A Far-Field Ground-Motion Model for the North Australian Craton from Plate-Margin Earthquakes

Author(s):  
Trevor I. Allen

ABSTRACT The Australian territory is just over 400 km from an active convergent plate margin with the collision of the Sunda–Banda Arc with the Precambrian and Palaeozoic Australian continental crust. Seismic energy from earthquakes in the northern Australian plate-margin region are channeled efficiently through the low-attenuation North Australian craton (NAC), with moderate-sized (Mw≥5.0) earthquakes in the Banda Sea commonly felt in northern Australia. A far-field ground-motion model (GMM) has been developed for use in seismic hazard studies for sites located within the NAC. The model is applicable for hypocentral distances of approximately 500–1500 km and magnitudes up to Mw 8.0. The GMM provides coefficients for peak ground acceleration, peak ground velocity, and 5%-damped pseudospectral acceleration at 20 oscillator periods from 0.1 to 10 s. A strong hypocentral depth dependence is observed in empirical data, with earthquakes occurring at depths of 100–200 km demonstrating larger amplitudes for short-period ground motions than events with shallower hypocenters. The depth dependence of ground motion diminishes with longer spectral periods, suggesting that the relatively larger ground motions for deeper earthquake hypocenters may be due to more compact ruptures producing higher stress drops at depth. Compared with the mean Next Generation Attenuation-East GMM developed for the central and eastern United States (which is applicable for a similar distance range), the NAC GMM demonstrates significantly higher short-period ground motion for Banda Sea events, transitioning to lower relative accelerations for longer period ground motions.

Author(s):  
J. J. Hu ◽  
H. Zhang ◽  
J. B. Zhu ◽  
G. H. Liu

AbstractA moderate magnitude earthquake with Mw 5.8 occurred on June 17, 2019, in Changning County, Sichuan Province, China, causing 13 deaths, 226 injuries, and serious engineering damage. This earthquake induced heavier damage than earthquakes of similar magnitude. To explain this phenomenon in terms of ground motion characteristics, based on 58 sets of strong ground motions in this earthquake, the peak ground acceleration (PGA), peak ground velocity (PGV), acceleration response spectra (Sa), duration, and Arias intensity are analyzed. The results show that the PGA, PGV, and Sa are larger than the predicted values from some global ground motion models. The between-event residuals reveal that the source effects on the intermediate-period and long-period ground motions are stronger than those on short-period ground motions. Comparison of Arias intensity attenuation with the global models indicates that the energy of ground motions of the Changning earthquake is larger than those of earthquakes with the same magnitude.


1995 ◽  
Vol 85 (1) ◽  
pp. 17-30 ◽  
Author(s):  
Gail M. Atkinson ◽  
David M. Boore

Abstract Predictive relations are developed for ground motions from eastern North American earthquakes of 4.0 ≦ M ≦ 7.25 at distances of 10 ≦ R ≦ 500 km. The predicted parameters are response spectra at frequencies of 0.5 to 20 Hz, and peak ground acceleration and velocity. The predictions are derived from an empirically based stochastic ground-motion model. The relations differ from previous work in the improved empirical definition of input parameters and empirical validation of results. The relations are in demonstrable agreement with ground motions from earthquakes of M 4 to 5. There are insufficient data to adequately judge the relations at larger magnitudes, although they are consistent with data from the Saguenay (M 5.8) and Nahanni (M 6.8) earthquakes. The underlying model parameters are constrained by empirical data for events as large as M 6.8.


