scholarly journals Bayesian validation of the seismic source models using the Wylfa Newydd site in the UK as a case study

2021 ◽  
Author(s):  
Ilaria Mosca ◽  
Brian Baptie ◽  
Manuela Villani ◽  
Z. Lubkowski ◽  
T. Courtney
Keyword(s):  
Seismic Hazard Assessment ◽  
Seismic Source ◽  
Probabilistic Seismic Hazard Assessment ◽  
Source Characterization ◽  
Statistical Tool ◽  
The United Kingdom ◽  
Nuclear Site ◽  
Seismic Source Models ◽  
Source Models ◽  
The Uk

Abstract In probabilistic seismic hazard assessment, the development of the seismic source characterization, especially the geometry of the seismic source models (SSMs), is controversial because it often relies on expert judgment with different interpretations of the available data from seismology, tectonics, and geology. Based on the same input datasets, different teams of experts may derive different SSMs. In this context, the verification of the models through the comparison against a set of observations is a crucial step. We present a statistical tool to compare the SSMs with the observed seismicity and rank these SSMs based on their ability to replicate the past seismicity. We simulate many synthetic catalogues derived from candidate SSMs and compare them with the observed catalogue of mainshocks using the Metropolis-Hastings Algorithm to select those that fit the observed catalogue. The candidate SSMs are then expressed by a probability density function (pdf) using the set of synthetic catalogues accepted by the Metropolis-Hastings Algorithm and the Bayesian inference. To help practitioners in earthquake and civil engineering understand how this tool works in practice, the proposed approach is applied to a proposed new nuclear site in the United Kingdom, Wylfa Newydd.

scholarly journals An updated and unified earthquake catalog from 1787 to 2018 for seismic hazard assessment studies in Mexico

2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Rashad Sawires ◽  
Miguel A. Santoyo ◽  
José A. Peláez ◽  
Raúl Daniel Corona Fernández
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Seismic Hazard Assessment ◽  
Large Earthquake ◽  
Seismic Source ◽  
Earthquake Catalog ◽  
Magnitude Conversion ◽  
Seismic Source Models ◽  
Source Models ◽  
Definition Of

Abstract Here we present a new updated and unified Poissonian earthquake catalog for Mexico. The details about the catalog compilation, the removal of duplicate events, unifying the magnitude scales, removal of dependent events through the declustering process and its completeness analysis are presented. Earthquake and focal mechanism data have been compiled from various local, regional and international sources. Large earthquake events (MW ≥ 6.5) have been carefully revised for their epicentral locations and magnitudes from trusted publications. Different magnitude-conversion relationships, compatible with available local and regional ones, has been established to obtain unified moment magnitude estimates for the whole catalog. Completeness periods for the declustered catalog were estimated for the definition of appropriate seismic source models for the whole territory. The final unified Poissonian earthquake catalog spans from 1787 to 2018, covering a spatial extent of 13° to 33°N and 91° to 117°W. This catalog is compatible with other published catalogs providing basis for new analysis related to seismicity, seismotectonics and seismic hazard assessment in Mexico.

scholarly journals Determination of Local Site-Specific Spectra Using Probabilistic Seismic Hazard Analysis for Bitlis Province, Turkey

2015 ◽  
Vol 19 (2) ◽  
pp. 129-134 ◽  
Author(s):  
Ercan Işık ◽  
Mustafa Kutanis
Keyword(s):  
Seismic Hazard ◽  
Hazard Analysis ◽  
Seismic Hazard Assessment ◽  
Seismic Source ◽  
Response Spectra ◽  
Probabilistic Seismic Hazard Assessment ◽  
Probabilistic Seismic Hazard ◽  
Source Characterization ◽  
Site Specific ◽  
Attenuation Relationships

