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 ◽  
...  

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.

Geotechnics ◽  
2022 ◽  
Vol 2 (1) ◽  
pp. 14-31
Author(s):  
Brian Carlton ◽  
Andy Barwise ◽  
Amir M. Kaynia

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.


2019 ◽  
Vol 6 (1) ◽  
Author(s):  
Rashad Sawires ◽  
Miguel A. Santoyo ◽  
José A. Peláez ◽  
Raúl Daniel Corona Fernández

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.


2020 ◽  
Vol 20 (6) ◽  
pp. 1639-1661
Author(s):  
Khalid Mahmood ◽  
Naveed Ahmad ◽  
Usman Khan ◽  
Qaiser Iqbal

Abstract. Probabilistic seismic hazard analysis of Peshawar District has been performed for a grid size of 0.01∘. The seismic sources for the target location are defined as the area polygon with uniform seismicity. The earthquake catalogue was developed based on the earthquake data obtained from different worldwide seismological networks and historical records. The earthquake events obtained at different magnitude scales were converted into moment magnitude using indigenous catalogue-specific regression relationships. The homogenized catalogue was subdivided into shallow crustal and deep-subduction-zone earthquake events. The seismic source parameters were obtained using the bounded Gutenberg–Richter recurrence law. Seismic hazard maps were prepared for peak horizontal acceleration at bedrock level using different ground motion attenuation relationships. The study revealed the selection of an appropriate ground motion prediction equation is crucial for defining the seismic hazard of Peshawar District. The inclusion of deep subduction earthquakes does not add significantly to the seismic hazard for design base ground motions. The seismic hazard map developed for shallow crustal earthquakes, including also the epistemic uncertainty, was in close agreement with the map given in the Building Code of Pakistan Seismic Provisions (2007) for a return period of 475 years on bedrock. The seismic hazard maps for other return periods i.e., 50, 100, 250, 475 and 2500 years, are also presented.


2019 ◽  
Author(s):  
Khalid Mahmood ◽  
Usman Khan ◽  
Qaiser Iqbal ◽  
Naveed Ahmad

Abstract. The probabilistic seismic hazard analysis of Peshawar District has been conducted in for a grid size of 0.01. The seismic sources for the target location are defined as the area polygon with uniform seismicity for which, the earthquake catalogues were obtained from different worldwide seismological network data. The earthquake catalogues obtained in different magnitude scale was converted into moment magnitude using regression analysis. The homogenized catalogue was then further subdivided into shallow crustal and deep subduction zone earthquake events for which, the seismic source parameters were obtained using Bounded Gutenberg-Richter Recurrence law. The seismic hazard maps were prepared in term of PGA at bedrock using the different ground motion attenuation relationships. The study shows that; the selection of appropriate ground motion prediction equation is an important factor in deciding the seismic hazard of Peshawar District. The inclusion of deep subduction earthquake does not add significantly to the seismic hazard. The calculated seismic hazard map for shallow crustal earthquake after including the epistemic uncertainty was in close agreement to that developed by BCP-2007 for a return period of 475 years on bedrock. The seismic hazard maps for other return periods i.e., 50, 100, 250, 475 and 2500 years were then prepared.


2013 ◽  
Vol 479-480 ◽  
pp. 1061-1065
Author(s):  
Cheng Yu Pan ◽  
Yuan Cheih Wu ◽  
Chih Wei Chang

Tatun volcano group is located in north Taiwan and near Taipei Basin where several million people live there. Although it provides hot spring and landscape for citizens and keeps calm most of time, the threat remains, particularly for the two nearby nuclear power plants. This paper discusses the seismic hazard of volcanic seismic source including source characterization of Tatun volcano group, probabilistic seismic hazard analysis (PSHA), and its preliminary seismic hazard result. Based on nuclear regulatory requirement for PSHA, the uncertainties of source parameters are vital, such as geometry, maximum earthquake, and activity relating earthquake catalog selection, so the first-time seismic source characterization workshop for volcano is held to let domestic experts discuss their hypotheses and investigation result. Hence, the renewed source parameters can represent current geo-science for Tatun volcanic seismic source, and the process of PSHA can lead the better way to combine the result of different research projects for Tatun volcano.


