no / Studies of Late Bronze Age exchange and communication networks in the northern Circum-Alpine region, and central Europe as a whole, have typically focused on routes across the Alps and the circulation of high-value manufactured goods from the Italian peninsula to central Europe. Some artefacts certainly support such a movement from north to south, such as amber from the north or Pfahlbauperlen from the Po Plain. However, such objects are far outweighed by the evidence for regional exchange routes in central Europe north of the Alps. Some of these routes extended as far as northern Germany and southern Scandinavia. Whether such exchange routes were direct or down-the-line is open to debate, but it is possible that specific objects known from Switzerland represent the personal possessions of migrant individuals. Over all, it is evident that Late Bronze Age lake-dwelling communities in Switzerland were significant bronze work manufacturing centres, exporting goods to varied communities and regions across central Europe, but with potentially limited exchange, transfer, and cross fertilization of styles and equipment between eastern and western Switzerland.

L' étude comparée des structures des massifs cristallins externes et celles de la couverture dauphinoise, à la jonction Mont Blanc, Aiguilles Rouges, Belledonne permet de conclure à une déformation alpine, commune pour les deux grands ensembles lithologiques, qui combine respectivement déplacements gravitaires superficiels dans les nappes de couverture avec raccourcissement, chevauchements et décrochements crustaux profonds. Ces différents processus ont abouti au développement d'un champ régional de déformation finie (trajectoires de schistosité et d'étirement + gradients régionaux de la déformation) qui apparaît comme le résultat d'étapes successives, matérialisées à l'échelle du terrain, par une superposition de déformations. L'ordre d'apparition de ces déformations est vérifié par l'étude de la déformation incrémentale. Celle-ci permet de mettre en évidence une rotation antihoraire de l'étirement principal., générale pour l'ensemble du secteur étudié. L'ensemble des résultats de cette étude a été intégré dans un modèle de déformation progressive, ductile et hétérogène, où la direction du déplacement gravitaire superficiel de la couverture et celle du raccourcissement crustal profond sont d'abord dirigées vers le NNW puis vers l'W.

There is an undisputed need to increase accuracy of snow cover estimation in regions comprised of complex terrain, especially in areas dependent on winter snow accumulation for a substantial portion of their annual water supply, such as the Western United States, Central Asia, and the Andes. Presently, the most pertinent monitoring and research needs related to alpine snow cover area (SCA) are: (1) to improve SCA monitoring by providing detailed fractional snow cover (FSC) products which perform well in temporal/spatial heterogeneous forested and/or alpine terrains; and (2) to provide accurate measurements of FSC at the watershed scale for use in snow water equivalent (SWE) estimation for regional water management. To address the above, the presented research approach is based on Landsat Fractional Snow Cover (Landsat-FSC), as a measure of the temporal/spatial distribution of alpine SCA. A fusion methodology between remotely sensed multispectral input data from Landsat TM/ETM+, terrain information, and IKONOS are utilized at their highest respective spatial resolutions. Artificial Neural Networks (ANNs) are used to capture the multi-scale information content of the input data compositions by means of the ANN training process, followed by the ANN extracting FSC from all available information in the Landsat and terrain input data compositions. The ANN Landsat-FSC algorithm is validated (RMSE ~ 0.09; mean error ~ 0.001-0.01 FSC) in watersheds characterized by diverse environmental factors such as: terrain, slope, exposition, vegetation cover, and wide-ranging snow cover conditions. ANN input data selections are evaluated to determine the nominal data information requirements for FSC estimation. Snow/non-snow multispectral and terrain input data are found to have an important and multi-faced impact on FSC estimation. Constraining the ANN to linear modeling, as opposed to allowing unconstrained function shapes, results in a weak FSC estimation performance and therefore provides evidence of non-linear bio-geophysical and remote sensing interactions and phenomena in complex mountain terrains. The research results are presented for rugged areas located in the San Juan Mountains of Colorado, and the hilly regions of Black Hills of Wyoming, USA.

This diploma deals with history and progress of skialpinism in the (historically) Czech lands. The diploma consists of 4 parts. The first one defines the term Skialpinism in its progress stages. The second part of the diploma deals with the beginning and progress of skis as an equipment, progress of ski bindings, and other necessary equipment for skialpinism, for example climbing skins. In the third part the history of skialpinism is divided into individual stages, starting with the period 1900 {--} 1918, and then the period between the Wars, followed by the period from 1945 to 1975, and the last one is the period from 1975 to present. The fourth part covers comparison of the skialpinism evolution in the Czech lands, progress of the Czech skialpinism outside the Czech country, and the progress of skialpinism in the world.

