NGA-West2 Equations for Predicting PGA, PGV, and 5% Damped PSA for Shallow Crustal Earthquakes

2014 ◽  
Vol 30 (3) ◽  
pp. 1057-1085 ◽  
Author(s):  
David M. Boore ◽  
Jonathan P. Stewart ◽  
Emel Seyhan ◽  
Gail M. Atkinson
Keyword(s):  
Intensity Measures ◽  
Global Database ◽  
Crustal Earthquakes ◽  
Aleatory Variability ◽  
Distance Dependence ◽  
Active Tectonic ◽  
Class 1 ◽  
Site Term ◽  
Residuals Analysis ◽  
Variability Model

We provide ground motion prediction equations for computing medians and standard deviations of average horizontal component intensity measures (IMs) for shallow crustal earthquakes in active tectonic regions. The equations were derived from a global database with M 3.0–7.9 events. We derived equations for the primary M- and distance-dependence of the IMs after fixing the V S30-based nonlinear site term from a parallel NGA-West2 study. We then evaluated additional effects using mixed effects residuals analysis, which revealed no trends with source depth over the M range of interest, indistinct Class 1 and 2 event IMs, and basin depth effects that increase and decrease long-period IMs for depths larger and smaller, respectively, than means from regional V S30-depth relations. Our aleatory variability model captures decreasing between-event variability with M, as well as within-event variability that increases or decreases with M depending on period, increases with distance, and decreases for soft sites.

Physically Parameterized Prediction Equations for Significant Duration in Active Crustal Regions

2016 ◽  
Vol 32 (4) ◽  
pp. 2057-2081 ◽  
Author(s):  
Kioumars Afshari ◽  
Jonathan P. Stewart
Keyword(s):  
Standard Deviation ◽  
Ground Motions ◽  
Prediction Equations ◽  
Global Database ◽  
Significant Duration ◽  
Crustal Earthquakes ◽  
Aleatory Variability ◽  
Active Tectonic ◽  
Variability Model ◽  
Source Duration

We develop prediction equations for the median and standard deviation of the significant duration of earthquake ground motions from shallow crustal earthquakes in active tectonic regions. We consider significant duration parameters for 5–75%, 5–95%, and 20–80% of the normalized Arias intensity. The equations were derived from a global database with M 3.0–7.9 events. We find significant noise effects on duration parameters that compel us to exclude some records that had been used previously to develop models for amplitude parameters. Our equations include an M-dependent source duration term that also depends on focal mechanism. At small M, the data suggest approximately M-independent source durations that are close to 1 sec. The increase of source durations with M is slower over the range ∼5 to 7.2–7.4 than for larger magnitudes. We adopt an additive path term with breaks in distance scaling at 10 km and 50 km. We include site terms that increase duration for decreasing V S30 and increasing basin depth. Our aleatory variability model captures decreasing between- and within-event standard deviation terms with increasing M.

NGA-West2 Equations for Predicting Vertical-Component PGA, PGV, and 5%-Damped PSA from Shallow Crustal Earthquakes

2016 ◽  
Vol 32 (2) ◽  
pp. 1005-1031 ◽  
Author(s):  
Jonathan P. Stewart ◽  
David M. Boore ◽  
Emel Seyhan ◽  
Gail M. Atkinson
Keyword(s):  
Site Response ◽  
Vertical Component ◽  
Site Amplification ◽  
Intensity Measures ◽  
Global Database ◽  
Crustal Earthquakes ◽  
Anelastic Attenuation ◽  
Nonlinear Site Response ◽  
Active Tectonic ◽  
Geometric Spreading

We present ground motion prediction equations (GMPEs) for computing natural log means and standard deviations of vertical-component intensity measures (IMs) for shallow crustal earthquakes in active tectonic regions. The equations were derived from a global database with M 3.0–7.9 events. The functions are similar to those for our horizontal GMPEs. We derive equations for the primary M- and distance-dependence of peak acceleration, peak velocity, and 5%-damped pseudo-spectral accelerations at oscillator periods between 0.01–10 s. We observe pronounced M-dependent geometric spreading and region-dependent anelastic attenuation for high-frequency IMs. We do not observe significant region-dependence in site amplification. Aleatory uncertainty is found to decrease with increasing magnitude; within-event variability is independent of distance. Compared to our horizontal-component GMPEs, attenuation rates are broadly comparable (somewhat slower geometric spreading, faster apparent anelastic attenuation), VS30-scaling is reduced, nonlinear site response is much weaker, within-event variability is comparable, and between-event variability is greater.

