scholarly journals Central and Eastern United States (CEUS) Seismic Source Characterization (SSC) for Nuclear Facilities Project

2012 ◽  
Author(s):  
Kevin J. Coppersmith ◽  
Lawrence A. Salomone ◽  
Chris W. Fuller ◽  
Laura L. Glaser ◽  
Kathryn L. Hanson ◽  
...  
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%.


2021 ◽  
pp. 875529302110075
Author(s):  
Robert R Youngs ◽  
Christine A Goulet ◽  
Yousef Bozorgnia ◽  
Nicolas Kuehn ◽  
Linda Al Atik ◽  
...  

As a companion article to Goulet et al., we describe implementation of the NGA-East ground motion characterization (GMC) model in probabilistic seismic hazard analysis (PSHA) for sites in the Central and Eastern United States (CEUS). We present extensions to the EPRI/DOE/NRC seismic source characterization (SSC) model for the CEUS needed for full implementation of NGA-East. Comparisons are presented to the EPRI GMC, the currently accepted model by the U.S. Nuclear Regulatory Commission for hazard assessment at nuclear facilities. Comparisons are presented both in terms of GMC model components and in the resulting seismic hazard assessments for a range of site locations in the CEUS. Illustrations of the effect of various components of the NGA-East GMC on seismic hazard results are also presented. Finally, we present recommendations for application of the NGA-East GMC in PSHA.


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.


1987 ◽  
Vol 3 (2) ◽  
pp. 227-261 ◽  
Author(s):  
P. C. Thenhaus ◽  
D. M. Perkins ◽  
S. T. Algermissen ◽  
S. L. Hanson

The regional variability in expected ground motion associated with six different characterizations of seismic source zones for probabilistic ground motion assessment is examined for the eastern United States. Three of the seismic source zone models are based on types of geologic structure: (1) regions characterized by late-Precambrian faulting; (2) middle-to-late Paleozoic thrust tectonics; and (3) early-to-middle Mesozoic extensional features. Two other seismic source zone configurations considered are based on data related to vertical crustal movements, and the final source zone model investigated is that of Algermissen and others (1982). Maintaining the same maximum magnitude among all zones and for all source zone configurations, a comparison of results indicates a factor of 3 difference among source zone models for calculated acceleration levels in eastern Massachusetts, southeastern Maine, and the Cape Fear arch of eastern North Carolina; a factor of about 2 or greater difference for most other eastern seaboard areas; and a factor of 1.5 or less for much of the Appalachian region extending from New Brunswick to the Gulf Coast. Results show that certain source zone models based exclusively on speculative geologic hypotheses result in considerably lower ground-motion hazard than otherwise implied by accepting historical seismicity as a guide to future hazard. Significantly, variation in the seismic hazard estimates at probability levels of 1 in 500 due to uncertain earthquake causal structures or processes is considerably higher in the heavily populated northeast region than in the Charleston, South Carolina, area.


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