This study presents an open and transparent exposure model for the residential building stock in South America. This model captures the geographical distribution, structural characteristics (including information about construction materials, lateral load resisting system, range of number of stories), average built-up area, replacement cost, expected number of occupants, and number of dwellings and buildings. The methodology utilized to develop this model was based on national population and housing statistics and expert judgment from dozens of local researchers and practitioners. This model has been developed as part of the South America Risk Assessment (SARA) project led by the Global Earthquake Model (GEM), and it can be used to perform earthquake risk analyses. It is available at different geographical scales for seven Andean countries: Argentina, Bolivia, Chile, Colombia, Ecuador, Peru, and Venezuela.

This study presents an open-source framework for the evaluation of the consequences of seismic events on transportation systems, and their impact on the surrounding industry. When applied to the specific case of a given company or organization, the framework allows the estimation of expected losses due to the disruption of specific transportation routes. The methodology was applied to a case study of a Portuguese mining factory whose production and exportation rely on the accessibility to strategic regions in the country using the highway and railway networks. Several methodological issues (e.g., spatial correlation in the ground motion, correlation in the damage) are explored within a sensitivity analysis to identify which features can impact seismic performance indicators (collapse and disruption probabilities; repair and disruption time) of specific routes.

The evaluation of earthquake damage considering past events can be a useful tool to verify or calibrate damage and risk models, as well as to assess the possible consequences that future events may cause in a region. This study describes a process to estimate earthquake damage considering past events, and using the OpenQuake-engine, the open-source software for seismic hazard and risk analysis of the Global Earthquake Model Foundation. Exposure and fragility models from the recently completed South America Risk Assessment (SARA) project were combined with conditioned ground motion fields from past events to calculate structural damage in the affected region. These results can facilitate the creation of risk reduction measures, such as retrofitting campaigns, development of insurance mechanisms and enhancement of building codes. The challenges in assessing damage and losses from past events are thoroughly discussed, and several recommendations are proposed.

This study presents a seismic vulnerability and risk assessment of the residential building stock in Costa Rica. It proposes a new exposure model using housing census data, public construction statistics, and private construction information to quantify and characterize the residential building portfolio. A complete vulnerability catalogue is established by developing fragility functions for the most common building classes and combining them with existing models derived for risk assessment in South America. An existing probabilistic seismic hazard model was implemented within the OpenQuake-engine, and complemented with a simplified site model to account for site effects. Earthquake risk assessment is achieved by means of a probabilistic event-based analysis, which allowed the estimation of several risk metrics. These include average annualized losses at a national scale, disaggregated per building class and administrative regions. The probable maximum losses and exceedance probability curves were generated using a stochastic event set with 100,000 years of events per logic tree branch.

ThisisthefinalreportproducedinthecontextoftheGEMStrainRateProject,oneoftheglobalcomponents of the GEM Foundation. The project was charged to analyse and synthesize all available geodetic data in order tocreateaglobaldatasetofgeodeticvelocities thatcanbeused tomodelplatemotionsandstrain ratesinplateboundaryzones.To thisend,weestimated6533velocities fromposition time-series thatwe derived fromtheanalysisofRINEXdatathatwaseither freelyavailableormadeavailabletousspecifically forthisproject.Allbut 15ofthesevelocitieswereusedinthemodelling.Inaseparateanalysis,wealsoreanalysed all RINEX data in China and effectively added 1143 velocities to the data set. Finally, we added 13,318velocitiesfrom216studiesinthepublishedliterature(orfrompersonalcommunications)toachievea grandtotalof20,979velocitiesat17,491uniquelocationsusedinthemodelling.Ofallvelocities, 16,325are inplateboundaryzones(asdefinedbyus)andtheremaining4654velocitiesareforpointson,predefined, rigidtectonicplatesorblocks.Wecreatedaglobalmeshthathas144,827deformingcellsof0.2°(latitudinal) by 0.25° (longitudinal) dimension covering the plate boundary zones,with the remaining cells covering 50 rigidplatesandblocks.For36oftheseplates,weestimatedtherigid-bodyrotation fromourdataset,and the rotations of the remaining plates are taken from the literature. The rigid-body rotations are used as boundaryconditionsinthestrainratecalculations.ThestrainratefieldismodelledusingtheHainesandHolt method,whichusessplinestoobtainaninterpolatedvelocitygradienttensorfield,fromwhichstrainrates, vorticityrates,andexpectedvelocitiesarederived.Wealsoestimatedmodeluncertainties,specificforthis high-resolution mesh, which indicates that there still are many areas with large strain rate uncertainties where the data spacing is often much larger than the cell dimensions. Nevertheless, the model and data input are a tremendous improvement to the previous global strain rate model from 2004. All results are transferred to GEM and are also archived and displayed by a dedicated server hosted by UNAVCO (gsrm2.unavco.org), one of the project's partners. In addition, we created a kmz-layer of contour's of the secondinvariantofthemodelstrainrates,andwecreatedanonlinetoolthatwouldallowausertoupload hisownvelocitiesandplotthemwiththevelocitiesintheGEMdatasetin53differentreferenceframes.

