Ground Motion from Mw 1.5 to 3.9 Aftershocks of the 2014 Mw 6.2 Jinggu Earthquake at Hypocentral Distances < 45 km in Yunnan, China

ABSTRACT The ground motion from small aftershocks of the 2014 Mw 6.2 Jinggu earthquake in Yunnan Province is analyzed. With the seismic records, we assess the site conditions and develop a ground‐motion prediction equation (GMPE) for this region. The strong‐motion duration is also calculated to further understand the potential seismic hazard to nearby structures. The dataset includes 504 events with Mw 1.5–3.9 and 2956 three‐component records at hypocentral distances <45 km from 10 stations operated by the Earthquake Administration of Yunnan Province. The ground‐motion amplification factor derived from the horizontal‐to‐vertical (H/V) spectral ratio of each station ranges from 1.1 to 5.2 (0.04–0.72 in log units). The time‐averaged shear‐wave velocity to 30 m depth (VS30) for seismographic stations is estimated using fundamental frequencies associated with peak H/V ratios. GMPE is obtained using the entire dataset. The values of the geometrical spreading coefficient for the pseudoabsolute response spectral acceleration (PSA) at a frequency of 10 Hz suggest higher decay than those for the peak ground velocity, peak ground acceleration (PGA), and PSA at other frequencies. The significant duration (Ds) of strong ground motion systematically decreases with PGA but increases with hypocentral distance. However, no strong correlation is observed for Ds and magnitude or for Ds and VS30. The results of this study are compared with analogous research (Babaie Mahani and Kao, 2018) on induced earthquakes with the same distance–magnitude range. The comparison indicates that the decay of ground‐motion amplitudes with hypocentral distance in our case is generally lower than that in the other study. The Ds trends are consistent in the two studies, although the longest strong‐motion duration in the two cases apparently differs.

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New Ground Motion to Intensity Conversion Equations for China

Shock and Vibration ◽

10.1155/2021/5530862 ◽

2021 ◽

Vol 2021 ◽

pp. 1-21

Author(s):

Xiufeng Tian ◽

Zengping Wen ◽

Weidong Zhang ◽

Jie Yuan

Keyword(s):

Ground Motion ◽

Correction Term ◽

Strong Motion ◽

Seismic Intensity ◽

Peak Ground Velocity ◽

Ground Acceleration ◽

Strong Earthquakes ◽

Hypocentral Distance ◽

Peak Ground Motion ◽

Pseudo Spectral

In this study, we use the strong motion records and seismic intensity data from 11 moderate-to-strong earthquakes in the mainland of China since 2008 to develop new conversion equations between seismic intensity and peak ground motion parameters. Based on the analysis of the distribution of the dataset, the reversible conversion relationships between modified Mercalli intensity (MMI) and peak ground acceleration (PGA), peak ground velocity (PGV), and pseudo-spectral acceleration (PSA) at natural vibration periods of 0.3 s, 1.0 s, 2.0 s, and 3.0 s are obtained by using the orthogonal regression. The influence of moment magnitude, hypocentral distance, and hypocentral depth on the residuals of conversion equations is also explored. To account for and eliminate the trends in the residuals, we introduce a magnitude-distance-depth correction term and obtain the improved relationships. Furthermore, we compare the results of this study with previously published works and analyze the regional dependence of conversion equations. To quantify the regional variations, a regional correction factor for China, suitable for adjustment of global relationships, has also been estimated.

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New Ground Motion to Intensity Conversion Equations (GMICEs) for New Zealand

Seismological Research Letters ◽

10.1785/0220200156 ◽

2020 ◽

Vol 92 (1) ◽

pp. 448-459 ◽

Cited By ~ 1

Author(s):

Jose M. Moratalla ◽

Tatiana Goded ◽

David A. Rhoades ◽

Silvia Canessa ◽

Matthew C. Gerstenberger

Keyword(s):

