A Capacity Spectrum Method for Seismic Risk Assessment

Although earthquakes and the associated damage occur in a fundamentally deterministic way, the processes are so complex that our prediction scenarios are basically uncertain approximations. In the first attempts to model hazard and risk, point estimates based on empirical data were used, however, for quite some time the more advanced seismic hazard modelling has been based on models in which the variability/uncertainty of the input parameters are consistently carried through the computations so that the results are probabilistically combined to give a median value and confidence levels that reflect on the input parameter uncertainty. For seismic damage scenarios the first tools to model uncertainties are now developing. Aware of the importance of a proper seismic risk estimation, the International Centre for Geohazards, through NORSAR and the University of Alicante (Spain), has developed a Matlab based tool in order to compute the seismic risk in urban areas using the capacity spectrum method. The user will supply built area or number of buildings in the different model building types, earthquake sources, attenuation relationships, soil maps and corresponding ground motion amplification factors, capacity curves and fragility curves corresponding to each of the model building types and finally cost models for repair or replacement. This tool will compute the probability of damage in each one of the four damage states (Slight, Moderate, Extensive and Complete) for given building types. This probability is subsequently used with the built area or number of buildings to express the results in terms of damaged area (square meters) or number of damaged buildings. Finally, using a simplified economic model, the damaged is converted to economic losses (in the input currency). The algorithm is transparent in writing and loading the input files and getting the final results. The main innovation of this tool is the implementation of the computation under a logic tree scheme, allowing epistemic uncertainties related with the different input parameters to be properly included, and the final results are provided with corresponding confidence levels. The method has been successfully applied to the city of Oslo (Molina and Lindholm, 2005). In this work we will show the main processes of the computation and an example to the seismic risk estimation. Finally, the main future development will be focused in the implementation of first order reliability methods (FORM) which recently have been proved as useful to capture also the aleatory uncertainty

A Next-Generation Open-Source Tool for Earthquake Loss Estimation

Earthquake loss estimation (ELE), generally also referred to as earthquake risk assessment, is a comparably young research discipline which, at first, relied on empirical observations based on a macroseismic intensity scale. Later, with the advent of methodologies and procedures that are based on theoretical simulation in estimating physical damage under earthquake loading, the analytical approach for ELE was formulated. The open-source software SELENA, which is a joint development of NORSAR (Norway) and the University of Alicante (Spain), is undergoing a constant development. One of the more recent features being included is the possibility to address topographic amplification of seismic ground motion. Additionally, SELENA has been adapted by including various methods for the analytical computation of structural damage and loss. SELENA now offers complete flexibility in the use of different types of fragility curves based on various ground motion intensity parameters (e.g. PGA, Sa, Sd), which has been suggested by many recently released guidelines (e.g. FEMA P-58, GEM-ASV, SYNER-G, HAZUS- MH). Besides, under the framework of the ongoing Horizon 2020 LIQUEFACT project, SELENA is extended in order to allow the consideration of liquefaction-induced ground displacements and respective structural damage. In general, software tools for ELE are particularly useful in two different settings, i.e., for disaster management and (re)insurance purposes. Both sectors pose very different demands on ELE studies: while the (re)insurance sector is foremost interested in the direct and indirect economic losses caused by an earthquake to its insured physical assets, those institutions (often governmental and non- governmental organizations) in charge of disaster emergency management and response are more interested in reliable estimates on human losses and the potential short- and long-term social consequences. Being aware about these peculiar differences between software tools for disaster management and insurance applications, NORSAR/UA thereby offers two in its core similar software tools, i.e., the open-source software SELENA and the proprietary software PML (Probable Maximum Loss) which is actively used by the insurance association in Chile (South America) since 2011.The present research has been benefited from funding of NORSAR and the Univ. Alicante through research contracts (NORSAR1-14A, NORSAR1-08I), the funding of the Ministerio de Economía, Industria y Competitividad (CGL2016-77688-R) and the Generalitat Valenciana (BEST/2012/173 and AICO/2016/098). The development and implementation of the liquefaction risk assessment methodology is done under the LIQUEFACT project funded by the European Union’s Horizon 2020 research and innovation programme under grant agreement (No. 700748)

