A history of tourism at the Mer de Glace: Adaptations of glacier tourism to glacier fluctuations since 1741

Climate change induces profound changes in mountain territories that affect the activities pursued there.Tourism is one activity that is strongly impacted by these changes.Most research on tourism in mountain regions has focused on winter sports tourism,but glacier tourism,a summer activity,is also severely affected by climate change-induced phenomena,including glacier retreat and other geomorphological processes.Given that Alpine glacier tourism has been pursued since the 18th century and glaciers have been changing throughout this period,this article aims to examine the adaptations implemented by glacier tourism operators since the activity’s beginnings.Through analysis of historical documents,glaciological surveys and semi-structured interviews,this paper reveals how tourism activities around the Mer de Glace(the largest French glacier)have been impacted by glacier fluctuations since the first visit to the area in 1741.The study reveals that these developments have mainly been driven by glacier retreat and associated paraglacial dynamics.More recently,the shortening of the period of snow cover on the glacier has also impacted tourism activities.Most of the adaptation strategies implemented by tourism operators during the period in question are found to be reactive,consisting in the installation of safety equipment,the renovation of access points or the building of new structures to allow tourist activities to continue despite the consequences of glacier retreat.Other strategies,such as the adoption of new activities by workers previously specialised in another,are identified that could be considered transformative strategies,although these were only adopted by workers when their activity was no longer feasible.The analysis of materials from 1741 to the present also reveals that the recent impacts of climate change on glacier tourism are much more significant and diverse than those produced by past fluctuations.Therefore,it is important that stakeholders take suitable measures to ensure the sustainable future of the Mer de Glace and other glacier tourism destinations.

The East Anatolia-Lesser Caucasus ophiolite:An exceptional case of large-scale obduction,synthesis of data and numerical modelling

We present new,geological,metamorphic,geochemical and geochronological data on the East Anatolian-Lesser Caucasus ophiolites.These data are used in combination with a synthesis of previous data and numerical modelling to unravel the tectonic emplacement of ophiolites in this region.All these data allow the reconstruction of a large obducted ophiolite nappe,thrusted for>100 km and up to 250 km on the Anatolian-Armenian block.The ophiolite petrology shows three distinct magmatic series,highlighted by new isotopic and trace element data:(1)The main Early Jurassic Tholeiites(ophiolite s.s.)bear LILEenriched,subduction-modified,MORB chemical composition.Geology and petrology of the Tholeiite series substantiates a slow-spreading oceanic environment in a time spanning from the Late Triassic to the Middle-Late Jurassic.Serpentinites,gabbros and plagiogranites were exhumed by normal faults,and covered by radiolarites,while minor volumes of pillow-lava flows infilled the rift grabens.Tendency towards a subduction-modified geochemical signature suggests emplacement in a marginal basin above a subduction zone.(2)Late Early Cretaceous alkaline lavas conformably emplaced on top of the ophiolite.They have an OIB affinity.These lavas are featured by large pillow lavas interbedded a carbonate matrix.They show evidence for a large-scale OIB plume activity,which occurred prior to ophiolite obduction.(3)Early-Late Cretaceous calc-alkaline lavas and dykes.These magmatic rocks are found on top of the obducted nappe,above the post-obduction erosion level.This series shows similar Sr-Nd isotopic features as the Alkaline series,though having a clear supra-subduction affinity.They are thus interpreted to be the remelting product of a mantle previously contaminated by the OIB plume.Correlation of data from the Lesser Caucasus to western Anatolia shows a progression from back-arc to arc and fore-arc,which highlight a dissymmetry in the obducted oceanic lithosphere from East to West.The metamorphic P-T-t paths of the obduction sole lithologies define a southward propagation of the ophiolite:(1)P-T-t data from the northern Sevan-Akera suture zone(Armenia)highlight the presence and exhumation of eclogites(1.85±0.02 GPa and 590±5℃)and blueschists below the ophiolite,which are dated at ca.94 Ma by Ar-Ar on phengite.(2)Neighbouring Amasia(Armenia)garnet amphibolites indicate metamorphic peak conditions of 0.65±0.05 GPa and 600±20 C with a U-Pb on rutile age of 90.2±5.2 Ma and Ar-Ar on amphibole and phengite ages of 90.8±3.0 Ma and 90.8±1.2 Ma,respectively.These data are consistent with palaeontological dating of sediment deposits directly under(Cenomanian,i.e.>93.9 Ma)or sealing(Coniacian-Santonian,i.e.,≤89.8 Ma),the obduction.(3)At Hinis(NE Turkey)PT-t conditions on amphibolites(0.66±0.06 GPa and 660±20℃,with a U-Pb titanite age of80.0±3.2 Ma)agree with previous P-T-t data on granulites,and highlight a rapid exhumation below a top-to-the-North detachment sealed by the Early Maastrichtian unconformity(ca.70.6 Ma).Amphibolites are cross-cut by monzonites dated by U-Pb on titanite at 78.3±3.7 Ma.We propose that the HT-MP metamorphism was coeval with the monzonites,about 10 Ma after the obduction,and was triggered by the onset of subduction South of the Anatolides and by reactivation or acceleration of the subduction below the Pontides-Eurasian margin.Numerical modelling accounts for the obduction of an"old"~80 Myr oceanic lithosphere due to a significant heating of oceanic lithosphere through mantle upwelling,which increased the oceanic lithosphere buoyancy.The long-distance transport of a currently thin section of ophiolites(<1 km)onto the Anatolian continental margin is ascribed to a combination of northward mantle extensional thinning of the obducted oceanic lithosphere by the Hinis detachment at ca.80 Ma,and southward gravitational propagation of the ophiolite nappe onto its foreland basin.

The Challenging Place of Natural Hazards in Disaster Risk Reduction Conceptual Models:Insights from Central Africa and the European Alps

Based on a literature review and two case studies,this article presents the difficulties inherent in the main disaster risk reduction conceptual models.The method used to highlight such evidence is to compare two programs on disaster risk reduction with mainstream conceptual models.The authors participated in these programs,which were confronted with the need to integrate contributions and insights from both earth and social sciences.Our analysis found that the existing main conceptual models were unable to do justice to disaster risk reduction needs.This finding encouraged us to critique these models.Further effort led us to present possible solutions to compensate for the shortcomings of current models while taking into account the contextualization and dynamics of phenomena,as well as grappling with the more explicit integration of hazards and hazard risk into model design.