New Zealand ◽

Ground Motion ◽

Strong Motion ◽

Peak Ground Velocity ◽

Least Squares Regression ◽

Data Types ◽

Ground Acceleration ◽

Hypocentral Distance ◽

Motion Data ◽

Recent Earthquakes

Abstract Macroseismic intensities play a key role in the engineering, seismological, and loss modeling communities. However, at present, there is an increasing demand for instrumental data-based loss estimations that require statistical relationships between intensities and strong-motion data. In New Zealand, there was an urgent need to update the ground motion to intensity conversion equation (GMICE) from 2007, developed prior to a large number of recent earthquakes including the 2010–2011 Canterbury and 2016 Kaikōura earthquake sequences. Two main factors now provide us with the opportunity to update New Zealand’s GMICE: (1) recent publication of New Zealand’s Strong-Motion Database, corresponding to 276 New Zealand earthquakes with magnitudes 3.5–7.8 and 4–185 km depths; and (2) recent generation of a community intensity database from GeoNet’s “Felt Classic” (2004–2016) and “Felt Detailed” (2016–2019) questionnaires, corresponding to around 930,000 individual reports. Ground-motion data types analyzed are peak ground velocity (PGV) and peak ground acceleration (PGA). The intensity database contains 67,572 felt reports from 917 earthquakes, with magnitudes 3.5–8.1, and 1797 recordings from 247 strong-motion stations (SMSs), with hypocentral distances of 5–345 km. Different regression analyses were tested, and the bilinear regression of binned mean strong-motion recordings for 0.5 modified Mercalli intensity bins was selected as the most appropriate. Total least squares regression was chosen for reversibility in the conversions. PGV provided the best-fitting results, with lower standard deviations. The influence of hypocentral distance, earthquake magnitude, and the site effects of local geology, represented by the mean shear-wave velocity in the first 30 m depth, on the residuals was also explored. A regional correction factor for New Zealand, suitable for adjustment of global relationships, has also been estimated.

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Attenuation relationships of peak ground motions in the Jazan Region

Arabian Journal of Geosciences ◽

10.1007/s12517-020-06442-z ◽

2021 ◽

Vol 14 (3) ◽

Author(s):

Ali K. Abdelfattah ◽

Abdullah Al-amri ◽

Kamal Abdelrahman ◽

Muhamed Fnais ◽

Saleh Qaysi

Keyword(s):

Saudi Arabia ◽

Ground Motions ◽

Prediction Equation ◽

Peak Ground Velocity ◽

Local Magnitude ◽

Ground Acceleration ◽

Data Set ◽

Hypocentral Distance ◽

Distance Range ◽

Attenuation Relationships

AbstractIn this study, attenuation relationships are proposed to more accurately predict ground motions in the southernmost part of the Arabian Shield in the Jazan Region of Saudi Arabia. A data set composed of 72 earthquakes, with normal to strike-slip focal mechanisms over a local magnitude range of 2.0–5.1 and a distance range of 5–200 km, was used to investigate the predictive attenuation relationship of the peak ground motion as a function of the hypocentral distance and local magnitude. To obtain the space parameters of the empirical relationships, non-linear regression was performed over a hypocentral distance range of 4–200 km. The means of 638 peak ground acceleration (PGA) and peak ground velocity (PGV) values calculated from the records of the horizontal components were used to derive the predictive relationships of the earthquake ground motions. The relationships accounted for the site-correlation coefficient but not for the earthquake source implications. The derived predictive attenuation relationships for PGV and PGA are$$ {\log}_{10}(PGV)=-1.05+0.65\cdotp {M}_L-0.66\cdotp {\log}_{10}(r)-0.04\cdotp r, $$ log 10 PGV = − 1.05 + 0.65 · M L − 0.66 · log 10 r − 0.04 · r , $$ {\log}_{10}(PGA)=-1.36+0.85\cdotp {M}_L-0.85\cdotp {\log}_{10}(r)-0.005\cdotp r, $$ log 10 PGA = − 1.36 + 0.85 · M L − 0.85 · log 10 r − 0.005 · r , respectively. These new relationships were compared to the grand-motion prediction equation published for western Saudi Arabia and indicate good agreement with the only data set of observed ground motions available for an ML 4.9 earthquake that occurred in 2014 in southwestern Saudi Arabia, implying that the developed relationship can be used to generate earthquake shaking maps within a few minutes of the event based on prior information on magnitudes and hypocentral distances taking into considerations the local site characteristics.