In one sense, all seismology is the study of historical earthquakes. Earthquakes are short-lived phenomena; over within a couple of minutes at most, well before the seismologist can arrive on the scene. Every earthquake is history, albeit recent history, by the time it can be studied. This inability to observe an earthquake in real time has coloured the development of seismology as a science. In lieu of direct observation, scientists have been obliged to rely on secondary phenomena, or to put it another way, on traces left by the earthquake. These can be grouped into three: permanent marks left on the landscape, written descriptions of the effects of an earthquake, and the recordings made by instruments specifically designed to register the movement of the ground during an earthquake. These three different types of data are the three pillars on which seismological knowledge rests.

Guidelines (GEM-ASV) for developing analytical seismic vulnerability functions are offered for use within the framework of the Global Earthquake Model (GEM). Emphasis is on low/mid-rise buildings and cases where the analyst has the skills and time to perform non-linear analyses. The target is for a structural engineer with a Master’s level training and the ability to create simplified non-linear structural models to be able to determine the vulnerability functions pertaining to structural response, damage, or loss for any single structure, or for a class of buildings defined by the GEM Taxonomy level 1 attributes. At the same time, sufficient flexibility is incorporated to allow full exploitation of cutting-edge methods by knowledgeable users. The basis for this effort consists of the key components of the state-of-art PEER/ATC-58 methodology for loss assessment, incorporating simplifications for reduced effort and extensions to accommodate a class of buildings rather than a single structure, and multiple damage states rather than collapse only considerations.

A procedure is offered forthe analytical derivation ofthe seismic vulnerability of building classes, that is, probabilistic relationships between shaking and repair cost as a fraction of replacement cost new for a categoryofbuildings.Itsimulatesstructural response,damage,and repaircost for thestructuralandnonstructuralcomponents thatcontributemost toconstructioncost,and thenscalesup results toaccount for the components thatwere not simulated.It does so fora carefully selected sample of building specimens called index buildings whose designs span the domain of up to three features that are believed to most strongly influence seismic vulnerability within the building class. One uses moment matching to combine results for theindexbuildings toestimatebehaviourandvariabilityof thebuildingclass.Onecansimulate non-structuralvulnerabilityalonebyignoringdamageandrepaircostforstructuralcomponents.Theworkis written for a structural engineer with a master’s degree, skilled in structural analysis, but not necessarily experiencedinlossmodelling.

These Guidelines provide state-of-the-art guidance on the construction of vulnerability relationships from post-earthquake survey data. The Guidelines build on and extend procedures for empirical fragility and vulnerability curve construction found in the literature, and present a flexible framework for the construction of these relationships that allows for a number of curve-fitting methods and ground motion intensity measure types (IMTs) to be adopted. The philosophy behind the design of the framework is that the characteristics of the data should determine the most appropriate statistical model and intensity measure type used to represent them. Hence, several combinations of these must be trialled in the determination of an optimum fragility or vulnerability curve, where the optimum curve is defined by the statistical model that provides the best fit to the data as determined by a number of goodness-of-fit tests. The Guidelines are essentially a roadmap for the process, providing recommendations and help in deciding which statistical model to attempt, and promote trialling of models and IMTs.

Fromtheinception oftheGEMGlobalEarthquakeConsequencesDatabase(GEMECD)theambitionwasthat the database will serve to inform users on consequences from past events, as a benchmarking tool for analyticallossmodelsand to support thedevelopmentof tools tocreatevulnerabilitydataappropriate to specificcountries,structures,orbuildingclasses.Theaimofthisreportistosummarisetheworkcarriedout by 10internationalpartners toachieve thisgoalandincludesadescriptionof thedatabasein termsofits contents and framework, the development of a set of guidelines for data collection and templates to populate thedatabaseandfinallysomeexamplesoftypesofinformationincludedinGEMECD,notablythe updatedUSGSShakemaps.