2016 ◽  
Vol 32 (2) ◽  
pp. 951-978 ◽  
Author(s):  
Yousef Bozorgnia ◽  
Kenneth W. Campbell

We present a ground motion model (GMM) for the vertical-to-horizontal (V/H) ratios of peak ground acceleration, peak ground velocity, and 5%-damped pseudo-acceleration response spectra at periods ranging from 0.01 s to 10 s. The V/H GMM includes formulations for the median V/H ratio and for the aleatory within-event, between-event, and total standard deviations. The V/H model is based on the GMMs we have developed for the vertical and “average” horizontal components of ground motion using a mathematical formation that accounts for the correlation between these two components. We validated the V/H model against the NGA-West2 empirical database. We consider our V/H model to be valid for worldwide shallow crustal earthquakes in active tectonic regions for moment magnitudes ranging from 3.3 to 8.5, depending on the style of faulting, and for fault rupture distances ranging from 0 km to 300 km. Our V/H model incorporates period-dependent effects of magnitude saturation, style of faulting, hypocentral depth, fault-rupture dip, geometric attenuation, regionally dependent anelastic attenuation and site response, hanging-wall geometry, and magnitude-dependent between-event and within-event aleatory variabilities. The V/H ratios predicted from the model show a strong dependence on spectral period and site response.


2016 ◽  
Vol 32 (2) ◽  
pp. 979-1004 ◽  
Author(s):  
Yousef Bozorgnia ◽  
Kenneth W. Campbell

We summarize the development of the NGA-West2 Bozorgnia-Campbell empirical ground motion model (GMM) for the vertical components of peak ground acceleration (PGA), peak ground velocity (PGV), and 5%-damped elastic pseudo-absolute acceleration response spectra (PSA) at vertical periods ranging from 0.01 s to 10 s. In the development of the vertical GMM, similar to our 2014 horizontal GMM, we used the extensive PEER NGA-West2 worldwide database. We consider our new vertical GMM to be valid for shallow crustal earthquakes in active tectonic regions for magnitudes ranging from 3.3 to 7.5–8.5, depending on the style of faulting, and for distances as far as 300 km from the fault.


Author(s):  
Fabio Sabetta ◽  
Antonio Pugliese ◽  
Gabriele Fiorentino ◽  
Giovanni Lanzano ◽  
Lucia Luzi

AbstractThis work presents an up-to-date model for the simulation of non-stationary ground motions, including several novelties compared to the original study of Sabetta and Pugliese (Bull Seism Soc Am 86:337–352, 1996). The selection of the input motion in the framework of earthquake engineering has become progressively more important with the growing use of nonlinear dynamic analyses. Regardless of the increasing availability of large strong motion databases, ground motion records are not always available for a given earthquake scenario and site condition, requiring the adoption of simulated time series. Among the different techniques for the generation of ground motion records, we focused on the methods based on stochastic simulations, considering the time- frequency decomposition of the seismic ground motion. We updated the non-stationary stochastic model initially developed in Sabetta and Pugliese (Bull Seism Soc Am 86:337–352, 1996) and later modified by Pousse et al. (Bull Seism Soc Am 96:2103–2117, 2006) and Laurendeau et al. (Nonstationary stochastic simulation of strong ground-motion time histories: application to the Japanese database. 15 WCEE Lisbon, 2012). The model is based on the S-transform that implicitly considers both the amplitude and frequency modulation. The four model parameters required for the simulation are: Arias intensity, significant duration, central frequency, and frequency bandwidth. They were obtained from an empirical ground motion model calibrated using the accelerometric records included in the updated Italian strong-motion database ITACA. The simulated accelerograms show a good match with the ground motion model prediction of several amplitude and frequency measures, such as Arias intensity, peak acceleration, peak velocity, Fourier spectra, and response spectra.


2020 ◽  
Vol 110 (6) ◽  
pp. 2828-2842
Author(s):  
Esra Zengin ◽  
Norman Abrahamson

