Seismic Hazard Assessment of Hengshui Area by the Modified Stochastic Finite Fault Modeling

2015 ◽  
Vol 744-746 ◽  
pp. 894-897
Author(s):  
Bo Yan Liu ◽  
Wen Hao Shen ◽  
Bao Ping Shi

In recent years, numerical simulation of strong ground motion has been well developed with the progress of earthquake science, and it has become an important approach to estimate strong ground motion. In this research, we improve the original program of EXSIM and the modified program named MEXSIM to calculate the Peak Ground Acceleration (PGA) and Peak Ground Velocity (PGV) which is essential for seismic hazard assessment of Hengshui area. Considering the impact of V30(the average shear-velocity down to 30 m) we calculate the impact of two scenario earthquakes from the rupture processes of Hengshui fault and Qianmotou fault. Comparing to Qianmotou scenario earthquake, if the instability fault is Hengshui fault, the PGA and PGV could be 200-360gal and 20-35cm/s respectively in Hengshui city.

2007 ◽  
Vol 01 (02) ◽  
pp. 99-118 ◽  
Author(s):  
JEROEN TROMP

We provide an overview of some of the issues that need to be considered in the context of quantitative seismic hazard assessment. To begin with, one needs to inventory and characterize the major faults that could produce earthquakes that would impact the region of interest. Next, one needs a seismographic network that continually records ground motion throughout the region. Data from this network may be used to assess and locate seismicity, calibrate ground motion simulations, and to conduct seismic early-warning experiments. To assess the response of engineered structures to strong ground motion, seismographs should also be installed at various locations within such engineered structures, e.g., on bridges, overpasses, dams and in tall buildings. The ultimate goal would be to perform 'end-to-end' simulations, starting with the rupture on an earthquake fault, followed by the propagation of the resulting seismic waves from the fault to an engineered structure of interest, and concluding with an assessment of the response of this structure to the imposed ground motion. To facilitate accurate ground motion and end-to-end simulations, one needs to construct a detailed three-dimensional (3D) seismic model of the region of interest. In particular, one needs to assess the slowest shear-wave speeds within the sediments underlying the metropolitan area. Geological information, and, in particular, seismic reaction and refraction surveys are critical in this regard. In the context of end-to-end simulations, detailed numerical models of engineered structures of interest need to be constructed as well. Data recorded by the seismographic network and in engineered structures after small to moderate earthquakes may be used to assess and calibrate the seismic and engineering models based upon numerical simulations. Once the seismic and engineering models produce synthetic ground motion that match the observed ground motion reasonably well, one can perform simulations of hypothetical large earthquakes to assess anticipated strong ground motion and potential damage. Throughout this article we will use the Los Angeles and Taipei metropolitan areas as examples of how to approach quantitative seismic hazard assessment.


2013 ◽  
Vol 8 (5) ◽  
pp. 847-847
Author(s):  
Hiroyuki Fujiwara

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.


2016 ◽  
Vol 59 ◽  
Author(s):  
Maura Murru ◽  
Matteo Taroni ◽  
Aybige Akinci ◽  
Giuseppe Falcone

<p>The recent Amatrice strong event (M<sub>w</sub>6.0) occurred on August 24, 2016 in Central Apennines (Italy) in a seismic gap zone, motivated us to study and provide better understanding of the seismic hazard assessment in the macro area defined as “Central Italy”. The area affected by the sequence is placed between the M<sub>w</sub>6.0 1997 Colfiorito sequence to the north (Umbria-Marche region) the Campotosto area hit by the 2009 L’Aquila sequence M<sub>w</sub>6.3 (Abruzzo region) to the south. The Amatrice earthquake occurred while there was an ongoing effort to update the 2004 seismic hazard map (MPS04) for the Italian territory, requested in 2015 by the Italian Civil Protection Agency to the Center for Seismic Hazard (CPS) of the Istituto Nazionale di Geofisica e Vulcanologia INGV. Therefore, in this study we brought to our attention new earthquake source data and recently developed ground-motion prediction equations (GMPEs). Our aim was to validate whether the seismic hazard assessment in this area has changed with respect to 2004, year in which the MPS04 map was released. In order to understand the impact of the recent earthquakes on the seismic hazard assessment in central Italy we compared the annual seismic rates calculated using a smoothed seismicity approach over two different periods; the Parametric Catalog of the Historical Italian earthquakes (CPTI15) from 1871 to 2003 and the historical and instrumental catalogs from 1871 up to 31 August 2016. Results are presented also in terms of peak ground acceleration (PGA), using the recent ground-motion prediction equations (GMPEs) at Amatrice, interested by the 2016 sequence.</p>


2012 ◽  
Vol 2012 ◽  
pp. 1-10 ◽  
Author(s):  
Zhenming Wang ◽  
David T. Butler ◽  
Edward W. Woolery ◽  
Lanmin Wang

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.


2019 ◽  
Vol 109 (5) ◽  
pp. 2009-2020 ◽  
Author(s):  
Xiurong Xu ◽  
Zhenguo Zhang ◽  
Feng Hu ◽  
Xiaofei Chen

Abstract The Haiyuan fault is a major seismogenic fault on the northeastern edge of the Tibetan–Qinghai plateau. The 16 December 1920 Ms 8.5 Haiyuan, China, earthquake is the largest and most recent event along the eastern Haiyuan fault (the Haiyuan fault in the article). Because only a few near‐field seismic recordings are available, the rupture process remains unclear. To understand the source process and intensity distribution of the 1920 Haiyuan earthquake, we simulated the dynamic rupture and strong ground motion of said earthquake using the 3D curved‐grid finite‐difference method. Considering the differences in epicenter locations among various catalogs, we constructed two models with different source points. For each model, three versions with different fault geometries were investigated: one continuous fault model and two discontinuous fault models with different stepover widths (1.8 and 2.5 km, respectively). A dynamic rupture source model with a final slip distribution similar to that observed on the ground surface was found. The maximum displacement on the ground surface was ∼6.5  m. Based on the dynamic rupture model, we also simulated the strong ground motion and estimated the theoretical intensity distribution. The maximum value of the horizontal peak ground velocity occurs near Haiyuan County, where the intensity reaches XI. Without considering the site conditions, the intensity values in most regions, based on the dynamic scenarios, are smaller than the values from field investigation. In this work, we present physically based insights into the 1920 Haiyuan earthquake, which is important for understanding rupture processes and preventing seismic hazards on the northeastern boundary of the Tibetan plateau.


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