La Corse Alpine offre une section complète du prisme orogénique alpin où la plupart des équivalents des unités décrites dans les Alpes Occidentales peuvent être trouvés sur une section de 40 km. Les minéraux d'haute pression sont exceptionnellement bien préservés, particulièrement la lawsonite, offrant un accès unique à la compréhension de zones de subduction. La Corse alpine est formée par une pile complexe d’unités métamorphiques d'origine continentale et océanique. Ces unités ont été interprétées soit comme des mélanges tectoniques complexes formés pendant la subduction alpine, soit comme les parties plus continues de lithosphère continentale et-ou océanique. Les rares estimations de condition PT sur des larges régions de la chaîne résultent en plusieurs incertitudes dans l'identification des limites séparant les unités qui ont subi des évolutions tectono-métamorphiques différentes et, par conséquent, dans la définition d'une architecture complète de la chaîne. Les données de terrain, structurelles et métamorphiques obtenues dans cette étude aux différentes échelles suggèrent que la chaîne de la Corse alpine est caractérisée par une forte conservation de structures pré-alpin, de la micro-échelle à l'échelle de la chaîne, malgré la déformation intense associée avec le métamorphisme, qui a localement donné les conditions du facies éclogitique et lawsonite. En détail, seulement neuf domaines tectono-métamorphiques homogènes ont été identifiés. Ces terrains peuvent être attribué aux domaines paléogéographiques différents qui ont subi des évolutions tectono-métamorphiques différentes. Malgré ça, les données géochronologiques fournies pendant cette étude indiquent que la Corse alpine résulte d'une évolution complexe, étant caractérisée par la signature claire tant de la tectonique alpine Eocène, à 35 Ma, que de la tectonique apennine, à 25 Ma. Les résultats fournis dans cette thèse contribuent non seulement à la compréhension des processus de subduction et de formation de montagnes, mais donnent aussi des contraintes importantes pour déchiffrer les systèmes Tethys-Alpes et Alpes-Apennine. / Alpine Corsica offers a complete section through the Alpine orogenic wedge where most equivalent of the units described in the Western Alps may be found over a 40 km section. High-pressure mineral assemblages are exceptionally well preserved, especially lawsonite, offering a unique access to the understanding of deeply subducted terranes.Alpine Corsica consists of a complex stack of variably metamorphosed units of continental and Tethys-derived material. These units have been interpreted either as complex tectonic mixing formed during the Alpine subduction, or as more continuous portions of continental and/or oceanic lithosphere. The lack of detailed PT estimates over wide regions of the belt results in several uncertainties in identifying the boundaries separating units that experienced different tectono-metamorphic evolutions and, consequently, in the definition of an exhaustive architecture of the belt.Field, structural and metamorphic data collected in this study at different scales suggest that the Alpine Corsica belt is characterized by a high preservation of pre-Alpine sctructures, from the micro-scale up the scale of the belt, despite the intense deformation essociated with metamorphism, which locally reached lawsonite-eclogite metamorphism. In particular, only nine homogeneous tectono-metamorphic domains have been identified. These terranes can be referred to different paleogeographic domains that experienced different tectono-metamorphic evolutions.Despite that, geochronological data provided during this study indicate that Alpine Corsica results fro a complex polyphase evolution, being characterized by clear signature of both Alpine tectonics, at around 35 Ma, and Apennine tectonics, at around 25 Ma.Results provided in this paper contribute not only to the understanding of processes of subduction and mountain building, but also give important constraints for deciphering the Tethys-Alps and Alps-Apennine systems.

