The National Strong-Motion Observation Network System of China has collected over 12 000 strong-motion recordings from 2007 to December 2020.This study assembled the source-related metadata of 1 920 earthquakes associ...The National Strong-Motion Observation Network System of China has collected over 12 000 strong-motion recordings from 2007 to December 2020.This study assembled the source-related metadata of 1 920 earthquakes associated with assembled well-processed recordings of China.The earthquake basic information,focal mechanisms,and the fault geometry were collected from various institutes and literature.We recommended the MWvalues for 900 earthquakes,the fault types for 1 064 earthquakes,and the fault geometries for 18 large earthquakes.We also performed the statistical analysis for establishing the empirical conversions of MW-MS,and ML,and providing the empirical relationships between MWand ruptured area,aspect ratio,respectively.Moreover,the ruptured fault geometries of large earthquakes were used to preliminarily divide all earthquakes considered into 1 141 mainshocks,and 779 aftershocks.The finite-fault distances(RJBand Rrup) of strong-motion recordings from the 18 large earthquakes were calculated,and then used to yield the statistic relationships between the point-source distances(Repiand Rhyp) and finite-fault distances.We finally provided the earthquake source database freely accessible at website.The source-related metadata can be directly applied to develop the ground motion prediction equations of China.展开更多
In this paper we study existence of solutions of a class of Cauchy problems for porous medium equations with strongly nonlinear sources or absorptions and convections when the initial trace is a Radon measure μ on RN.
In this paper,approaches are developed to delineate the potential seismic source regions of moderately strong earthquakes that do not have clear seismotectonic settings.Based on comprehensive analysis of regional tect...In this paper,approaches are developed to delineate the potential seismic source regions of moderately strong earthquakes that do not have clear seismotectonic settings.Based on comprehensive analysis of regional tectonic backgrounds and seismicity,the data,such as isoseisrnals,spatial distribution of after shocks,regional tectonic stress field,and focal mechanisms,are employed for the delineation of the potential seismic source regions.The reliability of such potential seismic source regions is also discussed.展开更多
The characteristics of harmless treatment of hazardous waste are analyzed. Then study how to determine the strong source leakage landfill and conduct environmental risk assessment. Finally discuss the methods to stren...The characteristics of harmless treatment of hazardous waste are analyzed. Then study how to determine the strong source leakage landfill and conduct environmental risk assessment. Finally discuss the methods to strengthen the management and treatment of landfill. It is hoped that the research can help landfills to determine appropriate management methods and reduce the environmental risks of hazardous waste landfills.展开更多
This paper briefly reviews the characteristics and major processes of the explicit finite element method in modeling the near-fault ground motion field. The emphasis is on the finite element-related problems in the fi...This paper briefly reviews the characteristics and major processes of the explicit finite element method in modeling the near-fault ground motion field. The emphasis is on the finite element-related problems in the finite fault source modeling. A modified kinematic source model is presented, in which vibration with some high frequency components is introduced into the traditional slip time function to ensure that the source and ground motion include sufficient high frequency components. The model presented is verified through a simple modeling example. It is shown that the predicted near-fault ground motion field exhibits similar characteristics to those observed in strong motion records, such as the hanging wall effect, vertical effect, fling step effect and velocity pulse effect, etc.展开更多
The strong noise produced by the leakage of electricity from marine seismic streamers is often received with seismic signals during marine seismic exploration. Traditional denoising methods show unsatisfactory effects...The strong noise produced by the leakage of electricity from marine seismic streamers is often received with seismic signals during marine seismic exploration. Traditional denoising methods show unsatisfactory effects when eliminating strong noise of this kind. Assuming that the strong noise signals have the same statistical properties, a blind source separation （BSS） algorithm is proposed in this paper that results in a new denoising algorithm based on the constrained multi-user kurtosis （MUK） optimization criterion. This method can separate strong noise that shares the same statistical properties as the seismic data records and then eliminate them. Theoretical and field data processing all show that the denoising algorithm, based on multi-user kurtosis optimization criterion, is valid for eliminating the strong noise which is produced by the leakage of electricity from the marine seismic streamer so as to preserve more effective signals and increase the signal-noise ratio. This method is feasible and widely applicable.展开更多
