are in turn controlled by climate. By analysing a large data set, consisting of 75 radiocarbon dates, obtained with reference to 24 landslides, temporal clustering of dated mass movements have been observed, that is a necessary condition to look for possible causes of past activity periods. By analysing the data set, four periods of enhanced landsliding have been outlined. These four periods have been compared with different Late Glacial and Holocene paleoclimatic records, in order to check the correspondence between temporal concentrations of landslide events and climatic events. Besides the intrinsic difficulties in the correlation among these records, which are mainly due to different spatial scales (local, regional and global), to dissimilar time-resolutions and dating constraints, remarkable evidence comes forward. The periods of enhanced slope instability in the Dolomites display a quite good correlation with cold and humid phases. At the same time, also periods of dry climate have a clear influence on landslide activity, resulting in gaps in the time series. The results suggest that landslide activity could have been climatically-driven and that, in particular, a positive moisture balance could have played a major role in conditioning slope instability at the hundred to thousand years time scale.

The AMIS project (Algerian Coast Management through Integration and Sustainability) is implemented by CIRSA (Italian Interdepartmental Centre for Environmental Sciences Research), IMELS (Italian Ministry for Environment, Littoral and Sea) and the APPL (Agence Urbaine chargée de la Protection et de la Promotion du littoral et des zones touristiques de la Wilaya d’Alger). The project aims at supporting national efforts in promoting sustainable use of coastal resources in Algeria and simultaneously contributes to the protection of the environment and sounder development of coastal zones in the Mediterranean by developing an Integrated Coastal Zone Management (ICZM) pilot plan for the two municipalities of Réghaïa and Heraoua located in the eastern part of the Wilaya d’Alger, that includes also the Ramsar site of Lac de Réghaïa.

A conclusione della convenzione di ricerca con il comune di Corvara in Badia e con la Provincia Autonoma di Bolzano, vengono presentati i risultati, con particolare riferimento ai possibili interventi di mitigazione della pericolosità indotta dalla frana di Corvara in Badia

In this Progress Report (January 2005) the work carried out in WP7 is delineated.

Lo studio delle frane costituisce un campo di applicazione di notevole interesse, in cui il contributo del geomorfologo è certamente indispensabile. Alcune monografie recenti trattano diffusamente dell’individuazione e della caratterizzazione delle frane, nonché della valutazione del rischio da frana, illustrando anche misure di mitigazione (Vallario, 1992; Amanti e al., 1996; Dikau e al., 1996b; Glade e al., 2005). A queste si rimanda per un trattazione dettagliata dell’argomento, mentre nel presente capitolo si intende fornire un quadro aggiornato dal punto di vista concettuale e terminologico relativamente alle cause dell’instabilità dei versanti e alla loro caratterizzazione tipologica e morfologica, facendo riferimento agli standard utilizzati sia a livello internazionale, che dal Servizio Geologico Nazionale (SGN ora confluito in Agenzia per la Protezione dell'Ambiente e per i Servizi Tecnici, APAT). Infine verranno introdotte le problematiche relative alla pericolosità e al rischio da frana e illustrate le più comuni ed efficaci misure di mitigazione. È indubbio che gli eventi franosi possano rappresentare un serio rischio per l’uomo e le sue attività, tuttavia spesso viene posta maggiore enfasi su altri tipi di pericolosità naturali, quali quella sismica o vulcanica, che in termini mediatici risultano certamente più impressionanti e spettacolari. Si è calcolato che siano circa 225.000 le persone che ogni anno perdono la vita a causa di eventi naturali (Burton e al., 1978); tra queste un numero rilevante è dovuto ad eventi di frana collegati anche a terremoti, eruzioni vulcaniche e uragani, che ne costituiscono la causa innescante. Un caso significativo è quello dell’enorme valanga di detrito che si mobilizzò a partire dalla vetta settentrionale del Nevado Huascarán (Perù), in occasione di un terremoto, nel 1970: quasi un terzo delle 70.000 vittime furono letteralmente sepolte dai detriti (Plafker e Ericksen, 1978). In termini di danni socio-economici, inoltre, non debbono essere sottovalutati i numerosi e ricorrenti fenomeni franosi di piccole e medie dimensioni che a lungo termine possono causare maggiori danni (sia diretti che indiretti) di quelli di grandi dimensioni.

Il territorio italiano è diffusamente interessato da fenomeni franosi di varia tipologia e dimensione, la cui distribuzione geografica è strettamente correlata alle caratteristiche geologiche e morfologiche dei versanti, alle vicende tettoniche che questi hanno subito durante il recente sollevamento delle Alpi e degli Appennini e alle condizioni climatiche che caratterizzano la nostra penisola. Nella tavola vengono illustrati grandi movimenti franosi di varia tipologia che hanno determinato la formazione di grandi accumuli, ben riconoscibili tanto sul terreno quanto sulle carte topografiche.

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This paper presents the results of geomorphological investigations carried along the north-western coast of the Island of Malta. Field surveys, accompanied by aerial photo-interpretation, have led to the production of a geomorphological map at 1:7500 scale which outlines the main processes and related landforms. The latter are the results of the complex interplay of structural, gravitational, coastal and karst processes. Particular attention was devoted to the recognition, identification and mapping of landslides which affect large coastal sectors of the study area, locally giving rise to hazardous conditions.

Context: Hydrides of the most abundant heavier elements are fundamental molecules in cosmic chemistry. Some of them trace gas irradiated by UV or X-rays. Aims: We explore the abundances of major hydrides in W3 IRS5, a prototypical region of high-mass star formation. Methods: W3 IRS5 was observed by HIFI on the Herschel Space Observatory with deep integration (about 2500 s) in 8 spectral regions. Results: The target lines including CH, NH, H3O+, and the new molecules SH+, H2O+, and OH+ are detected. The H2O+ and OH+ J=1-0 lines are found mostly in absorption, but also appear to exhibit weak emission (P-Cyg-like). Emission requires high density, thus originates most likely near the protostar. This is corroborated by the absence of line shifts relative to the young stellar object (YSO). In addition, H2O+ and OH+ also contain strong absorption components at a velocity shifted relative to W3 IRS5, which are attributed to foreground clouds. Conclusions: The molecular column densities derived from observations correlate well with the predictions of a model that assumes the main emission region is in outflow walls, heated and irradiated by protostellar UV radiation., Comment: Astronomy and Astrophysics Letters, in press

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In this paper we present the research which is being undertaken to monitor lateral spreading phenomena along the north-west coast of Malta using the GPS technique