A Probabilistic Tsunami Hazard Study of the Auckland Region, Part II: Inundation Modelling and Hazard Assessment

2012 ◽  
Vol 170 (9-10) ◽  
pp. 1635-1646 ◽  
Author(s):  
E. M. Lane ◽  
P. A. Gillibrand ◽  
X. Wang ◽  
W. Power
2020 ◽  
Vol 8 ◽  
Author(s):  
Steven J. Gibbons ◽  
Stefano Lorito ◽  
Jorge Macías ◽  
Finn Løvholt ◽  
Jacopo Selva ◽  
...  

Probabilistic Tsunami Hazard Analysis (PTHA) quantifies the probability of exceeding a specified inundation intensity at a given location within a given time interval. PTHA provides scientific guidance for tsunami risk analysis and risk management, including coastal planning and early warning. Explicit computation of site-specific PTHA, with an adequate discretization of source scenarios combined with high-resolution numerical inundation modelling, has been out of reach with existing models and computing capabilities, with tens to hundreds of thousands of moderately intensive numerical simulations being required for exhaustive uncertainty quantification. In recent years, more efficient GPU-based High-Performance Computing (HPC) facilities, together with efficient GPU-optimized shallow water type models for simulating tsunami inundation, have now made local long-term hazard assessment feasible. A workflow has been developed with three main stages: 1) Site-specific source selection and discretization, 2) Efficient numerical inundation simulation for each scenario using the GPU-based Tsunami-HySEA numerical tsunami propagation and inundation model using a system of nested topo-bathymetric grids, and 3) Hazard aggregation. We apply this site-specific PTHA workflow here to Catania, Sicily, for tsunamigenic earthquake sources in the Mediterranean. We illustrate the workflows of the PTHA as implemented for High-Performance Computing applications, including preliminary simulations carried out on intermediate scale GPU clusters. We show how the local hazard analysis conducted here produces a more fine-grained assessment than is possible with a regional assessment. However, the new local PTHA indicates somewhat lower probabilities of exceedance for higher maximum inundation heights than the available regional PTHA. The local hazard analysis takes into account small-scale tsunami inundation features and non-linearity which the regional-scale assessment does not incorporate. However, the deterministic inundation simulations neglect some uncertainties stemming from the simplified source treatment and tsunami modelling that are embedded in the regional stochastic approach to inundation height estimation. Further research is needed to quantify the uncertainty associated with numerical inundation modelling and to properly propagate it onto the hazard results, to fully exploit the potential of site-specific hazard assessment based on massive simulations.


2015 ◽  
Vol 15 (11) ◽  
pp. 2557-2568 ◽  
Author(s):  
M. Wronna ◽  
R. Omira ◽  
M. A. Baptista

Abstract. In this paper, we present a deterministic approach to tsunami hazard assessment for the city and harbour of Sines, Portugal, one of the test sites of project ASTARTE (Assessment, STrategy And Risk Reduction for Tsunamis in Europe). Sines has one of the most important deep-water ports, which has oil-bearing, petrochemical, liquid-bulk, coal, and container terminals. The port and its industrial infrastructures face the ocean southwest towards the main seismogenic sources. This work considers two different seismic zones: the Southwest Iberian Margin and the Gloria Fault. Within these two regions, we selected a total of six scenarios to assess the tsunami impact at the test site. The tsunami simulations are computed using NSWING, a Non-linear Shallow Water model wIth Nested Grids. In this study, the static effect of tides is analysed for three different tidal stages: MLLW (mean lower low water), MSL (mean sea level), and MHHW (mean higher high water). For each scenario, the tsunami hazard is described by maximum values of wave height, flow depth, drawback, maximum inundation area and run-up. Synthetic waveforms are computed at virtual tide gauges at specific locations outside and inside the harbour. The final results describe the impact at the Sines test site considering the single scenarios at mean sea level, the aggregate scenario, and the influence of the tide on the aggregate scenario. The results confirm the composite source of Horseshoe and Marques de Pombal faults as the worst-case scenario, with wave heights of over 10 m, which reach the coast approximately 22 min after the rupture. It dominates the aggregate scenario by about 60 % of the impact area at the test site, considering maximum wave height and maximum flow depth. The HSMPF scenario inundates a total area of 3.5 km2.