A random synthesis procedure based on finite fault model is adopted for near field strong ground motion simulation in this paper. The fault plane of the source is divided into a number of sub-sources, the whole moment...A random synthesis procedure based on finite fault model is adopted for near field strong ground motion simulation in this paper. The fault plane of the source is divided into a number of sub-sources, the whole moment magnitude is also divided into more sub-events. The Fourier spectrum of ground motion caused by a sub-event in given sub-source, then can be derived by means of taking the point source spectrum, attenuation with distance, energy dissipation, and near surface effect, into account. A time history is synthesized from this amplitude spectrum and a random phase spectrum, and being combined with an envelope function. The ground motion is worked out by superposition of all time histories from each sub-event in each sub-source, with time lags determining by the differences between the triggering times of sub-events and distances of the sub-sources. From the example of simulations at 21 near field points in a scenario earthquake with 4 dip angles of the fault plane, it is illustrated that the procedure can describe the rupture directivity and hanging wall effect very well. To validate the procedure, the response spectra and time histories recorded at three near fault stations MCN, LV3 and PCD during the Northridge earthquake in 1994, are compared with the simulated ones.展开更多
A method to predict near-field strong ground motions for scenario earthquakes on active faults is proposed. First, macro-source parameters characterizing the entire source area, i.e., global source parameters, includi...A method to predict near-field strong ground motions for scenario earthquakes on active faults is proposed. First, macro-source parameters characterizing the entire source area, i.e., global source parameters, including fault length, fault width, rupture area, average slip on the fault plane, etc., are estimated by seismogeology survey, seismicity and seismic scaling laws. Second, slip distributions characterizing heterogeneity or roughness on the fault plane, i.e., local source parameters, are reproduced/evaluated by the hybrid slip model. Finally, the finite fault source model, developed from both the global and local source parameters, is combined with the stochastically synthetic technique of ground motion using the dynamic comer frequency based on seismology. The proposed method is applied to simulate the acceleration time histories on three base-rock stations during the 1994 Northridge earthquake. Comparisons between the predicted and recorded acceleration time histories show that the method is feasible and practicable.展开更多
Nobel Prize Committee:One month ago,we wrote the letter to Nobel Prize Committee reminding you that LIGO did not find gravitational waves.We provided strong proofs to reveal the falsity and fraudulence of LIGO’s expe...Nobel Prize Committee:One month ago,we wrote the letter to Nobel Prize Committee reminding you that LIGO did not find gravitational waves.We provided strong proofs to reveal the falsity and fraudulence of LIGO’s experiments.However,three days ago,LIGO and Virgo jointly announced the fourth detections of gravitational waves named GW 20170814 with 10 time’s accuracy to locate the source of wave.Obviously,they want to win the Nobel physics Prize in 2017.Several days ago,we read the paper of professors Hao Liu and Danish’s team in the University of Nottingham,published in《Cosmology and Astroparticle Physics》2017,Auvip[1].Our judgment was proved again.In the paper,more and stronger proofs were raised to show the falsity and fraudulence of LIGO’s experiments.展开更多
On the basis of previous study of the 1679 Sanhe-Pinggu(M8.0) earthquake,the biggest event in history ever recorded in Beijing and its adjacent area,we made a 3-D strong ground motion simulation utilizing the staggere...On the basis of previous study of the 1679 Sanhe-Pinggu(M8.0) earthquake,the biggest event in history ever recorded in Beijing and its adjacent area,we made a 3-D strong ground motion simulation utilizing the staggered-grid finite differences method to study the distributions of peak ground velocity with different earthquake source models in the Beijing region.In the paper,earthquake source models and a transmission medium velocity model are established and the corresponding parameters are given in accordance to the results from a related previous study.Then,using a three-dimensional finite difference computing program of near-fault strong ground motion developed by Graves,the peak ground velocity caused by a destructive earthquake in the Beijing area is simulated.In our computation model,the earthquake source is 3km in depth,and a total number of 21,679 observation points on the ground surface are figured out.The transmission medium velocity model is composed of four stratums which are the Quaternary deposit,the upper crust,the upper part of the middle crust and the lower part of the middle crust.With the minimum grid spacing of 0.15km,a total of 2.28×106 grids are generated.Using a time step of 0.02 seconds we calculated the peak ground velocity for a duration of 8 seconds.After the analysis of the simulation results,we observed some basic characteristics of near-fault strong ground motion such as the concentration effect of near-fault peak ground velocity,rupture directivity effect,hanging wall effect,and basin effect.The results from our simulation and analysis suggest that the source and transmitting medium parameters in our model are suitable and the finite difference method is applicable to estimate the distribution of strong ground motion in the study region.展开更多
We study the solvability of the Cauchy problem （1.1）-（1.2） for the largest possible class of initial values,for which （1.1）-（1.2） has a local solution.Moreover,we also study the critical case related to the in...We study the solvability of the Cauchy problem （1.1）-（1.2） for the largest possible class of initial values,for which （1.1）-（1.2） has a local solution.Moreover,we also study the critical case related to the initial value u<sub>0</sub>,for 1【p【∞.展开更多
基金supported by the National Key R&D Program of China(Grant No.2019YFE0115700).