De par leurs magnitudes élevées et leur potentiel tsunamigénique, les séismes qui se produisent en contexte de subduction présentent un risque majeur pour les villes côtières souvent densément peuplées. La compréhension de la géométrie et du fonctionnement des zones de failles associées à ces ruptures sismiques a donc fait l'objet de nombreuses recherches sismologiques et géologiques.L’objectif de cette thèse est centré sur la caractérisation des zones de failles paléo-sismiques traversant des formations ophiolitiques subductées puis exhumées en surface des continent et sur leur comparaison avec les zones sismogéniques actuelles. Elle s’appuie sur une approche multi-échelle faisant intervenir les outils de la géologie structurale, de la pétrographie microstructurale, de la minéralogie, de la géochimie ainsi que les données de la géophysique. Le cas de la Corse alpine, de par la présence de nombreuses pseudotachylytes (étant considérées comme des fossiles de séismes) mafiques et ultramafiques constitue un cas d’étude idéal.La rupture sismique dans la nappe du Cima di Gratera est matérialisée par des réseaux de pseudotachylytes parallèles ou à fort pendages situées de part et d’autre de la discontinuité tectonique séparant les unités ultramafiques et mafiques formant la nappe. Le système de faille est caractérisé par une cinématique vers l’ouest associée à la subduction de la plaque océanique liguro-piémontaise sous la plaque adriatique. Les analyses minéralogiques des microlites présentes dans les pseudotachylytes mafiques indiquent une formation des veines en contexte de pression et température du facies eclogite, correspondant à une profondeur comprise entre 60 et 70 km, soit le début de la zone de sismicité dite de profondeur intermédiaire. La géométrie du système de faille a également pu être comparée à des géométries observées via la géophysique au large du nord-est Japon et à des profondeurs similaires.A également été mis en lumière l’impact de la serpentinisation sur le caractère sismique / asismique des discontinuités tectoniques faisant intervenir des formations mafiques et ultramafiques. En effet, la fusion frictionnelle issue des ruptures sismiques et responsable de la formation des veines de pseudotachylytes n’a été observée que dans le cas où était mis en contact la péridotite fraiche ou faiblement serpentinisée et le métagabbro. Les contacts impliquant la serpentinite et le métagabbro n’en présentent jamais et peuvent donc être considérés comme asismiques. Au regard de l’épaisseur des réseaux de pseudotachylytes dans les masses de péridotite et de leur absence dans les serpentinites, les masses de péridotites peuvent donc être assimilées à des aspérités au sein même de la plaque plongeante. / By their high magnitude and their ability to generate tsunami, subduction earthquakes present a major risk for the high population density coastal cities. The understanding of the geometry and the functioning of these seismogenic fault zones was the subject of numerous seismogenic and geologic studies.The objective of this thesis is focus on the characterization of paleo-seismic fault zones cross-cutting subducted ophiolitic formation and exhumed on the continent surface, and their comparison with current seismogenic zones. This study is based on a multi-scale approach and involves structural geology, microstructural petrography, mineralogy, geochemistry and geophysics tools. The Alpine Corsica, by the presence of numerous mafic and ultramafic pseudotachylytes (considered as fossils of past earthquakes) can be considered as an ideal study case.The seismic rupture in the Cima di Gratera Nappe is materialized by pseudotachylyte networks parallel or with a steep dipping to the fault separating the mafic and ultramafic units. The fault system is characterized by a top-to-the-west kinematic associated to the Piemonte-Liguria oceanic plate subduction under the Adriatic plate. The mineralogical analyses of the mafic pseudotachylyte microlites indicate a formation under a pressure and temperature conditions of the eclogite metamorphic facies. These conditions are consistent with a depth between 60 and 70 km which correspond to the upper part of the intermediate-depth seismicity zone. The geometry of the fault system was also compared to some geometry observed by the geophysics in the NE Japan subduction zone and at similar depth.It was also highlighted the role of the serpentinization on the seismic / aseismic character of the fault involving the mafic and ultramafic formations. Indeed, frictional melting resulting from the seismic rupture responsible to the pseudotachylyte veins formation was only observed in the case where the fresh peridotite or weakly serpentinized peridotite is in contact with the metagabbro. By opposition, the deformed zones involving the serpentinite and the metagabbro never show any pseudotachylyte and can be considered as aseismic. Considering the thickness and the polyphaser character of the pseudotachylyte networks and their absence in the serpentinite, the peridotite masses can be considered as asperities within the plate itself.