The European Plate Observing System and the Arctic

The European Plate Observing System (EPOS) aims to integrate existing infrastructures in the solid earth sciences into a single infrastructure, enabling earth scientists across Europe to combine, model, and interpret multidisciplinary datasets at different time and length scales. In particular, a primary objective is to integrate existing research infrastructures within the fields of seismology, geodesy, geophysics, geology, rock physics, and volcanology at a pan-European level. The added value of such integration is not visible through individual analyses of data from each research infrastructure; it needs to be understood in a long-term perspective that includes the time when changes implied by current scientific research results are fully realized and their societal impacts have become clear. EPOS is now entering its implementation phase following a four-year preparatory phase during which 18 member countries in Europe contributed more than 250 research infrastructures to the building of this pan-European vision. The Arctic covers a significant portion of the European plate and therefore plays an important part in research on the solid earth in Europe. However, the work environment in the Arctic is challenging. First, most of the European Plate boundary in the Arctic is offshore, and hence, sub-sea networks must be built for solid earth observation. Second, ice covers the Arctic Ocean where the European Plate boundary crosses through the Gakkel Ridge, so innovative technologies are needed to monitor solid earth deformation. Therefore, research collaboration with other disciplines such as physical oceanography, marine acoustics, and geo-biology is necessary. The establishment of efficient research infrastructures suitable for these challenging conditions is essential both to reduce costs and to stimulate multidisciplinary research.Le système European Plate Observing System (EPOS) vise l’intégration des infrastructures actuelles en sciences de la croûte terrestre afin de ne former qu’une seule infrastructure pour que les spécialistes des sciences de la Terre des quatre coins de l’Europe puissent combiner, modéliser et interpréter des ensembles de données multidisciplinaires moyennant diverses échelles de temps et de longueur. Un des principaux objectifs consiste plus particulièrement à intégrer les infrastructures de recherche existantes se rapportant aux domaines de la sismologie, de la géodésie, de la géophysique, de la géologie, de la physique des roches et de la volcanologie à l’échelle paneuropéenne. La valeur ajoutée de cette intégration n’est pas visible au moyen des analyses individuelles des données émanant de chaque infrastructure de recherche. Elle doit plutôt être considérée à la lumière d’une perspective à long terme, lorsque les changements qu’impliquent les résultats de recherche scientifique actuels auront été entièrement réalisés et que les incidences sur la société seront claires. Le système EPOS est en train d’amorcer sa phase de mise en oeuvre. Cette phase succède à la phase préparatoire de quatre ans pendant laquelle 18 pays membres de l’Europe ont soumis plus de 250 infrastructures de recherche en vue de l’édification de cette vision paneuropéenne. L’Arctique couvre une grande partie de la plaque européenne et par conséquent, il joue un rôle important dans les travaux de recherche portant sur la croûte terrestre en Europe. Cependant, le milieu de travail de l’Arctique n’est pas sans défis. Premièrement, la majorité de la limite de la plaque européenne se trouvant dans l’Arctique est située au large, ce qui signifie que des réseaux marins doivent être aménagés pour permettre l’observation de la croûte terrestre. Deuxièmement, de la glace recouvre l’océan Arctique, là où la limite de la plaque européenne traverse la dorsale de Gakkel, ce qui signifie qu’il faut recourir à des technologies innovatrices pour surveiller la déformation de la croûte terrestre. C’est pourquoi les travaux de recherche doivent nécessairement se faire en collaboration avec d’autres disciplines comme l’océanographie physique, l’acoustique marine et la géobiologie. L’établissement d’infrastructures de recherche efficaces capables de faire face à ces conditions rigoureuses s’avère essentiel, tant pour réduire les coûts que pour stimuler la recherche multidisciplinaire

Yoga jam: remixing Kirtan in the Art of Living

Yoga Jam are a group of musicians in the United Kingdom who are active members of the Art of Living, a transnational Hindu-derived meditation group. Yoga Jam organize events—also referred to as yoga raves and yoga remixes—that combine Hindu devotional songs (bhajans) and chants (mantras) with modern Western popular musical genres, such as soul, rock, and particularly electronic dance music. This hybrid music is often played in a clublike setting, and dancing is interspersed with yoga and meditation. Yoga jams are creative fusions of what at first sight seem to be two incompatible phenomena—modern electronic dance music culture and ancient yogic traditions. However, yoga jams make sense if the Durkheimian distinction between the sacred and the profane is challenged, and if tradition and modernity are not understood as existing in a sort of inverse relationship. This paper argues that yoga raves are authenticated through the somatic experience of the modern popular cultural phenomenon of clubbing combined with therapeutic yoga practices and validated by identifying this experience with a reimagined Vedic tradition