文摘The National Strong-Motion Observation Network System of China has collected over 12 000 strong-motion recordings from 2007 to December 2020.This study assembled the source-related metadata of 1 920 earthquakes associated with assembled well-processed recordings of China.The earthquake basic information,focal mechanisms,and the fault geometry were collected from various institutes and literature.We recommended the MWvalues for 900 earthquakes,the fault types for 1 064 earthquakes,and the fault geometries for 18 large earthquakes.We also performed the statistical analysis for establishing the empirical conversions of MW-MS,and ML,and providing the empirical relationships between MWand ruptured area,aspect ratio,respectively.Moreover,the ruptured fault geometries of large earthquakes were used to preliminarily divide all earthquakes considered into 1 141 mainshocks,and 779 aftershocks.The finite-fault distances(RJBand Rrup) of strong-motion recordings from the 18 large earthquakes were calculated,and then used to yield the statistic relationships between the point-source distances(Repiand Rhyp) and finite-fault distances.We finally provided the earthquake source database freely accessible at website.The source-related metadata can be directly applied to develop the ground motion prediction equations of China.
文摘In this paper we study existence of solutions of a class of Cauchy problems for porous medium equations with strongly nonlinear sources or absorptions and convections when the initial trace is a Radon measure μ on RN.
文摘In this paper,approaches are developed to delineate the potential seismic source regions of moderately strong earthquakes that do not have clear seismotectonic settings.Based on comprehensive analysis of regional tectonic backgrounds and seismicity,the data,such as isoseisrnals,spatial distribution of after shocks,regional tectonic stress field,and focal mechanisms,are employed for the delineation of the potential seismic source regions.The reliability of such potential seismic source regions is also discussed.
文摘The characteristics of harmless treatment of hazardous waste are analyzed. Then study how to determine the strong source leakage landfill and conduct environmental risk assessment. Finally discuss the methods to strengthen the management and treatment of landfill. It is hoped that the research can help landfills to determine appropriate management methods and reduce the environmental risks of hazardous waste landfills.
文摘This paper briefly reviews the characteristics and major processes of the explicit finite element method in modeling the near-fault ground motion field. The emphasis is on the finite element-related problems in the finite fault source modeling. A modified kinematic source model is presented, in which vibration with some high frequency components is introduced into the traditional slip time function to ensure that the source and ground motion include sufficient high frequency components. The model presented is verified through a simple modeling example. It is shown that the predicted near-fault ground motion field exhibits similar characteristics to those observed in strong motion records, such as the hanging wall effect, vertical effect, fling step effect and velocity pulse effect, etc.
基金supported by the National Natural Science Foundation of China(No. 41176077)the State Oceanic Administration Young Marine Science Foundation(No. 2013702)
文摘The strong noise produced by the leakage of electricity from marine seismic streamers is often received with seismic signals during marine seismic exploration. Traditional denoising methods show unsatisfactory effects when eliminating strong noise of this kind. Assuming that the strong noise signals have the same statistical properties, a blind source separation （BSS） algorithm is proposed in this paper that results in a new denoising algorithm based on the constrained multi-user kurtosis （MUK） optimization criterion. This method can separate strong noise that shares the same statistical properties as the seismic data records and then eliminate them. Theoretical and field data processing all show that the denoising algorithm, based on multi-user kurtosis optimization criterion, is valid for eliminating the strong noise which is produced by the leakage of electricity from the marine seismic streamer so as to preserve more effective signals and increase the signal-noise ratio. This method is feasible and widely applicable.
