Evaluation of Ground‐Motion Models for USGS Seismic Hazard Forecasts: Induced and Tectonic Earthquakes in the Central and Eastern United States

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%.

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Seismic Hazard in the Eastern United States

Earthquake Spectra ◽

10.1193/110414eqs182m ◽

2015 ◽

Vol 31 (1_suppl) ◽

pp. S85-S107 ◽

Cited By ~ 12

Author(s):

Charles S. Mueller ◽

Oliver S. Boyd ◽

Mark D. Petersen ◽

Morgan P. Moschetti ◽

Sanaz Rezaeian ◽

...

Keyword(s):

United States ◽

Seismic Hazard ◽

New England ◽

Ground Motion ◽

Maximum Magnitude ◽

Eastern United States ◽

Adaptive Smoothing ◽

Motion Models ◽

Background Seismicity ◽

Ground Motion Models

The U.S. Geological Survey seismic hazard maps for the central and eastern United States were updated in 2014. We analyze results and changes for the eastern part of the region. Ratio maps are presented, along with tables of ground motions and deaggregations for selected cities. The Charleston fault model was revised, and a new fault source for Charlevoix was added. Background seismicity sources utilized an updated catalog, revised completeness and recurrence models, and a new adaptive smoothing procedure. Maximum-magnitude models and ground motion models were also updated. Broad, regional hazard reductions of 5%–20% are mostly attributed to new ground motion models with stronger near-source attenuation. The revised Charleston fault geometry redistributes local hazard, and the new Charlevoix source increases hazard in northern New England. Strong increases in mid- to high-frequency hazard at some locations—for example, southern New Hampshire, central Virginia, and eastern Tennessee—are attributed to updated catalogs and/or smoothing.

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Evaluation of Ground-Motion Models for U.S. Geological Survey Seismic Hazard Forecasts: Hawaii Tectonic Earthquakes and Volcanic Eruptions

Bulletin of the Seismological Society of America ◽

10.1785/0120180336 ◽

2020 ◽

Vol 110 (2) ◽

pp. 666-688 ◽

Cited By ~ 1

Author(s):

Daniel E. McNamara ◽

Emily Wolin ◽

Peter M. Powers ◽

Allison M. Shumway ◽

Morgan P. Moschetti ◽

...

Keyword(s):

Seismic Hazard ◽

Ground Motion ◽

Ground Motions ◽

Volcanic Eruptions ◽

Hazard Model ◽

Geological Survey ◽

Motion Models ◽

Short Period ◽

Tectonic Earthquakes ◽

Ground Motion Models

ABSTRACT The selection and weighting of ground-motion models (GMMs) introduces a significant source of uncertainty in U.S. Geological Survey (USGS) National Seismic Hazard Modeling Project (NSHMP) forecasts. In this study, we evaluate 18 candidate GMMs using instrumental ground-motion observations of horizontal peak ground acceleration (PGA) and 5%-damped pseudospectral acceleration (0.02–10 s) for tectonic earthquakes and volcanic eruptions, to inform logic-tree weights for the update of the USGS seismic hazard model for Hawaii. GMMs are evaluated using two methods. The first is a total residual visualization approach that compares the probability density function (PDF), mean and standard deviations σ, of the observed and predicted ground motion. The second GMM evaluation method we use is the common total residual probabilistic scoring method (log likelihood [LLH]). The LLH method provides a single score that can be used to weight GMMs in the Hawaii seismic hazard model logic trees. The total residual PDF approach provides additional information by preserving GMM over- and underprediction across a broad spectrum of periods that is not available from a single value LLH score. We apply these GMM evaluation methods to two different data sets: (1) a database of instrumental ground motions from historic earthquakes in Hawaii from 1973 to 2007 (Mw 4–7.3) and (2) available ground motions from recent earthquakes (Mw 4–6.9) associated with 2018 Kilauea eruptions. The 2018 Kilauea sequence contains both volcanic eruptions and tectonic earthquakes allowing for statistically significant GMM comparisons of the two event classes. The Kilauea ground observations provide an independent data set allowing us to evaluate the predictive power of GMMs implemented in the new USGS nshmp-haz software system. We evaluate GMM performance as a function of earthquake depth and we demonstrate that short-period volcanic eruption ground motions are not well predicted by any candidate GMMs. Nine of the initial 18 candidate GMMs fit the observed ground motions and meet established criteria for inclusion in the update of the Hawaii seismic hazard model. A weighted mean of four top performing GMMs in this study (NGAsubslab, NGAsubinter, ASK14, A10) is 50% lower for PGA than for GMMS used in the previous USGS seismic hazard model for Hawaii.

