scholarly journals New Ground Motion to Intensity Conversion Equations for China

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.

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

2019 ◽  
Author(s):  
Mengyao Sun ◽  
Huiyu Zhu ◽  
Jie Zhang ◽  
Haohuan Fu ◽  
Xiao Tian
Keyword(s):  
Ground Motion ◽  
Yunnan Province ◽  
Strong Motion ◽  
Spectral Ratio ◽  
Prediction Equation ◽  
Peak Ground Velocity ◽  
Induced Earthquakes ◽  
Ground Acceleration ◽  
Hypocentral Distance ◽  
Fundamental Frequencies

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.

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

2020 ◽  
Vol 92 (1) ◽  
pp. 448-459 ◽  
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.

A Seismic Intensity Survey of the 16 April 2016 Mw 7.8 Pedernales, Ecuador, Earthquake: A Comparison with Strong-Motion Data and Teleseismic Backprojection

2021 ◽  
Author(s):  
Ellen M. Smith ◽  
Walter D. Mooney
Keyword(s):  
Emergency Response ◽  
Strong Motion ◽  
Seismic Intensity ◽  
Peak Ground Velocity ◽  
Ground Acceleration ◽  
Motion Data ◽  
Contour Maps ◽  
Crustal Earthquakes ◽  
Maximum Value ◽  
Large Earthquakes

Abstract We conducted a seismic intensity survey in Ecuador, following the 16 April 2016 Mw 7.8 Pedernales earthquake, to document the level of damage caused by the earthquake. Our modified Mercalli intensities (MMIs) reach a maximum value of VIII along the coast, where single, two, and multistory masonry and concrete designed buildings partially or completely collapsed. The contours of our MMI maps are similar in shape to the contour maps of peak ground acceleration (PGA) and peak ground velocity (PGV). A comparison of our seismic intensities with the recorded PGA and PGV values reveals that our MMI values are lower than predicted by ground-motion intensity conversion equations that are based on shallow crustal earthquakes. The image of the earthquake rupture obtained using teleseismic backprojection at 0.5–2.0 Hz is coincident with the region of maximum MMI, PGA, and PGV values, Thus, rapid calculation of backprojection may be a useful tool for guiding the deployment of emergency response teams following large earthquakes. The most severe damage observed was, primarily, due to a combination of poorly constructed buildings and site conditions.

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

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&gt;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.

The ShakeOut Earthquake Source and Ground Motion Simulations

2011 ◽  
Vol 27 (2) ◽  
pp. 273-291 ◽  
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).

scholarly journals Attenuation relationships of peak ground motions in the Jazan Region

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.

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

2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
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.

Nonlinear Site Effects from the 30 November 2018 Anchorage, Alaska, Earthquake

2021 ◽  
Author(s):  
John D. Thornley ◽  
Utpal Dutta ◽  
John Douglas ◽  
Zhaohui (Joey) Yang
Keyword(s):  
Site Response ◽  
Strong Motion ◽  
North American Plate ◽  
Peak Ground Velocity ◽  
Reference Station ◽  
Earthquake Hazards ◽  
Ground Acceleration ◽  
Nonlinear Site Response ◽  
Generalized Inversion Technique ◽  
Versus Peak

ABSTRACT Anchorage, Alaska, is a natural laboratory for recording strong ground motions from a variety of earthquake sources. The city is situated in a tectonic region that includes the interface and intraslab earthquakes related to the subducting Pacific plate and crustal earthquakes from the upper North American plate. The generalized inversion technique was used with a local rock reference station to develop site response at &gt;20 strong-motion stations in Anchorage. A database of 94 events recorded at these sites from 2005 to 2019 was also compiled and processed to compare their site response with those in the 2018 Mw 7.1 event (main event). The database is divided into three datasets, including 75 events prior to the main event, the main event, and 19 aftershocks. The stations were subdivided into the site classes defined in the National Earthquake Hazards Reduction Program based on estimated average shear-wave velocity in of the upper 30 m (VS30), and site-response results from the datasets were compared. Nonlinear site response was observed at class D and DE sites (VS30 of 215–300 and 150–215  m/s, respectively) but not at class CD and C sites (VS30 of 300–440 and 440–640  m/s, respectively). The relationship of peak ground acceleration versus peak ground velocity divided by VS30 (shear-strain proxy) was shown to further support the observation that sites with lower VS30 experienced nonlinear site response.

