EU Programme SAME. Draft proposal for a co-ordinated European full-scale avalanche experiment

The scope of this proposal is to describe the conclusions made in the EU programme SAME (Avalanche Mapping, Model Validation and Warning Systems) for a future co-ordinated European full-scale avalanche experiment. It is not meant to be a completed and final application for financial support in its present stage. A final application will hopefully come into being when the real participants in a potential co-ordinated experiment are singled out.EU kommisjone

Computational models for dense snow avalanche motion

Seventeen various models of dense snow avalanche motion are presented. These include statistical, comparative and energy considering models for runout distance computations as well as dynamic models for avalanche motion simulations. The latter describe either the internal dynamics of the material at certain stages of the motion, the dynamics of the moving mass as a whole from initiation to rest, or combinations of these. The dynamic models are presented with regard to the physical description of the moving material and to the mathematical and numerical modelling. Most of the dynamic models are rooted in hydraulic theory where the moving masses are described as a fluid, but also granular flow models inheriting geotechnical aspects of soil mechanics are included. Simple (quasi) three-dimensional models exist, but most of the models are still of one and two dimensions. Rather than expanding more existing models into three dimensions, the author suggests to improve the one- and two-dimensional dynamic models further, preferably by combining models based on Bagnold's (1954) concept of dispersive pressure and dynamic shear with granular flow models involving aspects of soil mechanics. Density variations, nonhomogeneous concentration, particle size distribution, cohesion, particle rotation as well as temperature changes and energy dissipation are not adequately described in any of the dynamic models. Furthermore there is a conspicuous lack of any description of stability and accuracy of the applied numerical methods. Examples of travel distance computations based on one statistical, one comparative and three dynamic models are finally presented for four Norwegian avalanches.Norges Forskningsråd (NFR

EU programme CADZIE. New concepts in avalanche hazard mapping

The main goal of the CADZIE workpackage 1 is to improve the hazard assessment process by integrating uncertainty and to develop "best-fit" models. This goal can only be achieved if both the stochastic characteristics of the avalanche system as well as the physically describable behaviour are modelled adequately. Although there exist numerous empirical and dynamical models in theory and computational form, till now only few attempts have been carried out to combine these different concepts. The objective of this report is not to develop a new constitutive law for avalanche dynamics or to derive a new statistical function for run-out estimation, but rather to integrate random processes, uncertainty, and also vague knowledge in the system description.EU CADZI

EU Programme SAME. A survey of computational models for snow avalanche motion

Various models for computation of avalanche motion are presented, both empirical procedures including statistical and comparative models for runout distance computations as well as dynamics models describing the physics of dense and powder snow avalanches, the coupled combination of these, and slush flows.EU kommisjone

The 2014 Lake Askja rockslide-induced tsunami: Optimization of numerical tsunami model using observed data

A large rockslide was released from the inner Askja caldera into Lake Askja, Iceland, on 21 July 2014. Upon entering the lake, it caused a large tsunami that traveled about ∼3 km across the lake and inundated the shore with vertical runup measuring up to 60–80 m. Following the event, comprehensive field data were collected, including GPS measurements of the inundation and multibeam echo soundings of the lake bathymetry. Using this exhaustive data set, numerical modeling of the tsunami has been conducted using both a nonlinear shallow water model and a Boussinesq-type model that includes frequency dispersion. To constrain unknown landslide parameters, a global optimization algorithm, Differential Evolution, was employed, resulting in a parameter set that minimized the deviation from measured inundation. The tsunami model of Lake Askja is the first example where we have been able to utilize field data to show that frequency dispersion is needed to explain the tsunami wave radiation pattern and that shallow water theory falls short. We were able to fit the trend in tsunami runup observations around the entire lake using the Boussinesq model. In contrast, the shallow water model gave a different runup pattern and produced pronounced offsets in certain areas. The well-documented Lake Askja tsunami thus provided a unique opportunity to explore and capture the essential physics of landslide tsunami generation and propagation through numerical modeling. Moreover, the study of the event is important because this dispersive nature is likely to occur for other subaerial impact tsunamis.Nordic Centre of Excellence on Resilience and Societal Security (NORDRESS) Research Council of Norway -231252 Icelandic Avalanche and Landslide Fund Vatnajokull National ParkPeer Reviewe

NEAMTHM18

European-Union Civil Protection Mechanism, DG-ECHO, Agreement Number: ECHO/SUB/2015/718568/PREV26Published6T. Studi di pericolosità sismica e da maremoto1SR TERREMOTI - Sorveglianza Sismica e Allerta Tsunami2SR TERREMOTI - Gestione delle emergenze sismiche e da maremoto4IT. Banche dat

The making of the NEAM Tsunami Hazard Model 2018 (NEAMTHM18)

