Landslides near Enguri dam (Caucasus, Georgia) and possible seismotectonic effects

The Enguri dam and water reservoir, nested in the southwestern Caucasus (Republic of Georgia), are surrounded by steep mountain slopes. At a distance of 2.5 km from the dam, a mountain ridge along the reservoir is affected by active deformations with a double vergence. The western slope, directly facing the reservoir, has deformations that affect a subaerial area of 1.2 km2. The head scarp affects the Jvari–Khaishi–Mestia main road with offsets of man-made features that indicate slip rates of 2–9 cm yr−1. Static, pseudostatic and Newmark analyses, based on field and seismological data, suggest different unstable rock volumes based on the environmental conditions. An important effect of variation of the water table is shown, as well as the possible destabilization of the slope following seismic shaking, compatible with the expected local peak ground acceleration. This worst-case scenario corresponds to an unstable volume on the order of up to 48±12×106 m3. The opposite, eastern slope of the same mountain ridge is also affected by wide deformation affecting an area of 0.37 km2. Here, field data indicate 2–5 cm yr−1 of slip rates. All this evidence is interpreted as resulting from two similar landslides, whose possible causes are discussed, comprising seismic triggering, mountain rapid uplift, river erosion and lake variations

Landsliding near Enguri dam (Caucasus, Georgia) and possible seismoectonic effects

The Enguri dam and water reservoir, nested in southwestern Caucasus (Republic of Georgia), are surrounded by steep mountain slopes. At a distance of 2.5 km from the dam, a mountain ridge along the reservoir is affected by active deformations with a double vergence. The western slope, directly facing the reservoir, has deformations that involve a subaerial area of 1.2 km2. The head scarp interests the main Jvari-Khaishi-Mestia road with offset of man-made features that indicate slip rates of 2-9 cm/y. Static, pseudostatic and Newmark numerical analyses, based on field and seismological data, suggest different unstable rock volumes basing on the environment conditions. An important effect of variation of water table is showed, as well as the possible destabilization of the landslide following seismic shaking compatible with the expected local Peak Ground Acceleration. This worst scenario corresponds to an unstable volume in the order of up to 48 ± 12*106 m3. The opposite, eastern slope of the same mountain ridge is also affected by wide deformation involving an area of 0.37 km2. Here, field data indicate 2-5 cm/y of short-term and long-term slip rates. Ground Penetrating Radar surveys of the head scarps confirm that these slip planes are steep and extend downward. All these evidences are interpreted as resulting from two similar landslides, whose possible causes are discussed, comprising seismic triggering, mountain rapid uplift, river erosion and lake variations

Évolution morpho-sédimentaire et paléo-environnementale de la plaine fluvio-deltaïque du Ticino pendant l’Holocène récent (Canton du Tessin, Suisse)

L’évolution pendant l’Holocène récent du delta du Ticino dans le Lac Majeur a été étudiée à l’aide de plusieurs sondages réalisés dans les Bolle di Magadino, de l’analyse de documents historiques et de la comparaison avec la stratigraphie pollinique déterminée dans deux petits lacs du Sud des Alpes suisses. Ces données ont permis de déterminer les principales étapes de la progradation du delta du Ticino de l’Époque romaine à aujourd’hui ainsi que l’évolution du style fluvial et de la dynamique morphosédimentaire du Ticino dans le Piano di Magadino. En particulier, grâce à une analyse des taux de sédimentation, il a été possible de mettre en évidence une intensification de l’activité hydrosédimentaire entre l’Epoque romaine et l’Antiquité tardive/Haut Moyen Âge, suivie par une période moins active pendant le Moyen Âge Central et le Bas Moyen Âge, caractérisée par un style fluvial à méandres. Le passage du Bas Moyen Âge à l’Époque Moderne a été caractérisé par l’inondation catastrophique de 1515, nommée « Buzza di Biasca », qui, en s’additionnant à l’évolution climatique naturelle, a engendré une métamorphose fluviale du Ticino, évoluant vers un style fluvial tressé qui s’est maintenu jusqu’à sa correction dans la deuxième moitié du XIXe siècle.The Late Holocene evolution of the Ticino delta in the Lake Maggiore was studied thanks to several boreholes realised in the Bolle di Magadino, to the analysis of historical documents, and to the comparison with the pollen stratigraphy determined in two small lakes of the Southern Swiss Alps. These data allowed determining the main steps of the Ticino delta progradation since the Roman Period and the evolution of the fluvial geomorphology and of the morphosedimentary dynamics of the Ticino River in the Piano di Magadino. In particular, thanks to the analysis of the sedimentation rates, it was possible to show an intensification of the hydrosedimentary activity between the Roman Period and the Late Antiquity/Early Middle Ages, followed by a less active period during the High and the Late Middle Ages, characterised by a meandering fluvial morphology. The transition between the Late Middle Ages and the Modern Epoch was characterised by the Buzza di Biasca of AD 1515. This event, which was superimposed at the natural climatic evolution, was at the origin of a fluvial metamorphosis of the Ticino River, which passes from a meandering fluvial morphology to a braided fluvial morphology. This fluvial pattern was maintained just to the Ticino canalisation of the second half of the 19th century