基金Earthquake Science Foundation under Contract No.201009
文摘A random synthesis procedure based on finite fault model is adopted for near field strong ground motion simulation in this paper. The fault plane of the source is divided into a number of sub-sources, the whole moment magnitude is also divided into more sub-events. The Fourier spectrum of ground motion caused by a sub-event in given sub-source, then can be derived by means of taking the point source spectrum, attenuation with distance, energy dissipation, and near surface effect, into account. A time history is synthesized from this amplitude spectrum and a random phase spectrum, and being combined with an envelope function. The ground motion is worked out by superposition of all time histories from each sub-event in each sub-source, with time lags determining by the differences between the triggering times of sub-events and distances of the sub-sources. From the example of simulations at 21 near field points in a scenario earthquake with 4 dip angles of the fault plane, it is illustrated that the procedure can describe the rupture directivity and hanging wall effect very well. To validate the procedure, the response spectra and time histories recorded at three near fault stations MCN, LV3 and PCD during the Northridge earthquake in 1994, are compared with the simulated ones.
基金China Postdoctoral Science Foundation UnderGrant No. 2005037650 Heilongjiang Province PostdoctoralScience Foundation China EarthquakeAdministration’s Tenth"Five Year Plans" Project
文摘A method to predict near-field strong ground motions for scenario earthquakes on active faults is proposed. First, macro-source parameters characterizing the entire source area, i.e., global source parameters, including fault length, fault width, rupture area, average slip on the fault plane, etc., are estimated by seismogeology survey, seismicity and seismic scaling laws. Second, slip distributions characterizing heterogeneity or roughness on the fault plane, i.e., local source parameters, are reproduced/evaluated by the hybrid slip model. Finally, the finite fault source model, developed from both the global and local source parameters, is combined with the stochastically synthetic technique of ground motion using the dynamic comer frequency based on seismology. The proposed method is applied to simulate the acceleration time histories on three base-rock stations during the 1994 Northridge earthquake. Comparisons between the predicted and recorded acceleration time histories show that the method is feasible and practicable.
文摘Nobel Prize Committee:One month ago,we wrote the letter to Nobel Prize Committee reminding you that LIGO did not find gravitational waves.We provided strong proofs to reveal the falsity and fraudulence of LIGO’s experiments.However,three days ago,LIGO and Virgo jointly announced the fourth detections of gravitational waves named GW 20170814 with 10 time’s accuracy to locate the source of wave.Obviously,they want to win the Nobel physics Prize in 2017.Several days ago,we read the paper of professors Hao Liu and Danish’s team in the University of Nottingham,published in《Cosmology and Astroparticle Physics》2017,Auvip[1].Our judgment was proved again.In the paper,more and stronger proofs were raised to show the falsity and fraudulence of LIGO’s experiments.
基金This project was sponsored by the National Development and Reform Commission,PRC(20041138)
文摘On the basis of previous study of the 1679 Sanhe-Pinggu(M8.0) earthquake,the biggest event in history ever recorded in Beijing and its adjacent area,we made a 3-D strong ground motion simulation utilizing the staggered-grid finite differences method to study the distributions of peak ground velocity with different earthquake source models in the Beijing region.In the paper,earthquake source models and a transmission medium velocity model are established and the corresponding parameters are given in accordance to the results from a related previous study.Then,using a three-dimensional finite difference computing program of near-fault strong ground motion developed by Graves,the peak ground velocity caused by a destructive earthquake in the Beijing area is simulated.In our computation model,the earthquake source is 3km in depth,and a total number of 21,679 observation points on the ground surface are figured out.The transmission medium velocity model is composed of four stratums which are the Quaternary deposit,the upper crust,the upper part of the middle crust and the lower part of the middle crust.With the minimum grid spacing of 0.15km,a total of 2.28×106 grids are generated.Using a time step of 0.02 seconds we calculated the peak ground velocity for a duration of 8 seconds.After the analysis of the simulation results,we observed some basic characteristics of near-fault strong ground motion such as the concentration effect of near-fault peak ground velocity,rupture directivity effect,hanging wall effect,and basin effect.The results from our simulation and analysis suggest that the source and transmitting medium parameters in our model are suitable and the finite difference method is applicable to estimate the distribution of strong ground motion in the study region.
基金Project supported by the National Natural Science Foundation of China (19971070)
文摘We study the solvability of the Cauchy problem （1.1）-（1.2） for the largest possible class of initial values,for which （1.1）-（1.2） has a local solution.Moreover,we also study the critical case related to the initial value u<sub>0</sub>,for 1【p【∞.