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Ground Motion Models Used in the 2014 U.S. National Seismic Hazard Maps

Earthquake Spectra ◽

10.1193/111714eqs194m ◽

2015 ◽

Vol 31 (1_suppl) ◽

pp. S59-S84 ◽

Cited By ~ 25

Author(s):

Sanaz Rezaeian ◽

Mark D. Petersen ◽

Morgan P. Moschetti

Keyword(s):

United States ◽

Seismic Hazard ◽

Ground Motion ◽

The United States ◽

Hazard Maps ◽

Source Characterization ◽

Ground Acceleration ◽

Seismic Hazard Maps ◽

Motion Models ◽

Ground Motion Models

The National Seismic Hazard Maps (NSHMs) are an important component of seismic design regulations in the United States. This paper compares hazard using the new suite of ground motion models (GMMs) relative to hazard using the suite of GMMs applied in the previous version of the maps. The new source characterization models are used for both cases. A previous paper ( Rezaeian et al. 2014 ) discussed the five NGA-West2 GMMs used for shallow crustal earthquakes in the Western United States (WUS), which are also summarized here. Our focus in this paper is on GMMs for earthquakes in stable continental regions in the Central and Eastern United States (CEUS), as well as subduction interface and deep intraslab earthquakes. We consider building code hazard levels for peak ground acceleration (PGA), 0.2-s, and 1.0-s spectral accelerations (SAs) on uniform firm-rock site conditions. The GMM modifications in the updated version of the maps created changes in hazard within 5% to 20% in WUS; decreases within 5% to 20% in CEUS; changes within 5% to 15% for subduction interface earthquakes; and changes involving decreases of up to 50% and increases of up to 30% for deep intraslab earthquakes for most U.S. sites. These modifications were combined with changes resulting from modifications in the source characterization models to obtain the new hazard maps.

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Implementation of NGA-West2 Ground Motion Models in the 2014 U.S. National Seismic Hazard Maps

Earthquake Spectra ◽

10.1193/062913eqs177m ◽

2014 ◽

Vol 30 (3) ◽

pp. 1319-1333 ◽

Cited By ~ 16

Author(s):

Sanaz Rezaeian ◽

Mark D. Petersen ◽

Morgan P. Moschetti ◽

Peter Powers ◽

Stephen C. Harmsen ◽

...

Keyword(s):

United States ◽

Seismic Hazard ◽

Ground Motion ◽

The United States ◽

Hazard Maps ◽

Seismic Hazard Maps ◽

Motion Models ◽

Seismic Source Models ◽

Ground Motion Models ◽

The U.S

The U.S. National Seismic Hazard Maps (NSHMs) have been an important component of seismic design regulations in the United States for the past several decades. These maps present earthquake ground shaking intensities at specified probabilities of being exceeded over a 50-year time period. The previous version of the NSHMs was developed in 2008; during 2012 and 2013, scientists at the U.S. Geological Survey have been updating the maps based on their assessment of the “best available science,” resulting in the 2014 NSHMs. The update includes modifications to the seismic source models and the ground motion models (GMMs) for sites across the conterminous United States. This paper focuses on updates in the Western United States (WUS) due to the use of new GMMs for shallow crustal earthquakes in active tectonic regions developed by the Next Generation Attenuation (NGA-West2) project. Individual GMMs, their weighted combination, and their impact on the hazard maps relative to 2008 are discussed. In general, the combined effects of lower medians and increased standard deviations in the new GMMs have caused only small changes, within 5–20%, in the probabilistic ground motions for most sites across the WUS compared to the 2008 NSHMs.

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A ground motion logic tree for seismic hazard analysis in the stable cratonic region of Europe: regionalisation, model selection and development of a scaled backbone approach

Bulletin of Earthquake Engineering ◽

10.1007/s10518-020-00940-x ◽

2020 ◽

Vol 18 (14) ◽

pp. 6119-6148

Author(s):

Graeme Weatherill ◽

Fabrice Cotton

Keyword(s):