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Localizing Ground-Motion Models in Volcanic Terranes: Shallow Events at Mt. Etna, Italy, Revisited

Bulletin of the Seismological Society of America ◽

10.1785/0120190325 ◽

2020 ◽

Vol 110 (6) ◽

pp. 2843-2861

Author(s):

Giuseppina Tusa ◽

Horst Langer ◽

Raffaele Azzaro

Keyword(s):

Ground Motion ◽

Hazard Analysis ◽

Total Error ◽

Scaling Law ◽

Peak Ground Velocity ◽

Ground Acceleration ◽

Hypocentral Distance ◽

Motion Models ◽

Mt Etna ◽

Ground Motion Models

ABSTRACT We present a set of revised ground-motion models (GMMs) for shallow events at Mt. Etna Volcano. The recent occurrence of damaging events, in particular two of the strongest earthquakes ever instrumentally recorded in the area, has required revising previous GMMs, as these failed to match the observations made for events with local magnitude ML>4.3, above all for sites situated close to the epicenter. The dataset now includes 49 seismic events, with a total of 1600 time histories recorded at distances of up to 100 km, and ML ranging from 3.0 to 4.8. The model gives estimates of peak ground acceleration (both horizontal and vertical), peak ground velocity (both horizontal and vertical), and 5% damped horizontal pseudoacceleration response spectral ordinates up to a period of 4 s. GMMs were developed using the functional form proposed by Boore and Atkinson (2008). Furthermore, with a slightly modified approach, we also considered a regression model using a pseudodepth (h) depending on magnitude according to the scaling law by Azzaro et al. (2017). Both models were applied to hypocentral distance ranges of up to 60 km and up to 100 km, respectively. From the statistical analysis, we found that reducing the maximum distance from the event up to 60 km and introducing a magnitude-dependent pseudodepth improved the model in terms of total error. We compared our results with those derived using the GMMs for shallow events at Mt. Etna found by Tusa and Langer (2016) and for volcanic areas by Lanzano and Luzi (2019). The main differences are observed at short epicentral distances and for higher magnitude events. The use of variable pseudodepth avoids sharp peaks of predicted ground-motion parameters around the epicenter, preventing instabilities when using a GMM in probabilistic seismic hazard analysis.

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Earthquake ground shaking hazard assessment for the Lower Hutt and Porirua areas, New Zealand

Bulletin of the New Zealand Society for Earthquake Engineering ◽

10.5459/bnzsee.25.4.286-302 ◽

1992 ◽

Vol 25 (4) ◽

pp. 286-302 ◽

Cited By ~ 10

Author(s):

R. J. Van Dissen ◽

J. J. Taber ◽

W. R. Stephenson ◽

S. Sritheran ◽

S. A. L. Read ◽

...

Keyword(s):

Ground Motion ◽

Strong Motion ◽

Spectral Ratio ◽

Fine Sand ◽

Geographic Variations ◽

Ground Acceleration ◽

Ground Shaking ◽

Earthquake Scenarios ◽

Shear Wave Velocities ◽

Strong Ground

Geographic variations in strong ground shaking expected during damaging earthquakes impacting on the Lower Hutt and Porirua areas are identified and quantified. Four ground shaking hazard zones have been mapped in the Lower Hutt area, and three in Porirua, based on geological, weak motion, and strong motion inputs. These hazard zones are graded from 1 to 5. In general, Zone 5 areas are subject to the greatest hazard, and Zone 1 areas the least. In Lower Hutt, zones 3 and 4 are not differentiated and are referred to as Zone 3-4. The five-fold classification is used to indicate the range of relative response. Zone 1 areas are underlain by bedrock. Zone 2 areas are typically underlain by compact alluvial and fan gravel. Zone 3-4 is underlain, to a depth of 20 m, by interfingered layers of flexible (soft) sediment (fine sand, silt, clay, peat), and compact gravel and sand. Zone 5 is directly underlain by more than 10 m of flexible sediment with shear wave velocities in the order of 200 m/s or less. The response of each zone is assessed for two earthquake scenarios. Scenario 1 is for a moderate to large, shallow, distant earthquake that results in regional Modified Mercalli intensity V-VI shaking on bedrock. Scenario 2 is for a large, local, but rarer, Wellington fault earthquake. The response characterisation for each zone comprises: expected Modified Mercalli intensity; peak horizontal ground acceleration; duration of strong shaking; and amplification of ground motion with respect to bedrock, expressed as a Fourier spectral ratio, including the frequency range over which the most pronounced amplification occurs. In brief, high to very high ground motion amplifications are expected in Zone 5, relative to Zone 1, during a scenario 1 earthquake. Peak Fourier spectral ratios of 10-20 are expected in Zone 5, relative to Zone 1, and a difference of up to three, possibly four, MM intensity units is expected between the two zones. During a scenario 2 event, it is anticipated that the level of shaking throughout the Lower Hutt and Porirua region will increase markedly, relative to scenario 1, and the average difference in shaking between each zone will decrease.