Update of the Chiou and Youngs NGA Model for the Average Horizontal Component of Peak Ground Motion and Response Spectra

2014 ◽  
Vol 30 (3) ◽  
pp. 1117-1153 ◽  
Author(s):  
Brian S.-J. Chiou ◽  
Robert R. Youngs
Keyword(s):  
Ground Motion ◽  
Hanging Wall ◽  
Response Spectra ◽  
Rupture Directivity ◽  
Crustal Earthquakes ◽  
Aleatory Variability ◽  
Source Distance ◽  
Active Tectonic ◽  
Peak Ground Motion ◽  
Horizontal Ground Motion

We present an update to our 2008 NGA model for predicting horizontal ground motion amplitudes caused by shallow crustal earthquakes occurring in active tectonic environments. The update is based on analysis of the greatly expanded NGA-West2 ground motion database and numerical simulations. The updated model contains minor adjustments to our 2008 functional form related to style of faulting effects, hanging wall effects, scaling with the depth to top of rupture, scaling with sediment thickness, and the inclusion of additional terms for the effects of fault dip and rupture directivity. In addition, we incorporate regional differences in far-source distance attenuation and site effects between California and other active tectonic regions. Compared to our 2008 NGA model, the predicted medians by the updated model are similar for M > 7 and are lower for M < 5. The aleatory variability is larger than that obtained in our 2008 model.

An NGA Model for the Average Horizontal Component of Peak Ground Motion and Response Spectra

2008 ◽  
Vol 24 (1) ◽  
pp. 173-215 ◽  
Author(s):  
BrianS-J. Chiou ◽  
Robert R. Youngs
Keyword(s):  
Ground Motion ◽  
Ground Motions ◽  
Hanging Wall ◽  
Response Spectra ◽  
Horizontal Component ◽  
Smooth Functions ◽  
Soil Response ◽  
New Model ◽  
Crustal Earthquakes ◽  
Aleatory Variability

We present a model for estimating horizontal ground motion amplitudes caused by shallow crustal earthquakes occurring in active tectonic environments. The model provides predictive relationships for the orientation-independent average horizontal component of ground motions. Relationships are provided for peak acceleration, peak velocity, and 5-percent damped pseudo-spectral acceleration for spectral periods of 0.01 to 10 seconds. The model represents an update of the relationships developed by Sadigh et. al. (1997) and incorporates improved magnitude and distance scaling forms as well as hanging-wall effects. Site effects are represented by smooth functions of average shear wave velocity of the upper 30 m ( VS30) and sediment depth. The new model predicts median ground motion that is similar to Sadigh et. al. (1997) at short spectral period, but lower ground motions at longer periods. The new model produces slightly lower ground motions in the distance range of 10 to 50 km and larger ground motions at larger distances. The aleatory variability in ground motion amplitude was found to depend upon earthquake magnitude and on the degree of nonlinear soil response, For large magnitude earthquakes, the aleatory variability is larger than found by Sadigh et. al. (1997).

Geomorphic Indexes of Tectonic Activity Relative through The Analysis Quantitative in Cisanggarung Watershed, Kuningan District, West Java, Indonesia

2021 ◽  
pp. 367-375
Author(s):  
Ajeng Sekarkirana Pramesti Kameswara ◽  
Nana Sulaksana ◽  
Murni Sulastri ◽  
P. P. Raditya R.
Keyword(s):  
Activity Index ◽  
Shape Index ◽  
Research Area ◽  
Tectonic Activity ◽  
West Java ◽  
High Class ◽  
Watershed Area ◽  
Average Value ◽  
Active Tectonic ◽  
Class 1