Les patrons de diversité caractérisent la structure de la diversité des communautés, c'est-à-dire sa valeur, sa distribution et son changement dans l'espace et le temps. Leur étude peut amener des informations importantes sur les processus écologiques qui en sont à l'origine. Cependant de nombreuses hypothèses de travail sont faites lors de leur analyse. L'idée générale de cette thèse est qu'en remettant en cause ces hypothèses, un certain nombre de développements liés aux indices de diversité et aux modèles nuls deviennent possibles et permettent de mieux comprendre les processus écologiques à l'origine des patrons de diversité fonctionnelle ou phylogénétique. Le premier chapitre est consacré à l'étude des patrons de diversité fonctionnelle des communautés végétales alpines à de multiples échelles spatiales et organisationnelles. Le second chapitre s'intéresse aux perspectives méthodologiques amenés par les nombres de Hill. Dans le dernier chapitre, on s'intéresse aux enjeux méthodologiques d'un nouveau type de données de communautés : l'ADN environnemental. / Patterns of community diversity refers to the structure of diversity, i.e. its quantification, its distribution and its turnover in space and time. Its study is likely to shed the light on the assembly rules that determined the structure of communities. However, numerous ecological assumptions are often made when studying diversity patterns. What motivated the work was the perspective that by relaxing these assumptions, a number of developments linked to diversity indices and null models are possible and can help to understand the impact of multiple ecological processes on phylogenetic and functional diversity patterns. In a first part we studied the pattern of functional diversity of alpine plant communities as a function of spatial and organizational scales. In the second part, we studied the methodological perspectives brought by the Hill numbers. In a third part, we addressed the main methodological issues of a new type of community data: environmental DNA.

The objective of this study is to assess the uncultured bacterial diversity in the snowpack of the Mont Blanc (MtBl) glacier containing Saharan dust deposited during four dust events during the period 2006 – 2009 by means of molecular phylogenetics. The final goal is to discover the bacteria that could be involved in the establishment of snow microbiota. Bacterial diversity was evaluated using rybotyping and subsequent sequencing of partial (V3-V5) and full-length 16S rRNA genes. For comparison purpose we also studied following samples: “clean” MtBl snow containing no Saharan dust; Saharan sand collected in Tunisia; Saharan dust collected in Grenoble (200 m a.s.l.) and recovered later on MtBl (4250 m a.s.l.). In order to verify possible microbial activity in situ, both rDNA and rRNA approaches were implemented for the “clean” snow sample. To evaluate the survival/colonization abilities of bacterial phylotypes recovered in snow samples with Saharan dust, we analyzed their closest strain physiology as well as sources of environmental clones using a threshold of ≥98% sequence similarity. For the result interpretation, we also used data on dust elemental composition and dust particles size distribution. As a result 8 clone libraries (including rRNA-based one) were constructed using V3-V5 16S rRNA gene sequences for 5 snow samples (4 with Saharan dust and one “clean”), sample of Saharan dust collected in Grenoble and Saharan sand sample. Furthermore, 4 clone libraries were generated using full-length 16S rRNA gene amplicons obtained from 4 of the above snow samples (three with Saharan dust and one ‘clean'). Species content and dominant phylotypes and their assigning to major divisions varied significantly in alpine snow on a Mont Blanc glacier associated with four depositions of Saharan dust over a 3-year. Dominant phylotypes revealed are belonged to Actinobacteria, Proteobactreia, Firmicutes, Deinococcus-Thermus, Bacteroidetes and Cyanobacteria. Such variability was detected by both partial and full-length 16S rRNA gene sequencing and seems to be caused more by conditions of dust transport than bacterial load from the original dust source. Also the preservation period of dust in snowpack could affect the species composition. Thirteen icy phylotypes as candidates into snow microbiota establishing were recognized in snow containing Saharan dust and only two in “clean” snow sample. Of them, both dominant and minor phylotypes of Cyanobacteria, Proteobacteria, Actinobacteria и Firmicutes were revealed. Data on the closest strain physiology of recognized icy phylotypes suggests that representatives of genera Massilia (Betaproteobacteria), Tumebacillus (Firmicutes), Phormidium and Stigonema (both Cyanobacteria) are most relevant findings in terms of propagation in snow. By analyzing 16S rRNA from the “clean” snow containing no Saharan dust and comparing the data with those obtained for 16S rDNA library, it has been shown that Stigonema-like cyanobacterium identified could be propagating in snow at subzero temperature. Among all identified phylotypes, 10% were