Rescue Emergencies Due to High-Altitude Illnesses Are Rare in Switzerland

Background: Despite a potential high risk of acute mountain sickness (AMS) in the Swiss Alps, there is a lack of analyses concerning its relevance over longer periods. In consequence, the aim of this study is to analyze the prevalence of AMS in comparison to other causes of mountain emergencies in recent years in Switzerland. Material and Methods: Based on the central registry of mountain emergencies of the Swiss Alpine Club (SAC), all cases in the period between 2009 and 2020 were analyzed for AMS including the most severe forms of high-altitude pulmonary edema (HAPE) and high-altitude cerebral edema (HACE). Emergencies were assessed for the severity of the event with a National Advisory Committee for Aeronautics (NACA) score. Results: From a total of 4596 high-altitude mountaineering emergencies identified in the observational period, a total number of 352 cases of illnesses were detected. Detailed analysis revealed 85 cases of AMS, 5 cases of HAPE, and 1 case of HACE. The average altitude was 3845 ± 540 m. Most cases were in the canton of Valais, especially in the Monte Rosa region and the mountains of the Mischabel group (Täschhorn, Dom, Südlenz, Nadelhorn, Hohberghorn). There were only three deaths related to high-altitude illnesses; all the other events could be identified as moderate to severe but not life-threatening. Discussion: An emergency due to AMS that requires rescue is unlikely in the Swiss Alps. This does not imply that AMS is not a concern. However, the facts that the maximal altitude is relatively low and that fast self-descents often seem possible probably minimize the likelihood that mountaineers with symptoms contact emergency services.

Resilience and adaptation to volcanoes in Late Middle Ages in Lipari island (Aeolian, Italy)

Volcanic activity resumed during early Middle Ages times at Lipari following at least 6000 years of quiescence. This phenomenon occurred in a social context that had continuously developed from prehistoric times to the Roman age and was burdened by a demographic crisis that involved the archipelago between the 6th and 11th century AD. The rare archaeological records relating to the 6th - 11th centuries suggest abrupt changes in the population of the islands. The medieval sources are rich in religious and fantastic references to volcanic events linked to Lipari and Vulcano, testifying the uneasy condition for the human communities. This work concerns the resilience and adaptation of the communities to volcanic activity during the Late Middle Ages in Lipari. Starting from 1083 the Aeolian archipelago was involved in a repopulation program, implemented in 1095 by the Constitutum and organized by the Benedictine Monastery with the annexed S. Bartolomeo Cathedral on the castle. From the 13th century the volcanic phenomena, strictly limited to the northern sector of the island, did not interfere as previously with the anthropic activities. The Monastery will be enlarged in the Norman phase during the first half of the 12th century with the construction of the cloister. New historical documents relating to the 1264, report news of fires and land movements on Lipari. Recent age determinations obtained for the obsidian flow of Rocche Rosse at 1220 ± 30 AD (archaeomagnetic dating) and for an obsidian block of the Lami pyroclastic cone at 1243 ± 190 (fission-track dating) allow to define the age of the last phase of activity of the Monte Pilato-Lami-Rocche Rosse complex, and to associate it the events reported on 1264’s historical documents. This work makes in comparison volcanological, archaeological and historical dates and described an updated summary of one of the lesser known phases of the history of the archipelago. The main consequence of the medieval volcanic activity at Lipari caused a clear division of the territory with the population confined in the southeast quadrant, protected to the north by Serra and Monte Rosa which represented a natural orographic barrier.