The research area is very interesting to study to determine the characterization of the active tectonic influence of the Cisanggarung watershed, West Java. The research area is in Kuningan Regency, West Java. The purpose of this study was to determine the Relative Tectonic Activity Index (Iatr) in the Cisanggarung Watershed. Through the method approach used to identify the Relative Tectonic Activity Index (Iatr) using geomorphic indexes, watershed asymmetry factors (Af), watershed shape index (Bs), valley width, and height valley ratio (Vf), and mountainous face sinusitis (Smf). The Iatr research area is divided into 4 classes: Class 1 (very high), class 2 (high), class 3 (medium), and class 4 (low). Iatr distribution in 14 sub-watersheds covering an area of 286.24 km2 is Class 1 around 14.44% of the watershed area (41.35 km2) which is located in sub-watershed 1, with Smf values 1.157, Vf 0.3, Af 72.15, and Bs 4.3. Class 2 around 28.67% of the watershed area (82.09 km2) is located in sub-watershed 14, with Smf values 1.26, Vf 0.77, Af 15.69, Bs 1.01. Class 3 around 54.16% of the watershed area (155.03 km2) is located in sub-watersheds 2, 3, 6, 7, 8, 10, 11, 12, with an average value of Smf 2, Vf 1.54, Af 51.77, Bs 1.75, and Class 4 about 2.71% of the watershed area (7.76 km2) is located in sub- watersheds 4, 5, 9, 13, with an average value of Smf 2.25, Vf 8.18, Af 55.2, Bs 1.65. The results of the morphometric analysis indicated that the study area was mostly affected by tectonics and erosion.

Comparisons of the NGA Ground-Motion Relations

2008 ◽  
Vol 24 (1) ◽  
pp. 45-66 ◽  
Author(s):  
Norman Abrahamson ◽  
Gail Atkinson ◽  
David Boore ◽  
Yousef Bozorgnia ◽  
Kenneth Campbell ◽  
...  
Keyword(s):  
Site Response ◽  
Strike Slip ◽  
Data Sets ◽  
Sediment Depth ◽  
Long Period ◽  
Crustal Earthquakes ◽  
Nonlinear Site Response ◽  
Soil Sediment ◽  
Active Tectonic ◽  
Standard Deviations

The data sets, model parameterizations, and results from the five NGA models for shallow crustal earthquakes in active tectonic regions are compared. A key difference in the data sets is the inclusion or exclusion of aftershocks. A comparison of the median spectral values for strike-slip earthquakes shows that they are within a factor of 1.5 for magnitudes between 6.0 and 7.0 for distances less than 100 km. The differences increase to a factor of 2 for M5 and M8 earthquakes, for buried ruptures, and for distances greater than 100 km. For soil sites, the differences in the modeling of soil/sediment depth effects increase the range in the median long-period spectral values for M7 strike-slip earthquakes to a factor of 3. The five models have similar standard deviations for M6.5-M7.5 earthquakes for rock sites and for soil sites at distances greater than 50 km. Differences in the standard deviations of up to 0.2 natural log units for moderate magnitudes at all distances and for large magnitudes at short distances result from the treatment of the magnitude dependence and the effects of nonlinear site response on the standard deviation.

scholarly journals Empirical Correlations between Peak Ground Velocity and Spectrum-Based Intensity Measures

2012 ◽  
Vol 28 (1) ◽  
pp. 17-35 ◽  
Author(s):  
Brendon A. Bradley
Keyword(s):  
Ground Motion ◽  
Peak Ground Velocity ◽  
Strongly Correlated ◽  
Correlation Equations ◽  
Ground Acceleration ◽  
Intensity Measures ◽  
Ground Motion Selection ◽  
Crustal Earthquakes ◽  
Short Period ◽  
Spectrum Intensity

Empirical correlation equations between peak ground velocity ( PGV) and several spectrum-based ground motion intensity measures are developed. The intensity measures examined in particular were: peak ground acceleration ( PGA), 5% damped pseudo-spectral acceleration ( SA), acceleration spectrum intensity ( ASI), and spectrum intensity ( SI). The computed correlations were obtained using ground motions from active shallow crustal earthquakes and four ground motion prediction equations. Results indicate that PGV is strongly correlated (i.e., a correlation coefficient of [Formula: see text]) with SI, moderately correlated with medium to long-period SA (i.e., [Formula: see text] for vibration periods 0.5-3.0 seconds), and also moderately correlated with short period SA, PGA and ASI ([Formula: see text]). A simple example is used to illustrate one possible application of the developed correlation equations for ground motion selection.

