scholarly journals Strong ground motion prediction for southwestern China from small earthquake records

2015 ◽  
Vol 3 (9) ◽  
pp. 5297-5323
Author(s):  
Z. R. Tao ◽  
X. X. Tao ◽  
A. P. Cui
Keyword(s):  
Ground Motion ◽  
Strong Ground Motion ◽  
Near Field ◽  
Seismic Hazard Assessment ◽  
Southwestern China ◽  
Small Earthquake ◽  
Earthquake Records ◽  
Strong Ground Motion Prediction ◽  
Ground Motion Records ◽  
Strong Ground

Abstract. For regions lack of strong ground motion records, a method is developed to predict strong ground motion by small earthquake records from local broadband digital earthquake networks. Sichuan and Yunnan regions, located in southwestern China, are selected as the targets. Five regional source and crustal medium parameters are inversed by micro-Genetic Algorithm. These parameters are adopted to predict strong ground motion for moment magnitude (Mw) 5.0, 6.0 and 7.0. Strong ground motion data are compared with the results, most of the result pass through ideally the data point plexus, except the case of Mw 7.0 in Sichuan region, which shows an obvious slow attenuation. For further application, this result is adopted in probability seismic hazard assessment (PSHA) and near-field strong ground motion synthesis of the Wenchuan Earthquake.

Kappa(κ) from Records of Small Earthquakes in North China

2014 ◽  
Vol 1065-1069 ◽  
pp. 1469-1473
Author(s):  
Zheng Ru Tao ◽  
Xia Xin Tao ◽  
Wen Qian Li
Keyword(s):  
Ground Motion ◽  
Strong Ground Motion ◽  
North China ◽  
Fourier Spectrum ◽  
Focal Depth ◽  
Mean Value ◽  
Small Earthquake ◽  
Ground Motion Records ◽  
Seismograph Network ◽  
Strong Ground

At high frequencies, there is an obvious descending of Fourier spectrum amplitude of ground motion acceleration. This fact could be described by a low0pass filter that is controlled by parameter Kappa (κ). In most regions of the world, there are not sufficient strong ground motion records to evaluate this regional parameter. We try to acquire κ value from small-earthquake records of the broadband digital seismograph network in North China (36°-43°N, 113°-120°E). Total 1995 records from 28 small earthquakes (Mw=3.5-4.5) recorded at 155 stations of China Earthquake Network during February of 2002 to September of 2012, are analyzed. The κ value is acquired from the slope rate of the decay segment of the calculated Fourier spectrum of each record, and the mean value is obtained. The result is analyzed if κ is magnitude, focal depth or distance dependent. For the magnitude-dependence, κ values of 40 strong ground motion records are also obtained and compared. The result of the paper shows that κ is not magnitude-dependent neither focal depth-dependent. The distance-dependent is not obvious, especially for small earthquake.

Identification of Near-Field Pulse-Like Ground Motions Recorded at Bajiao Station during the Mainshock of the Great Wenchuan Earthquake

2011 ◽  
Vol 250-253 ◽  
pp. 2546-2553 ◽  
Author(s):  
Chun Feng Li ◽  
Yong Bo Li
Keyword(s):  
Wenchuan Earthquake ◽  
Ground Motion ◽  
Strong Ground Motion ◽  
Ground Motions ◽  
Near Field ◽  
Velocity Pulse ◽  
Field Pulse ◽  
Near Fault ◽  
Ground Motion Records ◽  
Strong Ground

When earthquake occurs, it is in near-fault that the most serious damage happens and velocity pulse appears. Velocity pulse could have huge potential to destroy the structure in near-fault. The set of records at Bajiao Station is one of the three famous near-field sets of strong ground motion records whose PGAs are the largest in all the sets of records obtained from the mainshock of the Great Wenchuan Earthquake. Our research is to identify the pulse-like characteristics from the set of records at Bajiao Station. It is found that velocity pulses in the records are “hidden pulses”.

