A Methodology for the Development of 1D Reference VS Profiles Compatible with Ground-Motion Prediction Equations: Application to NGA-West2 GMPEs

2021 ◽  
Author(s):  
Linda Al Atik ◽  
Norman Abrahamson
Keyword(s):  
Ground Motion ◽  
Site Response ◽  
Motion Prediction ◽  
Site Conditions ◽  
Ground Motion Prediction Equations ◽  
Prediction Equations ◽  
Ground Motion Prediction ◽  
Site Condition ◽  
The Impact ◽  
Over The Top

ABSTRACT Site response in ground-motion prediction equations (GMPEs) is primarily characterized as a function of the time-averaged shear-wave velocity over the top 30 m of the site profile (VS30). Although the use of VS30 as a main site-response predictor parameter is practical, GMPE site adjustments to different target regions or target site conditions require characterization of the GMPE’s rock-site response in terms of host VS profile and host kappa. Regional VS profiles and kappa values have been traditionally used to characterize GMPEs host site conditions. These regional site properties may not reflect the average site response in GMPEs. We present a methodology, based on the quarter-wavelength principles, that allows the derivation of GMPE-compatible host 1D VS profiles and kappa values. This methodology is applied to the Next Generation Attenuation-West2 (NGA-West2) GMPEs to derive GMPE-specific host VS profiles and kappa for western United States (WUS) site conditions with VS30 of 360, 490, 620, 760, and 1100 m/s. This application uses, for input, the GMPEs’ site response in Fourier amplitude spectra domain relative to a reference VS30 of 1000 m/s and requires an assigned VS profile for the reference site condition. The impact of the choice of reference VS profile on the results is not large. Comparisons of the derived GMPE-specific VS profiles for VS30 of 760 m/s show differences in the host VS profiles among the NGA-West2 GMPEs for the same site condition in WUS. Differences are also observed when comparing the derived GMPE-compatible VS profiles with the commonly used profiles for WUS for VS30 of 760 m/s. These differences highlight the importance of using GMPE-compatible VS profiles and kappa in GMPE adjustments and in site-response analyses. Limitations of this approach for soft site conditions are discussed.

scholarly journals What is the impact of the August 24, 2016 Amatrice earthquake on the seismic hazard assessment in central Italy?

2016 ◽  
Vol 59 ◽  
Author(s):  
Maura Murru ◽  
Matteo Taroni ◽  
Aybige Akinci ◽  
Giuseppe Falcone
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Hazard Assessment ◽  
Central Italy ◽  
Seismic Hazard Assessment ◽  
Motion Prediction ◽  
Ground Motion Prediction Equations ◽  
Prediction Equations ◽  
Ground Motion Prediction ◽  
The Impact

<p>The recent Amatrice strong event (M<sub>w</sub>6.0) occurred on August 24, 2016 in Central Apennines (Italy) in a seismic gap zone, motivated us to study and provide better understanding of the seismic hazard assessment in the macro area defined as “Central Italy”. The area affected by the sequence is placed between the M<sub>w</sub>6.0 1997 Colfiorito sequence to the north (Umbria-Marche region) the Campotosto area hit by the 2009 L’Aquila sequence M<sub>w</sub>6.3 (Abruzzo region) to the south. The Amatrice earthquake occurred while there was an ongoing effort to update the 2004 seismic hazard map (MPS04) for the Italian territory, requested in 2015 by the Italian Civil Protection Agency to the Center for Seismic Hazard (CPS) of the Istituto Nazionale di Geofisica e Vulcanologia INGV. Therefore, in this study we brought to our attention new earthquake source data and recently developed ground-motion prediction equations (GMPEs). Our aim was to validate whether the seismic hazard assessment in this area has changed with respect to 2004, year in which the MPS04 map was released. In order to understand the impact of the recent earthquakes on the seismic hazard assessment in central Italy we compared the annual seismic rates calculated using a smoothed seismicity approach over two different periods; the Parametric Catalog of the Historical Italian earthquakes (CPTI15) from 1871 to 2003 and the historical and instrumental catalogs from 1871 up to 31 August 2016. Results are presented also in terms of peak ground acceleration (PGA), using the recent ground-motion prediction equations (GMPEs) at Amatrice, interested by the 2016 sequence.</p>

Variation of Source-to-Site Distance for Megathrust Subduction Earthquakes: Effects on Ground Motion Prediction Equations

2014 ◽  
Vol 30 (2) ◽  
pp. 845-866 ◽  
Author(s):  
Katsuichiro Goda ◽  
Gail M. Atkinson
Keyword(s):  
Ground Motion ◽  
Motion Prediction ◽  
Fault Models ◽  
Ground Motion Prediction Equations ◽  
Prediction Equations ◽  
Ground Motion Prediction ◽  
Motion Data ◽  
Subduction Earthquakes ◽  
Finite Fault ◽  
The Impact