Ground-Motion Attenuation Model for Small-To-Moderate Shallow Crustal Earthquakes in California and Its Implications on Regionalization of Ground-Motion Prediction Models

2010 ◽  
Vol 26 (4) ◽  
pp. 907-926 ◽  
Author(s):  
Brian Chiou ◽  
Robert Youngs ◽  
Norman Abrahamson ◽  
Kofi Addo
Keyword(s):  
Ground Motion ◽  
Regional Differences ◽  
Regional Difference ◽  
Prediction Models ◽  
Motion Prediction ◽  
Ground Motion Prediction ◽  
Small Magnitude ◽  
Attenuation Model ◽  
Crustal Earthquakes ◽  
Active Tectonic

This paper presents the development of a ground-motion prediction model for small-to-moderate shallow crustal earthquakes (3M5.5, up to 200 km distance) using data from the California ShakeMap systems. Our goal is to provide an empirical model that can be confidently used in the investigation of ground-motion difference between California and other active tectonic regions (such as the Pacific Northwest and British Columbia, Canada) where the bulk of ground-motion data from shallow crustal earthquakes is in the small-to-moderate magnitude range. This attenuation model is developed as a small-magnitude extension of the Chiou and Youngs NGA model (CY2008). We observe, and incorporate into this model, a regional difference in median amplitude between central and southern California earthquakes. The strength of the regional difference diminishes with increasing spectral period. More importantly, it is magnitude dependent and becomes insignificant for M6 earthquakes, as indicated by the large-magnitude California data used in CY2008. Together, these findings have important implications on the practice of utilizing the regional differences observed in small-to-moderate earthquakes to infer the regional differences expected in large earthquakes, including the NGA model applicability in active tectonic regions outside California.

Damping Scaling Factors for Vertical Elastic Response Spectra for Shallow Crustal Earthquakes in Active Tectonic Regions

2014 ◽  
Vol 30 (3) ◽  
pp. 1335-1358 ◽  
Author(s):  
Sanaz Rezaeian ◽  
Yousef Bozorgnia ◽  
I. M. Idriss ◽  
Norman A. Abrahamson ◽  
Kenneth W. Campbell ◽  
...  
Keyword(s):  
Standard Deviation ◽  
Damping Ratio ◽  
Vertical Component ◽  
Vertical Motion ◽  
Horizontal Component ◽  
Elastic Response ◽  
Earthquake Ground Motion ◽  
Crustal Earthquakes ◽  
Elastic Response Spectra ◽  
Active Tectonic

This paper develops a new model for a damping scaling factor (DSF) that can be used to adjust elastic response spectral ordinates for the vertical component of earthquake ground motion at a 5% viscous damping ratio to ordinates at damping ratios between 0.5% and 30%. Using the extensive NGA-West2 database of recorded ground motions from worldwide shallow crustal earthquakes in active tectonic regions, a functional form for the median DSF is proposed that depends on the damping ratio, spectral period, earthquake magnitude, and distance. Standard deviation is a function of the damping ratio and spectral period. The proposed model is compared to the DSF for the “average” horizontal component. In general, the peak in DSF is shifted toward shorter periods and is farther from unity for the vertical component. Also, the standard deviation of DSF for vertical motion is slightly higher than that observed for the “average” horizontal component.

Summary of the ASK14 Ground Motion Relation for Active Crustal Regions

2014 ◽  
Vol 30 (3) ◽  
pp. 1025-1055 ◽  
Author(s):  
Norman A. Abrahamson ◽  
Walter J. Silva ◽  
Ronnie Kamai
Keyword(s):  
Ground Motion ◽  
Regional Differences ◽  
Hanging Wall ◽  
Nonlinear Effects ◽  
Motion Models ◽  
Crustal Earthquakes ◽  
Active Tectonic ◽  
Standard Deviations ◽  
Ground Motion Models ◽  
Directivity Effects

Empirical ground motion models for the average horizontal component from shallow crustal earthquakes in active tectonic regions are derived using the PEER NGA-West2 database. The model is applicable to magnitudes 3.0–8.5, distances 0–300 km, and spectral periods of 0–10 s. The model input parameters are the same as those used by Abrahamson and Silva (2008) , with the following exceptions: the loading level for nonlinear effects is based on the spectral acceleration at the period of interest rather than the PGA; and the distance scaling for hanging wall (HW) effects off the ends of the rupture includes a dependence on the source-to-site azimuth. Regional differences in large-distance attenuation and V S30 scaling between California, Japan, China, and Taiwan are included. The scaling for the HW effect is improved using constraints from numerical simulations. The standard deviation is magnitude-dependent, with smaller magnitudes leading to larger standard deviations at short periods, but smaller standard deviations at long periods. Directivity effects are not included through explicit parameters, but are captured through the variability of the empirical data.

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