Strong ground motion of mine tremors: Some implications for near-source ground motion parameters

1981 ◽  
Vol 71 (1) ◽  
pp. 295-319
Author(s):  
A. McGarr ◽  
R. W. E. Green ◽  
S. M. Spottiswoode
Keyword(s):  
Ground Motion ◽  
Source Parameters ◽  
Seismic Source ◽  
Shear Velocity ◽  
Recording System ◽  
Ground Acceleration ◽  
Hypocentral Distance ◽  
Earthquake Size ◽  
Mine Tremors ◽  
Stress Drops

abstract Ground acceleration was recorded at a depth of about 3 km in the East Rand Proprietary Mines, South Africa, for tremors with −1 ≦ ML ≦ 2.6 in the hypocentral distance range 50 m &lt; R ≦ 1.6 km. The accelerograms typically had predominant frequencies of several hundred Hertz and peak accelerations, a, as high as 12 g. The peak accelerations show a dependence on magnitude, especially when expressed as dynamic shear-stress differences, defined as σ˜ = ρRa, where ρ is density. For the mine tremors, σ˜ varies from 2 to 500 bars and depends on magnitude according to log σ˜ = 1.40 + 0.38 · ML. Accelerograms for 12 events were digitized and then processed to determine velocity and, for seven events with especially good S/N, displacement and seismic source parameters. Peak ground velocities v ranged up to 6 cm/sec and show a well-defined dependence one earthquake size as measured by ML or by seismic moment, Mo. On the basis of regression fits to the mine data, with −0.76 ≦ ML ≦ 1.45, log Rv = 3.95 + 0.57 ML, where Rv is in cm2/sec, and log Rv = −4.68 + 0.49 log Mo. These regression lines agree excellently with the corresponding data for earthquakes of ML up to 6.4 or Mo to 1.4 × 1026 dyne-cm. At a given value of ML or Mo, a, at fixed R, shows considerably greater variation than v and appears to depend on the bandwidth of the recording system. The peak acceleration at small hypocentral distances is broadly consistent with ρRa = 1.14 Δτrofs/β, where Δτ is stress drop, ro is the source radius, β is shear velocity, and fs is the bandwidth of the recording system. The peak velocity data agree well with Rv = 0.57 βΔτro/μ, where μ is the modulus of rigidity; both expressions follow from Brune's model of the seismic source and were compared with data for events in the size range 5 × 1016 ≦ Mo ≦ 1.4 × 1026 dyne-cm. Measurements of the source parameters indicated that, as for earthquakes, the stress drops for the tremors range from 1 to 100 bars and show no consistent dependence on Mo down to Mo = 5 × 1016 dyne-cm.

scholarly journals ShakeMaps during the Emilia sequence

2012 ◽  
Vol 55 (4) ◽  
Author(s):  
Valentino Lauciani ◽  
Licia Faenza ◽  
Alberto Michelini
Keyword(s):  
Software Package ◽  
Civil Defense ◽  
Peak Ground Velocity ◽  
Accurate Information ◽  
Ground Acceleration ◽  
Ground Shaking ◽  
Peak Ground Motion ◽  
Emilia Romagna Region ◽  
Fully Automatic ◽  
Definition Of

<p>ShakeMap is a software package that can be used to generate maps of ground shaking for various peak ground motion (PGM) parameters, including peak ground acceleration (PGA), peak ground velocity, and spectral acceleration response at 0.3 s, 1.0 s and 3.0 s, and instrumentally derived intensities. ShakeMap has been implemented in Italy at the Istituto Nazionale di Geofisica e Vulcanologia (INGV; National Institute of Geophysics and Volcanology) since 2006 (http://shakemap.rm.ingv.it), with the primary aim being to help the Dipartimento della Protezione Civile (DPC; Civil Protection Department) civil defense agency in the definition of rapid and accurate information on where earthquake damage is located, to correctly direct rescue teams and to organize emergency responses. Based on the ShakeMap software package [Wald et al. 1999, Worden et al. 2010], which was developed by the U.S. Geological Survey (USGS), the INGV is constructing shake maps for Ml ≥3.0, with the adoption of a fully automatic procedure based on manually revised locations and magnitudes [Michelini et al. 2008]. The focus of this study is the description of the progressive generation of these shake maps for the sequence that struck the Emilia-Romagna Region in May 2012. […]</p><br />

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