United States ◽

Seismic Hazard ◽

Ground Motion ◽

Epistemic Uncertainty ◽

Hazard Analysis ◽

Seismic Hazard Analysis ◽

Eastern United States ◽

Logic Tree ◽

Short Period ◽

Northeastern Europe

Abstract Regions of low seismicity present a particular challenge for probabilistic seismic hazard analysis when identifying suitable ground motion models (GMMs) and quantifying their epistemic uncertainty. The 2020 European Seismic Hazard Model adopts a scaled backbone approach to characterise this uncertainty for shallow seismicity in Europe, incorporating region-to-region source and attenuation variability based on European strong motion data. This approach, however, may not be suited to stable cratonic region of northeastern Europe (encompassing Finland, Sweden and the Baltic countries), where exploration of various global geophysical datasets reveals that its crustal properties are distinctly different from the rest of Europe, and are instead more closely represented by those of the Central and Eastern United States. Building upon the suite of models developed by the recent NGA East project, we construct a new scaled backbone ground motion model and calibrate its corresponding epistemic uncertainties. The resulting logic tree is shown to provide comparable hazard outcomes to the epistemic uncertainty modelling strategy adopted for the Eastern United States, despite the different approaches taken. Comparison with previous GMM selections for northeastern Europe, however, highlights key differences in short period accelerations resulting from new assumptions regarding the characteristics of the reference rock and its influence on site amplification.

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A Suite of Alternative Ground-Motion Models (GMMs) for Israel

Bulletin of the Seismological Society of America ◽

10.1785/0120210003 ◽

2021 ◽

Author(s):

Soumya Kanti Maiti ◽

Gony Yagoda-Biran ◽

Ronnie Kamai

Keyword(s):

Seismic Hazard ◽

Ground Motion ◽

Empirical Data ◽

Epistemic Uncertainty ◽

Ground Motions ◽

Plate Boundary ◽

Strong Motion ◽

Engineering Applications ◽

Motion Models ◽

Ground Motion Models

ABSTRACT Models for estimating earthquake ground motions are a key component in seismic hazard analysis. In data-rich regions, these models are mostly empirical, relying on the ever-increasing ground-motion databases. However, in areas in which strong-motion data are scarce, other approaches for ground-motion estimates are sought, including, but not limited to, the use of simulations to replace empirical data. In Israel, despite a clear seismic hazard posed by the active plate boundary on its eastern border, the instrumental record is sparse and poor, leading to the use of global models for hazard estimation in the building code and all other engineering applications. In this study, we develop a suite of alternative ground-motion models for Israel, based on an empirical database from Israel as well as on four data-calibrated synthetic databases. Two host models are used to constrain model behavior, such that the epistemic uncertainty is captured and characterized. Despite the lack of empirical data at large magnitudes and short distances, constraints based on the host models or on the physical grounds provided by simulations ensure these models are appropriate for engineering applications. The models presented herein are cast in terms of the Fourier amplitude spectra, which is a linear, physical representation of ground motions. The models are suitable for shallow crustal earthquakes; they include an estimate of the median and the aleatory variability, and are applicable in the magnitude range of 3–8 and distance range of 1–300 km.

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Seismic hazard evaluation

Bulletin of the New Zealand Society for Earthquake Engineering ◽

10.5459/bnzsee.33.3.371-386 ◽

2000 ◽

Vol 33 (3) ◽

pp. 371-386 ◽

Cited By ~ 7

Author(s):

Paul Somerville

Keyword(s):

Seismic Hazard ◽

Ground Motion ◽

Ground Motions ◽

Strong Motion ◽

Earthquake Source ◽

Hazard Evaluation ◽

Data Set ◽

Motion Models ◽

The Past ◽

Ground Motion Models

This paper reviews concepts and trends in seismic hazard characterization that have emerged in the past decade, and identifies trends and concepts that are anticipated during the coming decade. New methods have been developed for characterizing potential earthquake sources that use geological and geodetic data in conjunction with historical seismicity data. Scaling relationships among earthquake source parameters have been developed to provide a more detailed representation of the earthquake source for ground motion prediction. Improved empirical ground motion models have been derived from a strong motion data set that has grown markedly over the past decade. However, these empirical models have a large degree of uncertainty because the magnitude - distance - soil category parameterization of these models often oversimplifies reality. This reflects the fact that other conditions that are known to have an important influence on strong ground motions, such as near- fault rupture directivity effects, crustal waveguide effects, and basin response effects, are not treated as parameters of these simple models. Numerical ground motion models based on seismological theory that include these additional effects have been developed and extensively validated against recorded ground motions, and used to estimate the ground motions of past earthquakes and predict the ground motions of future scenario earthquakes. The probabilistic approach to characterizing the ground motion that a given site will experience in the future is very compatible with current trends in earthquake engineering and the development of building codes. Performance based design requires a more comprehensive representation of ground motions than has conventionally been used. Ground motions estimates are needed at multiple annual probability levels, and may need to be specified not only by response spectra but also by suites of strong motion time histories for input into time-domain non-linear analyses of structures.