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The ShakeOut Earthquake Source and Ground Motion Simulations

Earthquake Spectra ◽

10.1193/1.3570677 ◽

2011 ◽

Vol 27 (2) ◽

pp. 273-291 ◽

Cited By ~ 30

Author(s):

Robert W. Graves ◽

Brad T. Aagaard ◽

Kenneth W. Hudnut

Keyword(s):

Ground Motion ◽

Ground Motions ◽

Strong Motion ◽

Peak Ground Velocity ◽

Motion Modeling ◽

Ground Acceleration ◽

San Andreas ◽

Basin Effects ◽

Simulated Ground Motions ◽

D Model

The ShakeOut Scenario is premised upon the detailed description of a hypothetical Mw 7.8 earthquake on the southern San Andreas Fault and the associated simulated ground motions. The main features of the scenario, such as its endpoints, magnitude, and gross slip distribution, were defined through expert opinion and incorporated information from many previous studies. Slip at smaller length scales, rupture speed, and rise time were constrained using empirical relationships and experience gained from previous strong-motion modeling. Using this rupture description and a 3-D model of the crust, broadband ground motions were computed over a large region of Southern California. The largest simulated peak ground acceleration (PGA) and peak ground velocity (PGV) generally range from 0.5 to 1.0 g and 100 to 250 cm/s, respectively, with the waveforms exhibiting strong directivity and basin effects. Use of a slip-predictable model results in a high static stress drop event and produces ground motions somewhat higher than median level predictions from NGA ground motion prediction equations (GMPEs).

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Estimation of ground motion in Xalapa, Veracruz, Mexico during the 1920 (M~6.4) crustal earthquake, and some significant intraslab earthquakes of the last century

Geofísica Internacional ◽

10.22201/igeof.00167169p.2018.57.2.2039 ◽

2018 ◽

Vol 57 (2) ◽

Author(s):

Francisco Córdoba-Montiel Córdoba-Montiel ◽

Srhi Krishna Singh ◽

Arturo Iglesias ◽

Xyoli Pérez-Campos ◽

K. Sieron

Keyword(s):

Ground Motion ◽

Stress Drop ◽

Seismic Waves ◽

Volcanic Belt ◽

Spectral Ratio ◽

Site Effect ◽

Peak Ground Velocity ◽

Ground Acceleration ◽

Scenario Earthquakes ◽

The City

Ground motions in Xalapa, Veracruz, Mexico, during the earthquake of January 4, 1920 (M~6.4), and three significant intraslab earthquakes (Mw7.0) of the last century were estimated. These events are reasonable scenario earthquakes for Xalapa. Towards this goal, portable broadband seismographs at nine sites in the city and an additional one at a reference hard site outside the city were deployed. Peak ground acceleration (Amax) and peak ground velocity (Amax) in Xalapa were estimated based on Brune w -2 source model and the site effect, obtained from earthquake recordings by using the standard spectral ratio (SSR) technique, and the application of a stochastic method. During the 1920 Xalapa earthquake the estimated Amax values corresponding to a stress drop, Ds, of 50 bar are between 100 and 250 cm/s2, except at two sites where the site effect is very large and Amax values reach 300 and 600 cm/s2. Estimated Vmax values are between 10 and 20 cm/s, except at the site with the largest site effect where it is ~ 40 cm/s. Ds of 30 and 100 bar produce about half and twice of these peak values, respectively. The main uncertainty in the present estimations is due the Ds value, because although a range of 30 to 100 bar for crustal earthquakes in the Trans-Mexican Volcanic Belt (in which Xalapa is located) seems reasonable, it is not constrained by the data. The mean stress drop for intraslab events, ~ 300 bar, is better constrained from previous studies. A median Amax of ~ 30 cm/s2 and a median Vmax of 4 cm/s in Xalapa during the 1973 (Orizaba) and 1999 (Tehuacán) earthquakes was estimated; the corresponding values during the 1980 (Huajuapan) earthquake are ~ 10 cm/s2 and 2 cm/s. The uncertainty in the estimation is probably within a factor of 2 to 3.The ground motion prediction equations developed from data in the forearc region with less attenuation (than the backarc region) and recorded at hard sites appear to work reasonably well for Xalapa sites, which lie in the back arc. This observation suggests that the seismic waves from intraslab earthquakes, traveling through the mantle wedge before arriving Xalapa, suffer relatively large attenuation. However, these waves get amplified due to local site effects. It seems that in Xalapa these two effects, roughly, balance each other.