categorized as HA-phylotypes based on their con-specificity (≥98% similarity) with normal (non-pathogenic) human microbiome representatives. Furthermore, 11% out of all phylotypes showed less than 90% similarity with known taxa, thus, presenting novel taxa. Sequencing of both partial (V3-V5) and full-length 16S rRNA genes permitted to describe microbial diversity more fully and get more detailed picture. / The objective of this study is to assess the uncultured bacterial diversity in the snowpack of the Mont Blanc (MtBl) glacier containing Saharan dust deposited during four dust events during the period 2006 – 2009 by means of molecular phylogenetics. The final goal is to discover the bacteria that could be involved in the establishment of snow microbiota. Bacterial diversity was evaluated using rybotyping and subsequent sequencing of partial (V3-V5) and full-length 16S rRNA genes. For comparison purpose we also studied following samples: “clean” MtBl snow containing no Saharan dust; Saharan sand collected in Tunisia; Saharan dust collected in Grenoble (200 m a.s.l.) and recovered later on MtBl (4250 m a.s.l.). In order to verify possible microbial activity in situ, both rDNA and rRNA approaches were implemented for the “clean” snow sample. To evaluate the survival/colonization abilities of bacterial phylotypes recovered in snow samples with Saharan dust, we analyzed their closest strain physiology as well as sources of environmental clones using a threshold of ≥98% sequence similarity. For the result interpretation, we also used data on dust elemental composition and dust particles size distribution. As a result 8 clone libraries (including rRNA-based one) were constructed using V3-V5 16S rRNA gene sequences for 5 snow samples (4 with Saharan dust and one “clean”), sample of Saharan dust collected in Grenoble and Saharan sand sample. Furthermore, 4 clone libraries were generated using full-length 16S rRNA gene amplicons obtained from 4 of the above snow samples (three with Saharan dust and one ‘clean'). Species content and dominant phylotypes and their assigning to major divisions varied significantly in alpine snow on a Mont Blanc glacier associated with four depositions of Saharan dust over a 3-year. Dominant phylotypes revealed are belonged to Actinobacteria, Proteobactreia, Firmicutes, Deinococcus-Thermus, Bacteroidetes and Cyanobacteria. Such variability was detected by both partial and full-length 16S rRNA gene sequencing and seems to be caused more by conditions of dust transport than bacterial load from the original dust source. Also the preservation period of dust in snowpack could affect the species composition. Thirteen icy phylotypes as candidates into snow microbiota establishing were recognized in snow containing Saharan dust and only two in “clean” snow sample. Of them, both dominant and minor phylotypes of Cyanobacteria, Proteobacteria, Actinobacteria и Firmicutes were revealed. Data on the closest strain physiology of recognized icy phylotypes suggests that representatives of genera Massilia (Betaproteobacteria), Tumebacillus (Firmicutes), Phormidium and Stigonema (both Cyanobacteria) are most relevant findings in terms of propagation in snow. By analyzing 16S rRNA from the “clean” snow containing no Saharan dust and comparing the data with those obtained for 16S rDNA library, it has been shown that Stigonema-like cyanobacterium identified could be propagating in snow at subzero temperature. Among all identified phylotypes, 10% were categorized as HA-phylotypes based on their con-specificity (≥98% similarity) with normal (non-pathogenic) human microbiome representatives. Furthermore, 11% out of all phylotypes showed less than 90% similarity with known taxa, thus, presenting novel taxa. Sequencing of both partial (V3-V5) and full-length 16S rRNA genes permitted to describe

La dispersion des animaux est un processus clé pour le maintien des populations et métapopulations. En particulier, les amphibiens se déplacent beaucoup durant leur cycle de vie fait de migrations saisonnières. Ceci les rend sensibles à la structure du paysage. En effet, les modifications anthropiques comme l’aménagement d’infrastructures linéaires peuvent constituer des barrières écologiques pour les animaux et limiter le flux de gènes dans le paysage. Si les effets des routes et des lignes chemins de fer sur les déplacements des animaux ont été largement étudiés, les effets des infrastructures liées aux activités de sport d’hiver comme les pistes de ski et les remontées mécaniques sont moins bien connus. Ainsi, la perméabilité des milieux de montagne anthropisés est peu connue. Cette thèse vise à quantifier la perméabilité écologique (ou connectivité fonctionnelle), des domaines skiables pour un amphibien de montagne largement répandu : la Grenouille rousse (Rana temporaria Linnaeus 1758). Pour ce faire, nous combinons un suivi individuel de déplacements et une étude de génétique du paysage pour mieux comprendre les facteurs influençant les déplacements de grenouilles et les flux de gènes dans le paysage. Le suivi individuel est réalisé au moyen de balises GPS et d’analyses de