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Ranking of Ground-Motion Models (GMMs) for Use in Probabilistic Seismic Hazard Analysis for Iran Based on an Independent Data Set

Bulletin of the Seismological Society of America ◽

10.1785/0120200052 ◽

2020 ◽

Author(s):

Zoya Farajpour ◽

Milad Kowsari ◽

Shahram Pezeshk ◽

Benedikt Halldorsson

Keyword(s):

Seismic Hazard ◽

Ground Motion ◽

Selection Process ◽

Hazard Analysis ◽

Probabilistic Seismic Hazard Analysis ◽

Seismic Hazard Analysis ◽

Probabilistic Seismic Hazard ◽

Data Set ◽

Motion Models ◽

Ground Motion Models

ABSTRACT We apply three data-driven selection methods, log-likelihood (LLH), Euclidean distance-based ranking (EDR), and deviance information criterion (DIC), to objectively evaluate the predictive capability of 10 ground-motion models (GMMs) developed from Iranian and worldwide data sets against a new and independent Iranian strong-motion data set. The data set includes, for example, the 12 November 2017 Mw 7.3 Ezgaleh earthquake and the 25 November 2018 Mw 6.3 Sarpol-e Zahab earthquake and includes a total of 201 records from 29 recent events with moment magnitudes 4.5≤Mw≤7.3 with distances up to 275 km. The results of this study show that the prior sigma of the GMMs acts as the key measure used by the LLH and EDR methods in the ranking against the data set. In some cases, this leads to the resulting model bias being ignored. In contrast, the DIC method is free from such ambiguity as it uses the posterior sigma as the basis for the ranking. Thus, the DIC method offers a clear advantage of partially removing the ergodic assumption from the GMM selection process and allows a more objective representation of the expected ground motion at a specific site when the ground-motion recordings are homogeneously distributed in terms of magnitudes and distances. The ranking results thus show that the local models that were exclusively developed from Iranian strong motions perform better than GMMs from other regions for use in probabilistic seismic hazard analysis in Iran. Among the Next Generation Attenuation-West2 models, the GMMs by Boore et al. (2014) and Abrahamson et al. (2014) perform better. The GMMs proposed by Darzi et al. (2019) and Farajpour et al. (2019) fit the recorded data well at short periods (peak ground acceleration and pseudoacceleration spectra at T=0.2 s). However, at long periods, the models developed by Zafarani et al. (2018), Sedaghati and Pezeshk (2017), and Kale et al. (2015) are preferable.

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A New Procedure for Evaluating Ground-Motion Models, with Application to Hydraulic-Fracture-Induced Seismicity in the United Kingdom

Bulletin of the Seismological Society of America ◽

10.1785/0120190238 ◽

2020 ◽

Vol 110 (5) ◽

pp. 2380-2397 ◽

Cited By ~ 4

Author(s):

Gemma Cremen ◽

Maximilian J. Werner ◽

Brian Baptie

Keyword(s):

Seismic Hazard ◽

Ground Motion ◽

Shale Gas ◽

Hydraulic Fracture ◽

Induced Seismicity ◽

Ground Motions ◽

Induced Earthquakes ◽

Statistical Tool ◽

Motion Models ◽

Ground Motion Models

ABSTRACT An essential component of seismic hazard analysis is the prediction of ground shaking (and its uncertainty), using ground-motion models (GMMs). This article proposes a new method to evaluate (i.e., rank) the suitability of GMMs for modeling ground motions in a given region. The method leverages a statistical tool from sensitivity analysis to quantitatively compare predictions of a GMM with underlying observations. We demonstrate the performance of the proposed method relative to several other popular GMM ranking procedures and highlight its advantages, which include its intuitive scoring system and its ability to account for the hierarchical structure of GMMs. We use the proposed method to evaluate the applicability of several GMMs for modeling ground motions from induced earthquakes due to U.K. shale gas development. The data consist of 195 recordings at hypocentral distances (R) less than 10 km for 29 events with local magnitude (ML) greater than 0 that relate to 2018/2019 hydraulic-fracture operations at the Preston New Road shale gas site in Lancashire and 192 R<10 km recordings for 48 ML>0 events induced—within the same geologic formation—by coal mining near New Ollerton, North Nottinghamshire. We examine: (1) the Akkar, Sandikkaya, and Bommer (2014) models for European seismicity; (2) the Douglas et al. (2013) model for geothermal-induced seismicity; and (3) the Atkinson (2015) model for central and eastern North America induced seismicity. We find the Douglas et al. (2013) model to be the most suitable for almost all of the considered ground-motion intensity measures. We modify this model by recomputing its coefficients in line with the observed data, to further improve its accuracy for future analyses of the seismic hazard of interest. This study both advances the state of the art in GMM evaluation and enhances understanding of the seismic hazard related to U.K. shale gas development.

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