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Ground motion prediction model for southeastern México removing site effects using the Earthquake horizontal-to-vertical ratio (EHVSR)

Geofísica Internacional ◽

10.22201/igeof.00167169p.2020.59.4.1894 ◽

2020 ◽

Vol 59 (4) ◽

pp. 257-272

Author(s):

Javier Lermo-Samaniego

Keyword(s):

Ground Motion ◽

Site Effects ◽

Spectral Ratio ◽

Site Effect ◽

Prediction Equation ◽

Reliable Estimate ◽

Motion Prediction ◽

Ground Motion Prediction ◽

Attenuation Model ◽

Hypocentral Distance

We propose a ground motion attenuation model (ground motion prediction equation, GMPE) for Southeast Mexico. We suppress site effects obtained from Earthquake Horizontal to Vertical Spectral Ratio (EHVSR) as a reliable estimate of site effects. (The attenuation model was built as a function of magnitude and hypocentral distance)). We used 86 seismic events with 5.0 ? Mw ? 8.2 (earthquake recordings for the 9/7/2017, Mw8.2 Tehuantepec earthquake are included), and distances between 52 ? R ? 618 km. They were recorded in nine stations of the Engineering Institute of the National Autonomous University of Mexico (II-UNAM) accelerometric network installed in the states of Chiapas, Oaxaca, Tabasco and Veracruz. Site effects at each of these stations were estimated by using the average EHVSR. Then, by means of this spectral ratio the site effects were suppressed at each station and for every record. This work points out the need to remove the site effect in the GMPE. The current models overestimate this effect.

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Seismic Hazard Assessment for the Tianshui Urban Area, Gansu Province, China

International Journal of Geophysics ◽

10.1155/2012/461863 ◽

2012 ◽

Vol 2012 ◽

pp. 1-10 ◽

Cited By ~ 3

Author(s):

Zhenming Wang ◽

David T. Butler ◽

Edward W. Woolery ◽

Lanmin Wang

Keyword(s):

Seismic Hazard ◽

Ground Motion ◽

Seismic Design ◽

Hazard Analysis ◽

Seismic Hazard Assessment ◽

Gansu Province ◽

Mitigation Measures ◽

Peak Ground Velocity ◽

Ground Acceleration ◽

Acceleration Time Histories

A scenario seismic hazard analysis was performed for the city of Tianshui. The scenario hazard analysis utilized the best available geologic and seismological information as well as composite source model (i.e., ground motion simulation) to derive ground motion hazards in terms of acceleration time histories, peak values (e.g., peak ground acceleration and peak ground velocity), and response spectra. This study confirms that Tianshui is facing significant seismic hazard, and certain mitigation measures, such as better seismic design for buildings and other structures, should be developed and implemented. This study shows that PGA of 0.3 g (equivalent to Chinese intensity VIII) should be considered for seismic design of general building and PGA of 0.4 g (equivalent to Chinese intensity IX) for seismic design of critical facility in Tianshui.

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Near-Source Simulation of Strong Ground Motion in Amatrice Downtown Including Site Effects

Geosciences ◽

10.3390/geosciences11050186 ◽

2021 ◽

Vol 11 (5) ◽

pp. 186

Author(s):

Alessandro Todrani ◽

Giovanna Cultrera

Keyword(s):

Ground Motion ◽

Site Effects ◽

Central Italy ◽

Strong Motion ◽

Seismic Source ◽

Spectral Ratio ◽

Intensity Measures ◽

Standard Spectral Ratio ◽

Heavy Damage ◽

Strong Ground

On 24 August 2016, a Mw 6.0 earthquake started a damaging seismic sequence in central Italy. The historical center of Amatrice village reached the XI degree (MCS scale) but the high vulnerability alone could not explain the heavy damage. Unfortunately, at the time of the earthquake only AMT station, 200 m away from the downtown, recorded the mainshock, whereas tens of temporary stations were installed afterwards. We propose a method to simulate the ground motion affecting Amatrice, using the FFT amplitude recorded at AMT, which has been modified by the standard spectral ratio (SSR) computed at 14 seismic stations in downtown. We tested the procedure by comparing simulations and recordings of two later mainshocks (Mw 5.9 and Mw 6.5), underlining advantages and limits of the technique. The strong motion variability of simulations was related to the proximity of the seismic source, accounted for by the ground motion at AMT, and to the peculiar site effects, described by the transfer function at the sites. The largest amplification characterized the stations close to the NE hill edge and produced simulated values of intensity measures clearly above one standard deviation of the GMM expected for Italy, up to 1.6 g for PGA.

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