Alpine peak pressure and tectono-metamorphic history of the Monte Rosa nappe: evidence from the cirque du Véraz, upper Ayas valley, Italy

The Monte Rosa nappe consists of a wide range of lithologies that record conditions associated with peak Alpine metamorphism. While peak temperature conditions inferred from previous studies largely agree, variable peak pressures have been estimated for the Alpine high-pressure metamorphic event. Small volumes of whiteschist lithologies with the assemblage chloritoid + phengite + talc + quartz record peak pressures up to 0.6 GPa higher compared to associated metapelitic and metagranitic lithologies, which yield a peak pressure of ca. 1.6 GPa. The reason for this pressure difference is disputed, and proposed explanations include tectonic mixing of rocks from different burial depths (mélange) or local deviations of the pressure from the lithostatic value caused by heterogeneous stress conditions between rocks of contrasting mechanical properties. We present results of detailed field mapping, structural analysis and a new geological map for a part of the Monte Rosa nappe exposed at the cirque du Véraz field area (head of the Ayas valley, Italy). Results of the geological mapping and structural analysis shows the structural coherency within the western portions of the Monte Rosa nappe. This structural coherency falsifies the hypothesis of a tectonic mélange as reason for peak pressure variations. Structural analysis indicates two major Alpine deformation events, in agreement with earlier studies: (1) north-directed nappe emplacement, and (2) south-directed backfolding. We also analyze a newly discovered whiteschist body, which is located at the intrusive contact between Monte Rosa metagranite and surrounding metapelites. This location is different to previous whiteschist occurrences, which were entirely embedded within metagranite. Thermodynamic calculations using metamorphic assemblage diagrams resulted in 2.1 ± 0.2 GPa and 560 ± 20 °C for peak Alpine metamorphic conditions. These results agree with metamorphic conditions inferred for previously investigated nearby whiteschist outcrops embedded in metagranite. The new results, hence, confirm the peak pressure differences between whiteschists and the metagranite and metapelite. To better constrain the prograde pressure–temperature history of the whiteschist, we compare measured Mg zoning in chloritoid with Mg zoning predicted by fractional crystallization pseudo-section modelling for several hypothetical pressure–temperature paths. In order to reach a ca. 0.6 GPa higher peak pressure compared to the metapelite and metagranite, our results suggest that the whiteschist likely deviated from the prograde burial path recorded in metapelite and metagranite lithologies. However, the exact conditions at which the whiteschist pressure deviated are still contentious due to the strong temperature dependency of Mg partitioning in whiteschist assemblages. Our pseudo-section results suggest at least that there was no dramatic isothermal pressure increase recorded in the whiteschist.

Firn changes at Colle Gnifetti revealed with a high-resolution process-based physical model approach

Our changing climate is expected to affect ice core records as cold firn progressively transitions to a temperate state. Thus, there is a need to improve our understanding and to further develop quantitative process modeling, to better predict cold firn evolution under a range of climate scenarios. Here we present the application of a distributed, fully coupled energy balance model, to simulate cold firn at the high-alpine glaciated saddle of Colle Gnifetti (Swiss–Italian Alps) over the period 2003–2018. We force the model with high-resolution, long-term, and extensively quality-checked meteorological data measured in the closest vicinity of the firn site, at the highest automatic weather station in Europe (Capanna Margherita, 4560 m a.s.l.). The model incorporates the spatial variability of snow accumulation rates and is calibrated using several partly unpublished high-altitude measurements from the Monte Rosa area. The simulation reveals a very good overall agreement in the comparison with a large archive of firn temperature profiles. Our results show that surface melt over the glaciated saddle is increasing by 3–4 mm w.e. yr−2 depending on the location (29 %–36 % in 16 years), although with large inter-annual variability. Analysis of modeled melt indicates the frequent occurrence of small melt events (<4 mm w.e.), which collectively represent a significant fraction of the melt totals. Modeled firn warming rates at 20 m depth are relatively uniform above 4450 m a.s.l. (0.4–0.5 ∘C per decade). They become highly variable at lower elevations, with a marked dependence on surface aspect and absolute values up to 2.5 times the local rate of atmospheric warming. Our distributed simulation contributes to the understanding of the thermal regime and evolution of a prominent site for alpine ice cores and may support the planning of future core drilling efforts. Moreover, thanks to an extensive archive of measurements available for comparison, we also highlight the possibilities of model improvement most relevant to the investigation of future scenarios, such as the fixed-depth parametrized routine of deep preferential percolation.