Special Issue on Strong Ground Motion Prediction and Seismic Hazard Assessment

2013 ◽  
Vol 8 (5) ◽  
pp. 847-847
Author(s):  
Hiroyuki Fujiwara
Keyword(s):  
Seismic Hazard ◽  
Ground Motion ◽  
Hazard Assessment ◽  
Strong Ground Motion ◽  
Seismic Hazard Assessment ◽  
Hazard Maps ◽  
Special Issue ◽  
Strong Ground Motion Prediction ◽  
Large Earthquakes ◽  
Strong Ground

We have been conducting seismic hazard assessment for Japan under the guidance of the Headquarters for Earthquake Research Promotion of Japan since the 1995 Hyogo-ken Nanbu Earthquake, and have made National Seismic Hazard Maps for Japan for use in estimating strong ground motion caused by future earthquakes. This special issue reviews the results of these efforts. Such work includes the development of seismic hazard assessment methodology for Japan, highly accurate prediction techniques for strong seismic ground motion and modeling underground structures for evaluating strong ground motion. Related research on utilization initiatives and risk assessment based on hazard information has also been conducted. An open Web system – the Japan Seismic Hazard Information Station (J-SHIS) – has even been developed to provide information interactively. The 2011 Mw9.0 Great East Japan Earthquake was the largest such event recorded in the history of Japan. This megathrust earthquake was not considered in National Seismic Hazard Maps for Japan. But efforts toward revising seismic hazard assessment in Japan are progressing based on lessons learned from this earthquake. Hazard assessment is currently being reviewed in relation to the large earthquakes anticipated to occur in the near future based in the Sagami Trough and the Nankai Trough in the waters of offshore Japan. This assessment, which considers earthquakes larger than those assumed to have occurred in the past, is being reviewed as of this writing. In light of these pressing circumstances, studies are now being implemented to evaluate the long-period ground motion accompanying these large earthquakes. The knowledge that has been cultivated in Japan in terms of seismic hazard assessment has reached a high level, and it is important to expand such knowledge both internationally and domestically. This is just one of the reasons that efforts here in Japan are being made to help improve the level of seismic hazard assessment in the Asian region and throughout the entire world. It is expected that this special issue will help contribute to the further development of strong ground motion prediction and seismic hazard assessment now and in the future. Finally, I extend our sincere thanks to all of the contributors and reviewers involved with these articles.

scholarly journals Near-Field Ground Motion Modal versus Wave Propagation Analysis

2010 ◽  
Vol 17 (4-5) ◽  
pp. 611-617 ◽  
Author(s):  
Artur Cichowicz
Keyword(s):  
Ground Motion ◽  
Strong Ground Motion ◽  
Response Spectrum ◽  
Near Field ◽  
Spectral Characteristics ◽  
Beam Model ◽  
Drift Spectrum ◽  
Localized Deformation ◽  
Dominant Period ◽  
Strong Ground

The response spectrum generally provides a good estimate of the global displacement and acceleration demand of far-field ground motion on a structure. However, it does not provide accurate information on the local shape or internal deformation of the response of the structure. Near-field pulse-like ground motion will propagate through the structure as waves, causing large, localized deformation. Therefore, the response spectrum alone is not a sufficient representation of near-field ground motion features. Results show that the drift-response technique based on a continuous shear-beam model has to be employed here to estimate structure-demand parameters when structure is exposed to the pulse like ground motion. Conduced modeling shows limited applicability of the drift spectrum based on the SDOF approximation. The SDOF drift spectrum approximation can only be applied to structures with smaller natural periods than the dominant period of the ground motion. For periods larger than the dominant period of ground motion the SDOF drift spectra model significantly underestimates maximum deformation. Strong pulse-type motions are observed in the near-source region of large earthquakes; however, there is a lack of waveforms collected from small earthquakes at very close distances that were recorded underground in mines. The results presented in this paper are relevant for structures with a height of a few meters, placed in an underground excavation. The strong ground motion sensors recorded mine-induced earthquakes in a deep gold mine, South Africa. The strongest monitored horizontal ground motion was caused by an event of magnitude 2 at a distance of 90 m with PGA 123 m/s2, causing drifts of 0.25%–0.35%. The weak underground motion has spectral characteristics similar to the strong ground motion observed on the earth's surface; the drift spectrum has a maximum value less than 0.02%.

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