This study investigates the effects of using different finite-fault source models in evaluating rupture distances for megathrust subduction earthquakes. The uncertainty of the calculated rupture distances affects interpretation of the recorded ground motions significantly. To demonstrate this from an empirical perspective, ground motion data and available finite-fault models for the 2011 M9.0 Tohoku, 2003 M8.3 Tokachi-oki, and 2005 M7.2 Miyagi-oki earthquakes are analyzed. The impact of different finite-fault models on the development of ground motion prediction equations for these large subduction events is significant. Importantly, the results suggest that comparison of observed ground motion data with existing ground motion prediction models is not straightforward; different conclusions may be reached regarding agreement/disagreement between empirical data and developed models, depending on the selected finite-fault model. These results are particularly relevant to the development of ground motion prediction equations for subduction regions.

scholarly journals Next Generation Ground-Motion Prediction Equations for Indo-Gangetic Plains, India

2021 ◽  
Author(s):  
Chhotu Kumar Keshri ◽  
William Kumar Mohanty
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Hazard Analysis ◽  
Seismic Hazard Analysis ◽  
Motion Prediction ◽  
Site Conditions ◽  
Ground Motion Prediction Equations ◽  
Prediction Equations ◽  
Ground Motion Prediction ◽  
Gangetic Plains

Abstract India's Indo-Gangetic Plains (IGP) and its proximity to the Himalayas are seismically the most vulnerable zone. For seismic hazard analysis, it requires a reliable Ground Motion Prediction Equations (GMPEs) for this region. The strong motion accelerometer data are used for the present study from 2005 to 2015. PSA of 5% damped linear pseudo-absolute acceleration response spectra at 27 periods ranging from 0.01 s to 10 s used for regression. Two-stage nonlinear regression is used to train the functional form of a nonlinear magnitude scaling, distance scaling, and site conditions. The model includes a regionally independent geometric attenuation finite fault distance metric, style of faulting, shallow site response, basin response, hanging wall effect, hypocentre depth, regionally dependent anelastic attenuation, site conditions, and magnitude-dependent aleatory variability. We consider our new GMPE is valid for earthquakes from active tectonic shallow crustal continental earthquakes for estimating horizontal ground motion for rupture distances ranging from 1 km to 1500 km and magnitudes ranging from 3.3 to 7.9, and focal depth 1-70 km. The proposed GMPEs developed in this study for predicting PGA and PSA are compared with the Campbell and Bozorgnia 2008, 13 and 14, and North Indian GMPEs for IGP, which is agreed upon consistently. Calibration with observed data gives us the confidence to predict the ground motion from the seismic gaps of Himalaya ranges for the Indo-Gangetic plains. The predicted coefficients of the nonlinear model are anticipated to be valuable for probabilistic seismic hazard analysis over the IGP.

scholarly journals Ground Motion Prediction Equations for Malaysia Due to Subduction Zone Earthquakes in Sumatran Region

IEEE Access ◽  
2017 ◽  
Vol 5 ◽  
pp. 23920-23937
Author(s):  
M. S. Liew ◽  
Kamaluddeen Usman Danyaro ◽  
Mazlina Mohamad ◽  
Lim Eu Shawn ◽  
Aziz Aulov
Keyword(s):  
Subduction Zone ◽  
Ground Motion ◽  
Motion Prediction ◽  
Ground Motion Prediction Equations ◽  
Prediction Equations ◽  
Ground Motion Prediction ◽  
Subduction Zone Earthquakes

scholarly journals Ground motions in urban Los Angeles from the 2019 Ridgecrest earthquake sequence

2021 ◽  
pp. 875529302110039
Author(s):  
Filippos Filippitzis ◽  
Monica D Kohler ◽  
Thomas H Heaton ◽  
Robert W Graves ◽  
Robert W Clayton ◽  
...  
Keyword(s):  
Los Angeles ◽  
Ground Motion ◽  
Ground Motions ◽  
Earthquake Sequence ◽  
Motion Prediction ◽  
Ground Motion Prediction Equations ◽  
Prediction Equations ◽  
Ground Motion Prediction ◽  
Velocity Models ◽  
Spectral Accelerations

We study ground-motion response in urban Los Angeles during the two largest events (M7.1 and M6.4) of the 2019 Ridgecrest earthquake sequence using recordings from multiple regional seismic networks as well as a subset of 350 stations from the much denser Community Seismic Network. In the first part of our study, we examine the observed response spectral (pseudo) accelerations for a selection of periods of engineering significance (1, 3, 6, and 8 s). Significant ground-motion amplification is present and reproducible between the two events. For the longer periods, coherent spectral acceleration patterns are visible throughout the Los Angeles Basin, while for the shorter periods, the motions are less spatially coherent. However, coherence is still observable at smaller length scales due to the high spatial density of the measurements. Examining possible correlations of the computed response spectral accelerations with basement depth and Vs30, we find the correlations to be stronger for the longer periods. In the second part of the study, we test the performance of two state-of-the-art methods for estimating ground motions for the largest event of the Ridgecrest earthquake sequence, namely three-dimensional (3D) finite-difference simulations and ground motion prediction equations. For the simulations, we are interested in the performance of the two Southern California Earthquake Center 3D community velocity models (CVM-S and CVM-H). For the ground motion prediction equations, we consider four of the 2014 Next Generation Attenuation-West2 Project equations. For some cases, the methods match the observations reasonably well; however, neither approach is able to reproduce the specific locations of the maximum response spectral accelerations or match the details of the observed amplification patterns.

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