A local model of snow-firn dynamics and application to Colle Gnifetti site

The regulating role of glaciers on catchment run-off is of fundamental importance in sustaining people living in low lying areas. The reduction in glacierized areas under the effect of climate change disrupts the distribution and amount of run-off, threatening water supply, agriculture and hydropower. The prediction of these changes requires models that integrate hydrological, nivological and glaciological processes. In this work we propose a local model that combines the nivological and glaciological scales. The model describes the formation and evolution of the snowpack and the firn below it, under the influence of temperature, wind speed and precipitation. The model has been implemented in two versions: (1) a multi-layer one that considers separately each firn layer, and (2) a single-layer one that models firn and underlying glacier ice as a single layer. The model was applied at the site of Colle Gnifetti (Monte Rosa massif, 4400–4550 m a.s.l.). We observed an average reduction of annual snow accumulation due to wind erosion of 2 · 103 kg m−2 y−1 to be compared with a mean annual precipitation of about 2.7 · 103 kg m−2 y−1. The conserved accumulation is made up mainly of snow deposited between April and September, when temperatures above melting point are also observed. End of year snow density, instead, increased in average of 65 kg m−3 when the contribution of wind to snow compaction was added. Observations show a high spatial and interannual variability in the characteristics of snow and firn at the site and a correlation of net balance with radiation and number of melt layers. The computation of snowmelt in the model as a solely function of air temperature may therefore be one of the reasons of the observed mismatch between model and observations.

Considerazioni tassonomiche su Pterostichus (Oreophilus) flavofemoratus (Dejean, 1828) e P. (O.) pinguis (Dejean, 1828) (Coleoptera Carabidae Pterostichini)

Sulla base dell’analisi dei caratteri morfologici esterni e dei genitali maschili di numerosi individui distribuiti sull’intero areale, Pterostichus pinguis viene riconosciuto specie valida e separata da P. flavofemoratus, concordemente con le descrizioni originali di Dejean (1828). P. flavofemoratus è distribuito a destra del solco vallivo della Dora Baltea, dal Canavese alla Val Grande di Lanzo (Alpi Graie), mentre P. pinguis è presente a sinistra del solco, nel distretto Monte Rosa/Biellese fino alla Val Formazza (Alpi Pennine e Lepontine occidentali).

Climate change and cryosphere in high mountains: updates from the Capanna Margherita hut study case (Punta Gnifetti, Monte Rosa Massif, Pennine Alps)

&lt;p&gt;Mountain glaciers and permafrost are among the most evident geomorphological tracers of climate change. In the last decades, they showed a growing and faster response also at very high elevations, leading to increased instability of the Alpine landscape. In the meanwhile, they became of great interest also for their possible interactions with human activities and infrastuctures.&lt;/p&gt;&lt;p&gt;On the highest massif of the Alps, as for example the Monte Rosa, this interaction is mainly represent by the one with mountaineering activities. The top of Gnifetti Peak (4554 m a.s.l.), with the Capanna Margherita hut (the highest in Europe), is under investigation to better understand the effects of global warming on hut stability and mountaineering routes safety. Thanks to the cooperation between the Italian Alpine Club (CAI), University of Turin (UniTo), Politecnico di Milano (PoliMi) and IMAGEO srl, a first assessment of geological and glacial settings of hut surroundings have been performed on 2019. Data collection continued on 2020, by means of comparative analyses designated to: a) identify the relevant geomechanical features for rock mass stability; b) verify permafrost related instabilities; c) reconstruct the ice-covered morphology of the Punta Gnifetti peak; d) calculate rock-building interactions. Here below the related results:&lt;/p&gt;&lt;p&gt;1) A 3D model of the area has been obtained by integrating helicopter-borne photogrammetry with terrestrial laser scanner surveys.&lt;/p&gt;&lt;p&gt;2) Glacier thickness at the Colle Gnifetti has been established thanks to GPR survey.&lt;/p&gt;&lt;p&gt;3) From the comparison of a large number of historical pictures a first multi-temporal stability analysis highlighted sector of greater instability. Results of this work are freely available on the website www.geositlab.unito.it/capanna .&lt;/p&gt;&lt;p&gt;4) The geomechanical features of the rock mass below and around the hut have been retrieved from the analysis of the dense point cloud provided by terrestrial laser scanner integrated with direct field investigations.&lt;/p&gt;&lt;p&gt;5) Constructive drawing of the hut have been obtained from the terrestrial laser scanner point cloud integrated with manual measurements taken inside the structure.&lt;/p&gt;&lt;p&gt;6) 3D numerical modelling are going to be applied in order to simulate the interactions between the hut and the foundation rock on the base of the above data.&lt;/p&gt;&lt;p&gt;The ongoing activities are addressed to a detailed study of more vulnerable sectors of the Punta Gnifetti to better understand morphodynamics and possible interactions with mountaineering activities. This will be performed through a two-way investigation. On one hand, a link with alpine guides and mountain hut keepers has been established, in order to have &amp;#8220;sentries&amp;#8221; ready to report instabilities and detect new hazards and risks. On the other hand, a monitoring network will be installed around Capanna Margherita in order to collect data on weather, glacier and permafrost conditions.&lt;/p&gt;