La miniera di rame di Campolungo : una coltivazione rivoluzionaria della prima Età del Ferro. Prime ipotesi e osservazioni: La Miniera perduta. Cinque anni di ricerche archeometallurrgische nel Territorio di Bienno

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Geosite Assessment and Communication: A Review

This work is aimed at reviewing the current state of the art in geosite selection, assessment, and communication. We first highlight the main papers that have defined paramount concepts such as geodiversity, geoheritage, and geosites. We then delve into the theoretical principles and guidelines that have been proposed over the last twenty years by researchers who have thoroughly illustrated how to individuate and assess geosites. In doing so, we illustrate notable field examples of applications of qualitative and quantitative assessments of geosites in places such as Serbia, India, Iceland, Ecuador, Sardinia (Italy), Egypt, Tasmania (Australia), and Brazil. The third part of this work is dedicated to illustrating a list (by no means exhaustive) of works that have tried to come up with innovative tools, strategies, and solutions to promote and communicate geosites. From our work, it appears that geosites can be extremely effective as fully fledged outreach tools capable of bridging the gap between Earth science and the lay public

Left Atrial Appendage: Physiology, Pathology, and Role as a Therapeutic Target

Atrial fibrillation (AF) is the most common clinically relevant cardiac arrhythmia. AF poses patients at increased risk of thromboembolism, in particular ischemic stroke. The CHADS2 and CHA2DS2-VASc scores are useful in the assessment of thromboembolic risk in nonvalvular AF and are utilized in decision-making about treatment with oral anticoagulation (OAC). However, OAC is underutilized due to poor patient compliance and contraindications, especially major bleedings. The Virchow triad synthesizes the pathogenesis of thrombogenesis in AF: endocardial dysfunction, abnormal blood stasis, and altered hemostasis. This is especially prominent in the left atrial appendage (LAA), where the low flow reaches its minimum. The LAA is the remnant of the embryonic left atrium, with a complex and variable morphology predisposing to stasis, especially during AF. In patients with nonvalvular AF, 90% of thrombi are located in the LAA. So, left atrial appendage occlusion could be an interesting and effective procedure in thromboembolism prevention in AF. After exclusion of LAA as an embolic source, the remaining risk of thromboembolism does not longer justify the use of oral anticoagulants. Various surgical and catheter-based methods have been developed to exclude the LAA. This paper reviews the physiological and pathophysiological role of the LAA and catheter-based methods of LAA exclusion

Prospects for fundamental physics with LISA

In this paper, which is of programmatic rather than quantitative nature, we aim to further delineate and sharpen the future potential of the LISA mission in the area of fundamental physics. Given the very broad range of topics that might be relevant to LISA,we present here a sample of what we view as particularly promising fundamental physics directions. We organize these directions through a “science-first” approach that allows us to classify how LISA data can inform theoretical physics in a variety of areas. For each of these theoretical physics classes, we identify the sources that are currently expected to provide the principal contribution to our knowledge, and the areas that need further development. The classification presented here should not be thought of as cast in stone, but rather as a fluid framework that is amenable to change with the flow of new insights in theoretical physics