The NEAM Tsunami Hazard Model 2018 (NEAMTHM18) is a probabilistic hazard model for tsunamis generated by earthquakes. It covers the coastlines of the North-eastern Atlantic, the Mediterranean, and connected seas (NEAM). NEAMTHM18 was designed as a three-phase project. The first two phases were dedicated to the model development and hazard calculations, following a formalized decision-making process based on a multiple-expert protocol. The third phase was dedicated to documentation and dissemination. The hazard assessment workflow was structured in Steps and Levels. There are four Steps: Step-1) probabilistic earthquake model; Step-2) tsunami generation and modeling in deep water; Step-3) shoaling and inundation; Step-4) hazard aggregation and uncertainty quantification. Each Step includes a different number of Levels. Level-0 always describes the input data; the other Levels describe the intermediate results needed to proceed from one Step to another. Alternative datasets and models were considered in the implementation. The epistemic hazard uncertainty was quantified through an ensemble modeling technique accounting for alternative models' weights and yielding a distribution of hazard curves represented by the mean and various percentiles. Hazard curves were calculated at 2,343 Points of Interest (POI) distributed at an average spacing of ∼20 km. Precalculated probability maps for five maximum inundation heights (MIH) and hazard intensity maps for five average return periods (ARP) were produced from hazard curves. In the entire NEAM Region, MIHs of several meters are rare but not impossible. Considering a 2% probability of exceedance in 50 years (ARP≈2,475 years), the POIs with MIH >5 m are fewer than 1% and are all in the Mediterranean on Libya, Egypt, Cyprus, and Greece coasts. In the North-East Atlantic, POIs with MIH >3 m are on the coasts of Mauritania and Gulf of Cadiz. Overall, 30% of the POIs have MIH >1 m. NEAMTHM18 results and documentation are available through the TSUMAPS-NEAM project website (http://www.tsumaps-neam.eu/), featuring an interactive web mapper. Although the NEAMTHM18 cannot substitute in-depth analyses at local scales, it represents the first action to start local and more detailed hazard and risk assessments and contributes to designing evacuation maps for tsunami early warning

The Making of the NEAM Tsunami Hazard Model 2018 (NEAMTHM18)

The NEAM Tsunami Hazard Model 2018 (NEAMTHM18) is a probabilistic hazard model for tsunamis generated by earthquakes. It covers the coastlines of the North-eastern Atlantic, the Mediterranean, and connected seas (NEAM). NEAMTHM18 was designed as a three-phase project. The first two phases were dedicated to the model development and hazard calculations, following a formalized decision-making process based on a multiple-expert protocol. The third phase was dedicated to documentation and dissemination. The hazard assessment workflow was structured in Steps and Levels. There are four Steps: Step-1) probabilistic earthquake model; Step-2) tsunami generation and modeling in deep water; Step-3) shoaling and inundation; Step-4) hazard aggregation and uncertainty quantification. Each Step includes a different number of Levels. Level-0 always describes the input data; the other Levels describe the intermediate results needed to proceed from one Step to another. Alternative datasets and models were considered in the implementation. The epistemic hazard uncertainty was quantified through an ensemble modeling technique accounting for alternative models’ weights and yielding a distribution of hazard curves represented by the mean and various percentiles. Hazard curves were calculated at 2,343 Points of Interest (POI) distributed at an average spacing of ∼20 km. Precalculated probability maps for five maximum inundation heights (MIH) and hazard intensity maps for five average return periods (ARP) were produced from hazard curves. In the entire NEAM Region, MIHs of several meters are rare but not impossible. Considering a 2% probability of exceedance in 50 years (ARP≈2,475 years), the POIs with MIH >5 m are fewer than 1% and are all in the Mediterranean on Libya, Egypt, Cyprus, and Greece coasts. In the North-East Atlantic, POIs with MIH >3 m are on the coasts of Mauritania and Gulf of Cadiz. Overall, 30% of the POIs have MIH >1 m. NEAMTHM18 results and documentation are available through the TSUMAPS-NEAM project website (http://www.tsumaps-neam.eu/), featuring an interactive web mapper. Although the NEAMTHM18 cannot substitute in-depth analyses at local scales, it represents the first action to start local and more detailed hazard and risk assessments and contributes to designing evacuation maps for tsunami early warning.publishedVersio

EU program CADZIE. Road traffic and avalanches - methods for risk evaluation and risk management

This report covers current methods that may be used to analyse and manage risks related to avalanches and road traffic. Avalanche types considered are primarily snow avalanches and rockslides.Cemagref EU CADZI

Verdens vakreste – og farligste? – fjord

-Spillefilmen Bølgen av Roar Uthaug er blitt en gedigen kinosuksess. Den er solgt til over 100 land og valgt som Norges Oscar-bidrag 2016. Handlingen tar utgangspunkt i et tenkt scenario, der et stort skred fra fjellet Åkerneset forårsaker en kjempemessig flodbølge i Storfjorden, Møre og Romsdal. Flodbølgen, eller tsunamien, skyller inn over Geiranger og andre lokalsamfunn – med katastrofale konsekvenser