Deciphering the coupling between tectonic and metamorphic processes in the Monte Rosa nappe (Western Alps)

&lt;p&gt;Our refined ability to estimate metamorphic conditions incurred by rocks has increased our understanding of the dynamic earth. Calculating pressure (P), temperature (T) and time (t) histories of these rocks is vital for reconstructing tectonic movements within subduction zones. However, large disparities in peak P within a structurally coherent tectonic unit poses difficulties when attempting to resolve a tectono-metamorphic history, if a depth dependant lithostatic P is assumed. However, what is clear is that pressure, or mean stress, in a rock cannot exactly be lithostatic during an orogeny due to differential stress, required to drive rock deformation or to balance lateral variations in gravitational potential energy. Deviations from lithostatic P is commonly termed tectonic pressure, and both its magnitude and impact on metamorphic reactions in disputed.&lt;/p&gt;&lt;p&gt;For the &amp;#8216;Queen of the Alps&amp;#8217; (the Monte Rosa massif), estimates for the maximum P recorded during Alpine orogenesis remain enigmatic. Large disparities in published estimates for peak P exist, ranging between 1.2 and 2.7 GPa. Moreover, the highest P estimates (2.2 - 2.7 GPa) are for rocks that comprise only a small percentage (&lt; 1%) of the total volume of the nappe (whiteschist bodies and eclogitic mafic boudins). We present newly discovered whiteschist lithologies that persistently exhibit higher P conditions (&lt;em&gt;c.&lt;/em&gt; 2.2 GPa) compared to metagranitic and metapelitic lithologies (&lt;em&gt;c.&lt;/em&gt; 1.4 - 1.6 GPa). Detailed mapping and structural analysis in these regions lack evidence for tectonic mixing. Therefore, we suggest that a &amp;#916;P 0.6 &amp;#177; 0.2 GPa during peak Alpine metamorphism could potentially represent tectonic pressure. Furthermore, we outline possible mechanisms that facilitate &amp;#916;P, namely mechanically- and/or reaction-induced. We present data from numerical models that exhibit significant &amp;#916;P (&lt;em&gt;c.&lt;/em&gt; 0.4 GPa) during a transient period of high differential stress prior to buckling and subsequent exhumation of viscous fold nappes, similar to exhumation mechanisms suggested for the Monte Rosa nappe. As well as this, we present new routines for calculating metamorphic facies distribution within numerical models of subduction zones that agree with natural distributions within orogens.&lt;/p&gt;&lt;p&gt;The maximum burial depth of the Monte Rosa unit was likely significantly less than 80 km (based on the lithostatic pressure assumption and minor volumes of whiteschist at &lt;em&gt;c.&lt;/em&gt; 2.2 GPa). Rather, the maximum burial depth of the Monte Rosa unit was presumably equal to or less than &lt;em&gt;c.&lt;/em&gt; 60 km, estimated from pressures of 1.4 - 1.6 GPa recorded frequently in metagranite and metapelitic lithologies. In order to understanding, more completely, a rocks metamorphic history, consideration of the interplay between tectonic and metamorphic processes should not be overlooked.&lt;/p&gt;