ABSTRACT The velocity pulse in near-fault ground motions has been used as a key characteristic of damaging ground motions. Characterization of the velocity pulse involves three parameters: presence of the pulse, period of the pulse, and amplitude of the pulse. The basic concept behind the velocity pulse is that a large amount of seismic energy is packed into a short time, leading to larger demands on the structure. An intensity measure for near-fault ground motions, which is a direct measure of the amount of energy arriving in short time, called instantaneous power (IP (T1)), is defined as the maximum power of the bandpass-filtered velocity time series measured over a time interval of 0.5T1, in which T1 is the fundamental period of the structure. The records are bandpass filtered in the period band (0.2T1−3T1) to remove the frequencies that are not expected to excite the structure. Zengin and Abrahamson (2020) showed that the drift is better correlated with the IP (T1) than with the velocity pulse parameters for records scaled to the same spectral acceleration at T1. A conditional ground-motion model (GMM) for the IP is developed based on the 5%-damped spectral acceleration at T1, the earthquake magnitude, and the rupture distance. This conditional GMM can be used for record selection for near-fault ground motions that captures the key features of velocity pulses and can lead to a better representation of the median and variability of the maximum interstory drift. The conditional GMM can also be used in a vector hazard analysis for spectral acceleration (T1) and IP (T1) that can be used for more accurate estimation of drift hazard and seismic risk.


2019 ◽  
Vol 35 (1) ◽  
pp. 1-20 ◽  
Author(s):  
Georgios Zalachoris ◽  
Ellen M. Rathje

A ground motion model (GMM) tuned to the characteristics of the observed, and potentially induced, seismicity in Texas, Oklahoma, and Kansas is developed using a database of 4,528 ground motions recorded during 376 events of Mw > 3.0 in the region. The GMM is derived using the referenced empirical approach with an existing Central and Eastern North America model as the reference GMM and is applicable for Mw = 3.0–5.8 and hypocentral distances less than 500 km. The proposed model incorporates weaker magnitude scaling than the reference GMM for periods less than about 1.0 s, resulting in smaller predicted ground motions at larger magnitudes. The proposed model predicts larger response spectral accelerations at short hypocentral distances (≤20 km), which is likely because of the shallow hypocenters of events in Texas, Oklahoma, and Kansas. Finally, the VS30 scaling for the newly developed model predicts less amplification at VS30 < 600 m/s than the reference GMM, which is likely because of the generally thinner sediments in the study area. This finding is consistent with recent studies regarding site amplification in Central and Eastern North America.


2017 ◽  
Vol 33 (3) ◽  
pp. 837-856 ◽  
Author(s):  
Özkan Kale ◽  
Sinan Akkar

We propose a methodology that can be useful to the hazard expert in building ground-motion logic trees to capture the center and range of ground-motion amplitudes. The methodology can be used to identify a logic-tree structure and weighting scheme that prevents the dominancy of a specific ground-motion model. This strategy can be useful for regional probabilistic seismic hazard since logic-trees biased by a specific ground-motion predictive model (GMPE) may cause disparities in the seismic hazard for regions represented by large number of sites with complex seismic features. The methodology first identifies a suit of candidate ground-motion prediction equations that can cover the center, body and range of estimated ground motions. The GMPE set is then used for establishing alternative logic-trees composed of different weighting schemes to identify the one(s) that would not be biased towards a particular GMPE due to its sensitivity to the weights. The proposed methodology utilizes visual and statistical tools to assess the ground motion distributions over large areas that makes it more practical for regional hazard studies.


2013 ◽  
Vol 05 (01) ◽  
pp. 1350006 ◽  
Author(s):  
C. JACOB ◽  
K. SEPAHVAND ◽  
V. A. MATSAGAR ◽  
S. MARBURG

The stochastic response of base-isolated building considering the uncertainty in the characteristics of the earthquakes is investigated. For this purpose, a probabilistic ground motion model, for generating artificial earthquakes is developed. The model is based upon a stochastic ground motion model which has separable amplitude and spectral non-stationarities. An extensive database of recorded earthquake ground motions is created. The set of parameters required by the stochastic ground motion model to depict a particular ground motion is evaluated for all the ground motions in the database. Probability distributions are created for all the parameters. Using Monte Carlo (MC) simulations, the set of parameters required by the stochastic ground motion model to simulate ground motions is obtained from the distributions and ground motions. Further, the bilinear model of the isolator described by its characteristic strength, post-yield stiffness and yield displacement is used, and the stochastic response is determined by using an ensemble of generated earthquakes. A parametric study is conducted for the various characteristics of the isolator. This study presents an approach for stochastic seismic response analysis of base-isolated building considering the uncertainty involved in the earthquake ground motion.


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