sélection de pas (step selection analysis). L’étude de génétique du paysage est réalisée en prélevant des échantillons d’ADN dans trois domaines skiables de Savoie ainsi que dans une zone témoin située dans le Parc national de la Vanoise. Nous avons testé l’influence de plusieurs variables paysagères liées à la topographie (pente, altitude…), les habitats (réseau de zones humides, couverture du sol…) ou les activités humaines (présence de routes, de pistes de ski) sur le flux de gènes. En utilisant une nouvelle méthode d’optimisation de surface de résistance, nous montrons l’importance du réseau de zones humides pour les amphibiens de montagne. D’une part, elles servent d’habitat préférentiel et d’autre part, un réseau dense de zones humides permet d’assurer une bonne connectivité des paysages pour la Grenouille rousse. Nous mettons également en évidence que l’hétérogénéité des tailles efficaces de populations dans un paysage peut fausser les distances génétiques mesurées entre populations et nous recommandons l’utilisation de techniques pour s’affranchir de tels problèmes. Nos travaux sont importants dans une perspective de gestion durable des domaines skiables, l’aménagement de pistes de ski ou autres infrastructures de loisir pouvant être accompagnée de destructions de zones humides. / Animal disperal is a key process for maintaining populations and metapopulations. In particular, amphibians move a lot during their life cycle made of seasonal migrations. This makes them sensitive to the structure of the landscape. Indeed, anthropogenic changes such as linear infrastructure can act as ecological barriers for animals and limit gene flow within the landscape. While the effects of roads and railways on animal movements have been widely studied, the effects of infrastructure related to winter sports activities such as ski slopes and lifts are less well known. Thus, the permeability of anthropized mountain environments is little known. This thesis aims to quantify the ecological permeability (or functional connectivity) of ski areas for a widely distributed mountain amphibian: the European common frog (Rana temporaria Linnaeus 1758). To do this, we combine individual movement tracking and landscape genetics studies to better understand the factors influencing frog movements and gene flow within the landscape. Individual tracking is carried out by means of GPS tags and step selection analysis. The landscape genetics study is carried out by gathering DNA samples from three ski areas in Savoie and a control area located in the Vanoise National Park. We tested the influence of several landscape variables related to topography (slope, altitude...), habitats (wetland network, land cover...) or human activities (presence of roads, ski slopes) on gene flow. By using a new method of resistance surface optimization, we show the importance of the wetland network for mountain amphibians. On the one hand, they serve as preferential habitat and, on the other hand, a dense network of wetlands ensures good landscape connectivity for the Common frog. We also highlight that the heterogeneity in effective population sizes in a landscape can distort the genetic distances measured between populations and we recommend the use of techniques to overcome such problems. Our work is important for the sustainable management of ski areas, the development of ski slopes or other recreational infrastructure that can be accompanied by the destruction of wetlands.

The Wanganui-Wilberg landslide lies between Hokitika and Franz Josef townships, at the entrance of Harihari, on the true left bank of the Wanganui River, by State Highway 6. This apparently co-seismic landslide belongs to the class of events called rock avalanches - powerful destructive agents (Keefer, 1984) in the landscape. Other rock avalanches are numerous (Whitehouse, 1983), and widespread over the Southern Alps of New Zealand, and many appear to be co-seismic. De Mets et al. (1994) used the model NUVEL-1A to characterize the motion of the Alpine fault: 37 mm/year at an azimuth of 071° for the strike-slip and a dip-slip of 10 mm/year normal to the strike direction. Although linear when seen from the sky, the detailed morphology of the fault is more complex, called en échelon (Norris and Cooper, 1997). It exhibits metamorphosed schists (mylonite series) in its hanging wall (McCahon, 2007; Korup, 2004). Earthquakes on the Alpine fault have a recurrence time of c. 200-300 years and a probability of occurrence within 100 years of 88% (Rhoades and Van Dissen, 2002). Thought to have been triggered by the AD1220 event (determined by dendrochronology), the Wanganui-Wilberg rock avalanche deposit represents only 20% of its original volume, which was c. 33 million cubic metres. The deposit probably dammed the Wanganui River and, as a result, created a small and short-lived lake upstream. The next earthquake capable of triggering such events is likely to occur fairly soon (Yetton, 1998). Knowledge of historic catastrophic events such as the Wanganui-Wilberg rock avalanche is of crucial importance in the development of future hazard and management plans.