2016 ◽  
Vol 173 (12) ◽  
pp. 3671-3692 ◽  
Author(s):  
Randall J. LeVeque ◽  
Knut Waagan ◽  
Frank I. González ◽  
Donsub Rim ◽  
Guang Lin

Author(s):  
Вячеслав Константинович Гусяков ◽  
Владимир Андреевич Кихтенко ◽  
Леонид Борисович Чубаров ◽  
Юрий Иванович Шокин

В работе идет речь о реализации методики вероятностного цунамирайонирования побережья, известной под названием PTHA (Probabilistic Tsunami Hazard Assessment), для создания обзорных карт цунамиопасности дальневосточного побережья России. Обсуждаются методологические основы такого подхода, проблемы построения сейсмотектонических моделей основных цунамигенных зон, численные методики получения расчетных каталогов высот волн на побережье. Приведены примеры обзорных карт для различных повторяемостей, построенных с применением методики PTHA и представленных с помощью созданного веб-приложения WTMap. Упоминаются также некоторые проблемы применения методики PTHA, связанные как с недостаточностью данных наблюдений, так и со сложностью выполнения большого объема сценарного численного моделирования. The article describes the results of the implementation of the PTHA (Probabilistic Tsunami Hazard Assessment) methodology for creating the overview maps of tsunami hazard for the Far East coast of the Russian Federation. Such maps show the characteristics of the catastrophic impact of tsunami waves on the coast and the probability of their exceeding in a given period of time. The methodological basis of the PTHA approach to the assessment of tsunami hazard, the problems of constructing seismotectonic models of the main tsunamigenic zones, mathematical models and algorithms for calculating probability estimates of tsunami danger are discussed. The version of the PTHA methodology outlined in the article is implemented as a “WTmap” Web-application that has an access to the entire observational information related to coastal tsunami zoning and software packages used. The application allows to obtain the estimates of the expected tsunami heights and their recurrence estimates and to map them on specific parts of the Far Eastern coast of the Russian Federation. The obtained estimates can be quickly recalculated when replacing the observational catalogs with more complete and reliable ones, with the addition of new, previously absent events or the revision of their parameters, as well as the results of new scenario calculations. Examples of overview maps for various recurrence intervals, constructed using the PTHA methodology and presented using the “WTMap” application, are given. Some problems of using the PTHA methodology related to the lack of available observational data and to the complexity of performing a large amount of scenario simulations are also discussed.


2014 ◽  
Vol 14 (11) ◽  
pp. 3105-3122 ◽  
Author(s):  
N. Horspool ◽  
I. Pranantyo ◽  
J. Griffin ◽  
H. Latief ◽  
D. H. Natawidjaja ◽  
...  

Abstract. Probabilistic hazard assessments are a fundamental tool for assessing the threats posed by hazards to communities and are important for underpinning evidence-based decision-making regarding risk mitigation activities. Indonesia has been the focus of intense tsunami risk mitigation efforts following the 2004 Indian Ocean tsunami, but this has been largely concentrated on the Sunda Arc with little attention to other tsunami prone areas of the country such as eastern Indonesia. We present the first nationally consistent probabilistic tsunami hazard assessment (PTHA) for Indonesia. This assessment produces time-independent forecasts of tsunami hazards at the coast using data from tsunami generated by local, regional and distant earthquake sources. The methodology is based on the established monte carlo approach to probabilistic seismic hazard assessment (PSHA) and has been adapted to tsunami. We account for sources of epistemic and aleatory uncertainty in the analysis through the use of logic trees and sampling probability density functions. For short return periods (100 years) the highest tsunami hazard is the west coast of Sumatra, south coast of Java and the north coast of Papua. For longer return periods (500–2500 years), the tsunami hazard is highest along the Sunda Arc, reflecting the larger maximum magnitudes. The annual probability of experiencing a tsunami with a height of > 0.5 m at the coast is greater than 10% for Sumatra, Java, the Sunda islands (Bali, Lombok, Flores, Sumba) and north Papua. The annual probability of experiencing a tsunami with a height of > 3.0 m, which would cause significant inundation and fatalities, is 1–10% in Sumatra, Java, Bali, Lombok and north Papua, and 0.1–1% for north Sulawesi, Seram and Flores. The results of this national-scale hazard assessment provide evidence for disaster managers to prioritise regions for risk mitigation activities and/or more detailed hazard or risk assessment.


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