Hazus application to Oslo municipality: data description

In order to apply HAZUS methodology to a real seismic risk study outside USA, the Oslo municipality was chosen as study region. The civil institutions were asked for neccesary information and we were provided with different ASCII and Arcview files which I will describe here.NORSAR; Universidad de Alicant

Hazusicg v1.0 : user and technical manual

A Matlab-based seismic risk tool has been developed and named HAZUSICG. Obviously this tool is still in development but it can provided damage results for the general building stock of a city or country and also for the essential facilities as schools, hospitals, emergency response facilities, etc. if they have provided as input file (censuscenter.txt where the latitude and the longitude correspond to the location of the facility). The code has been written so it runs easily with some inputs from the user using the keyboard. Uncertainties are included by running the code several times and changing input parameters, so different output files are obtained which are multiplied by their corresponding probabilities (weights of the branches of the logic tree) and treated with the statistical tools of Matlab to get the median and standard deviation. The input files are so transparent that they can be easily adjusted to any part of the world, just only taking into consideration the possibility of new model building types with other capacity and fragility curves. That’s an advantage with respect to HAZUS which has lower flexibility in terms of non-USA areas and building types. The m-scripts which form HAZUSICG are commented so user can go through the lines and easily change them if necessary.NORSAR; Universidad de Alicant

Riskicg v2.4: user and technical manual

A Matlab-based seismic risk tool has been developed and named RISKICG. This tool is still in development, but it can provide damage results and economic losses for the general building stock of a city or country and also for the essential facilities as schools, hospitals, emergency response facilities, etc. if they are provided as input information in the files. This can be done by introducing a new census tract and a new building type (if required) corresponding to the location and structure of the facility. This will involve changes in the files builtarea.txt and soilcenter?.txt and others. The code has been written so that the user can introduce most of the needed inputs in a windows environment. The input files are so transparent that they can be easily adjusted to any part of the world, only taking into consideration the possibility of new model building types with other capacity and fragility curves. The m-scripts which form RISKICG are commented so that the user can go through the lines and easily change them if necessary.NORSAR; Universidad de Alicant

Earthquake related tsunami hazard along the western coast of Thailand

The primary background for the present study was a project to assist the authorities in Thailand with development of plans for how to deal with the future tsunami risk in both short and long term perspectives, in the wake of the devastating 26 December 2004 Sumatra-Andaman earthquake and tsunami. The study is focussed on defining and analyzing a number of possible future earthquake scenarios (magnitudes 8.5, 8.0 and 7.5) with associated return periods, each one accompanied by specific tsunami modelling. Along the most affected part of the western coast of Thailand, the 2004 tsunami wave caused a maximum water level ranging from 5 to 15 m above mean sea level. These levels and their spatial distributions have been confirmed by detailed numerical simulations. The applied earthquake source is developed based on available seismological and geodetic inversions, and the simulation using the source as initial condition agree well with sea level records and run-up observations. A conclusion from the study is that another megathrust earthquake generating a tsunami affecting the coastline of western Thailand is not likely to occur again for several hundred years. This is in part based on the assumption that the Southern Andaman Microplate Boundary near the Simeulue Islands constitutes a geologic barrier that will prohibit significant rupture across it, and in part on the decreasing subduction rates north of the Banda Ache region. It is also concluded that the largest credible earthquake to be prepared for along the part of the Sunda-Andaman arc that could affect Thailand, is within the next 50–100 years an earthquake of magnitude 8.5, which is expected to occur with more spatial and temporal irregularity than the megathrust events. Numerical simulations have shown such earthquakes to cause tsunamis with maximum water levels up to 1.5–2.0 m along the western coast of Thailand, possibly 2.5–3.0 m on a high tide. However, in a longer time perspective (say more than 50–100 years) the potentials for earthquakes of similar magnitude and consequences as the 2004 event will become gradually larger and eventually posing an unacceptable societal risk. These conclusions apply only to Thailand, since the effects of an M 8.5 earthquake in the same region could be worse for north-western Sumatra, the Andaman and Nicobar Islands, maybe even for Sri Lanka and parts of the Indian coastline. Moreover, further south along the Sunda arc the potentials for large ruptures are now much higher than for the region that ruptured on 26 December 2004