<p>In this study, site-specific earthquake spectra for Bitlis province in Lake Van Basin has been obtained. It is noteworthy that, in probabilistic seismic hazard assessment, as a first stage data from geological studies and records from the instrumental period were compiled to make a seismic source characterization for the study region.The probabilistic seismic hazard curves for Bitlis were developed based on selected appropriate attenuation relationships, at rock sites, with a probability of exceedance 2%, 10% and 50% in 50 year periods. The obtained results were compared with the spectral responses proposed for seismic evaluation and retrofit of the building structure in Turkish Earthquake Code, Section 2. At the end of this study, it is apprehended that the Code proposed earthquake response spectra are not sufficient for the performance evaluation of the existing structures and the current estimations show that the potential seismic hazard research of the Turkey is underestimated in the code.Therefore, site- specific design spectra for the region should be developed, which reflect the characteristics of local sites.</p><p> </p><p><strong>Determinación de espectros de sitio específico locales a través del análisis probabilístico de amenazas sísmicaspara la provincia de Bitlis, Turquía</strong></p><p> </p><p><strong>Resumen</strong></p>En este estudio se obtuvieron espectros de terremoto de sitio específico para la cuenca del Lago de Van, en la provincia de Bitlis, al este de Turquía. La primera fase del trabajo consistió en una evaluación probabilística de riesgo sísmico donde se compilaron los estudios geológicos y registros del período instrumental para hacer una caracterización de fuente sísmica en la región de estudio. Las curvas de amenaza sísmica para la provincia de Bitlis se desarrollaron con base en las relaciones de atenuación apropiada seleccionadas en los sitios rocosos, con una probabilidad de exceso de 2 %, 10 % y 50 % durante 50 años. Los resultados obtenidos se compararon con las respuestas de espectro propuestas para la evaluación sísmica y modernización de estructuras contempladas en el Código de Terremoto de Turquía, en la sección 2. En la parte final de este trabajo se comprende que las respuestas de espectros de terremoto propuestos en el código no son suficientes para la evaluación de desempeño de las estructuras existentes y que las estimaciones actuales muestran que la investigación de amenazas potenciales sísmicas en Turquía está subestimada en el código. Por lo tanto, el diseño de espectros de sitio específico para la región se debe desarrollar, ya que permitiría conocer las singularidades locales.</p>

scholarly journals Seismic Hazard Assessment for a Wind Farm Offshore England

Geotechnics ◽  
2022 ◽  
Vol 2 (1) ◽  
pp. 14-31
Author(s):  
Brian Carlton ◽  
Andy Barwise ◽  
Amir M. Kaynia
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
North Sea ◽  
Wind Farm ◽  
Seismic Source ◽  
Offshore Wind ◽  
Source Characterization ◽  
North East ◽  
Seismic Source Models ◽  
Source Models

Offshore wind has become a major contributor to reducing global carbon emissions. This paper presents a probabilistic seismic hazard analysis for the Sofia Offshore Wind Farm, which is located about 200 km north-east of England in the southern North Sea and will be one of the largest offshore wind farms in the world once completed. The seismic source characterization is composed of two areal seismic source models and four seismic source models derived using smoothed gridded seismicity with earthquake catalogue data processed by different techniques. The ground motion characterization contains eight ground motion models selected based on comparisons with regional data. The main findings are (1) the variation in seismic hazard across the site is negligible; (2) the main source controlling the hazard is the source that includes the 1931 Dogger Bank earthquake; (3) earthquake scenarios controlling the hazard are Mw = 5.0–6.3 and R = 110–210 km; and (4) the peak ground accelerations on rock are lower than for previous regional studies. These results could help guide future seismic hazard assessments in the North Sea.

scholarly journals Planar Seismic Source Characterization Models Developed for Probabilistic Seismic Hazard Assessment of Istanbul

2017 ◽  
Author(s):  
Zeynep Gülerce ◽  
Kadir Buğra Soyman ◽  
Barış Güner ◽  
Nuretdin Kaymakci
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Seismic Hazard Assessment ◽  
Seismic Source ◽  
Probabilistic Seismic Hazard Assessment ◽  
Model Parameters ◽  
Probabilistic Seismic Hazard ◽  
Maximum Magnitude ◽  
Source Characterization ◽  
Seismicity Rates

Abstract. This contribution provides an updated planar seismic source characterization (SSC) model to be used in the probabilistic seismic hazard assessment (PSHA) for Istanbul. It defines planar rupture systems for the four main segments of North Anatolian Fault Zone (NAFZ) that are critical for the PSHA of Istanbul: segments covering the rupture zones of 1999 Kocaeli and Düzce earthquakes, Central Marmara, and Ganos/Saros segments. In each rupture system, the source geometry is defined in terms of fault length, fault width, fault plane attitude, and segmentation points. Activity rates and the magnitude recurrence models for each rupture system are established by considering geological and geodetic constraints and are tested based on the observed seismicity that associated with the rupture system. Uncertainty in the SSC model parameters (e.g. b-value, maximum magnitude, weights of the rupture scenarios) is considered in the logic tree. To acknowledge the effect of earthquakes that are not associated with the defined rupture systems on the hazard, a background zone is introduced and the seismicity rates in the background zone are calculated using smoothed-seismicity approach. The state-of-the-art SSC model presented here is the first fully-documented and ready-to-use fault-based SSC model developed for the PSHA of Istanbul.

scholarly journals Planar seismic source characterization models developed for probabilistic seismic hazard assessment of Istanbul

2017 ◽  
Vol 17 (12) ◽  
pp. 2365-2381 ◽  
Author(s):  
Zeynep Gülerce ◽  
Kadir Buğra Soyman ◽  
Barış Güner ◽  
Nuretdin Kaymakci
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Seismic Hazard Assessment ◽  
Seismic Source ◽  
Probabilistic Seismic Hazard Assessment ◽  
Model Parameters ◽  
Probabilistic Seismic Hazard ◽  
Maximum Magnitude ◽  
Source Characterization ◽  
Seismicity Rates