2019 ◽  
Vol 5 (5) ◽  
pp. 984-995
Author(s):  
Luis Fernando Vergaray Astupina ◽  
Zenón Aguilar B. ◽  
Renzo S. Cornejo

Throughout the years seismic hazard calculations in Peru have been developed using area sources models, having to date a great variety of models, however, since they are discretized planar models, they cannot adequately represent the continuity and subduction characteristics of the Nazca Plate. The main objective of this work is the developing of a surface subduction model (SSM), useful for seismic hazard assessments as well as the revision and control of previous models used in this sort of assessments. In this study a spatial interpolation was performed employing the Local Polynomial Interpolation method to capture short-range variation in addition to long-range trends. The data base is based on the compilation of seismic catalogs from Peruvian and international institutions such as the IGP, the USGS, the ISC and others, subsequently, in order to have independent events the elimination of duplicate events, aftershocks and foreshocks was carried out. Then, by interpolation of the focal depths of the independent events, a subduction surface model (SSM) was generated as well as a Standard Error Surface which supports a good correlation of the model. Furthermore, 14 transversal sections of the SSM was employed to compare with the hypocenter’s distributions, evidencing a good correlation with the spatial distribution of the events, in addition to adequately capturing the subduction characteristics of the Nazca Plate. Finally, a comparison was made between 2 Peruvian area models for seismic hazard and SSM developed in the present research, evidencing that seismic source models of the area type have deficiencies mainly in the depths they consider, thus is recommended the use of the present model for future seismic hazard assessments.


1999 ◽  
Vol 42 (6) ◽  
Author(s):  
S. Balassanian ◽  
T. Ashirov ◽  
T. Chelidze ◽  
A. Gassanov ◽  
N. Kondorskaya ◽  
...  

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.


2015 ◽  
Vol 31 (1_suppl) ◽  
pp. S109-S130 ◽  
Author(s):  
Oliver Boyd ◽  
Kathleen Haller ◽  
Nico Luco ◽  
Morgan Moschetti ◽  
Charles Mueller ◽  
...  

The USGS National Seismic Hazard Maps were updated in 2014 and included several important changes for the central United States (CUS). Background seismicity sources were improved using a new moment-magnitude-based catalog; a new adaptive, nearest-neighbor smoothing kernel was implemented; and maximum magnitudes for background sources were updated. Areal source zones developed by the Central and Eastern United States Seismic Source Characterization for Nuclear Facilities project were simplified and adopted. The weighting scheme for ground motion models was updated, giving more weight to models with a faster attenuation with distance compared to the previous maps. Overall, hazard changes (2% probability of exceedance in 50 years, across a range of ground-motion frequencies) were smaller than 10% in most of the CUS relative to the 2008 USGS maps despite new ground motion models and their assigned logic tree weights that reduced the probabilistic ground motions by 5–20%.


2017 ◽  
Author(s):  
Hervé Jomard ◽  
Edward Marc Cushing ◽  
Luigi Palumbo ◽  
Stéphane Baize ◽  
Claire David ◽  
...  

Abstract. The French Radioprotection and Nuclear Safety Institute (IRSN), with the support of the Ministry of Environment, compiled a database (BDFA) in order to define and characterize known potentially active faults of metropolitan France. The general structure of BDFA is presented in this paper. BDFA contains to date a total of 136 faults and represent a first step toward the implementation of seismic source models that would be used for both deterministic and probabilistic hazard calculations. An example transposing BDFA into a fault source model for PSHA (Probabilistic Seismic Hazard Analysis) calculation is presented for the Upper Rhine Graben (Eastern France); and exploited in the parent paper (part B) in order to illustrate ongoing challenges for probabilistic fault-based seismic hazard calculations.


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