Abstract. This contribution provides an updated planar seismic source characterization (SSC) model to be used in the probabilistic seismic hazard assessment (PSHA) for Istanbul. It defines planar rupture systems for the four main segments of the North Anatolian fault zone (NAFZ) that are critical for the PSHA of Istanbul: segments covering the rupture zones of the 1999 Kocaeli and Düzce earthquakes, central Marmara, and Ganos/Saros segments. In each rupture system, the source geometry is defined in terms of fault length, fault width, fault plane attitude, and segmentation points. Activity rates and the magnitude recurrence models for each rupture system are established by considering geological and geodetic constraints and are tested based on the observed seismicity that is associated with the rupture system. Uncertainty in the SSC model parameters (e.g., b value, maximum magnitude, slip rate, weights of the rupture scenarios) is considered, whereas the uncertainty in the fault geometry is not included in the logic tree. To acknowledge the effect of earthquakes that are not associated with the defined rupture systems on the hazard, a background zone is introduced and the seismicity rates in the background zone are calculated using smoothed-seismicity approach. The state-of-the-art SSC model presented here is the first fully documented and ready-to-use fault-based SSC model developed for the PSHA of Istanbul.

scholarly journals Seismic hazard assessment for the Caucasus test area

1999 ◽  
Vol 42 (6) ◽  
Author(s):  
S. Balassanian ◽  
T. Ashirov ◽  
T. Chelidze ◽  
A. Gassanov ◽  
N. Kondorskaya ◽  
...  
Keyword(s):  
Seismic Hazard ◽  
Hazard Assessment ◽  
Seismic Hazard Assessment ◽  
Seismic Source ◽  
Test Area ◽  
The Caucasus ◽  
Seismicity Rate ◽  
Seismic Catalogue ◽  
Seismic Source Models ◽  
Source Models

The GSHAP CAUCAS test area was established under the INTAS Ct.94-1644 (Test Area for sismic Hazard Assessment in the Caucasus) and NATO ARW Ct.95-1521 (Historical and Prehistorical Earthquakes in the Caucasus), with the initial support of IASPEI, UNESCO and ILP. The high tectonic interest and seismicity rate of the whole area, the availability of abundant multi-disciplinary data and the long established tradition in hazard assessment provide a unique opportunity to test different methodologies in a common test area and attempt to establish some consensus in the scientific community. Starting from the same input data (historical and instrumental seismic catalogue, lineament and homogeneous seismic source models) six independent approaches to seismic hazard assessment have been used, ranging from pure historical deterministic to seismotectonic probabilistic and areal assessment methodologies. The results are here compared.

A probabilistic seismic hazard assessment for Wylfa Newydd, a new nuclear site in the United Kingdom

2020 ◽  
Vol 18 (9) ◽  
pp. 4061-4089 ◽  
Author(s):  
Manuela Villani ◽  
Zygmunt Lubkowski ◽  
Matthew Free ◽  
Roger M. W. Musson ◽  
Barbara Polidoro ◽  
...  
Keyword(s):  
United Kingdom ◽  
Seismic Hazard ◽  
Hazard Assessment ◽  
Seismic Hazard Assessment ◽  
Probabilistic Seismic Hazard Assessment ◽  
Probabilistic Seismic Hazard ◽  
The United Kingdom ◽  
Nuclear Site

scholarly journals Seismic Source Characterization for the 2014 Update of the U.S. National Seismic Hazard Model

2015 ◽  
Vol 31 (1_suppl) ◽  
pp. S31-S57 ◽  
Author(s):  
Morgan P. Moschetti ◽  
Peter M. Powers ◽  
Mark D. Petersen ◽  
Oliver S. Boyd ◽  
Rui Chen ◽  
...  
Keyword(s):  
United States ◽  
Seismic Hazard ◽  
Epistemic Uncertainty ◽  
Source Parameters ◽  
Seismic Source ◽  
Hazard Model ◽  
Source Characterization ◽  
Seismic Source Models ◽  
Source Models ◽  
Model Components

We present the updated seismic source characterization (SSC) for the 2014 update of the National Seismic Hazard Model (NSHM) for the conterminous United States. Construction of the seismic source models employs the methodology that was developed for the 1996 NSHM but includes new and updated data, data types, source models, and source parameters that reflect the current state of knowledge of earthquake occurrence and state of practice for seismic hazard analyses. We review the SSC parameterization and describe the methods used to estimate earthquake rates, magnitudes, locations, and geometries for all seismic source models, with an emphasis on new source model components. We highlight the effects that two new model components—incorporation of slip rates from combined geodetic-geologic inversions and the incorporation of adaptively smoothed seismicity models—have on probabilistic ground motions, because these sources span multiple regions of the conterminous United States and provide important additional epistemic uncertainty for the 2014 NSHM.

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