We conducted rapid inversions of rupture process for the 2023 earthquake doublet occurred in SE Türkiye,the first with a magnitude of M_(W)7.8 and the second with a magnitude of M_(W)7.6,using teleseismic and str...We conducted rapid inversions of rupture process for the 2023 earthquake doublet occurred in SE Türkiye,the first with a magnitude of M_(W)7.8 and the second with a magnitude of M_(W)7.6,using teleseismic and strong-motion data.The teleseismic rupture models of the both events were obtained approximately 88 and 55 minutes after their occurrences,respectively.The rupture models indicated that the first event was an asymmetric bilateral event with ruptures mainly propagating to the northeast,while the second one was a unilateral event with ruptures propagating to the west.This information could be useful in locating the meizoseismal areas.Compared with teleseismic models,the strong-motion models showed relatively higher resolution.A noticeable difference was found for the M_(W)7.6 earthquake,for which the strong-motion models shows a bilateral event,rather than a unilateral event,but the dominant rupture direction is still westward.Nevertheless,all strong-motion models are consistent with the teleseismic models in terms of magnitudes,durations,and dominant rupture directions.This suggests that both teleseismic and strong-motion data can be used for fast determination of major source characteristics.In contrast,the strong-motion data would be preferable in future emergency responses since they are recorded earlier and have a better resolution ability on the source ruptures.展开更多
Ground motions are significantly influenced by dynamic characteristics of overburden soil layers near ground surface,as thick and soft soil layers would obviously amplify the ground motion strength. The conventional r...Ground motions are significantly influenced by dynamic characteristics of overburden soil layers near ground surface,as thick and soft soil layers would obviously amplify the ground motion strength. The conventional research method on soil nonlinear dynamic characteristics under strong motions is based on experiments in laboratories for the deficiency of observation data,but it is difficult to reliably simulate the complex factors of soils in actual earthquake durations,including loading paths,boundary conditions,and drainage conditions. The incremental data of the vertical downhole observation array,which is comprised of at least one observation point on ground surface and one observation point in a downhole rock base, makes it possible to study soil nonlinear dynamics according to in situ observation data,and provides new basic data and development opportunities to soil nonlinear dynamics studies.展开更多
Regionalized location accuracy of the China National Seismograph Network was estimated using the results obtained by studying “repeating earthquakes" or “doublets" in and around China by Schaff and Richard...Regionalized location accuracy of the China National Seismograph Network was estimated using the results obtained by studying “repeating earthquakes" or “doublets" in and around China by Schaff and Richards (2004). It is assumed that the “repeating events" or “doublets" are separated by no more than 1km, and the network measured apparent distance X of “doublets" indicates the order of magnitudes of the location error. It is observed that the average location accuracy of the China National Seismograph Network, as represented by average X value, is in the order of magnitudes of 10km, and is larger in the Qinghai-Xizang (Tibet) Plateau, western and northern Xinjiang, and eastern Inner Mongolia.展开更多
We introduce in this paper a method to calculate response spectra of earthquake ground motion from seismograms of Type 513 seismograph. The seismograms of two horizontal components of the M s 7.1 earthquake, an a...We introduce in this paper a method to calculate response spectra of earthquake ground motion from seismograms of Type 513 seismograph. The seismograms of two horizontal components of the M s 7.1 earthquake, an aftershock of 1976 M S=7.8 Tangshan earthquake, recorded by type 513 seismograph in Taian station are used as an example. After curve digitization, arc shape curve correction, equal distance interpolation and instrument response correction, the absolute acceleration response spectra, relative velocity response spectra and relative displacement response spectra of different damping ratios in the period range of T ≤10 s are calculated in frequency domain.展开更多
According to different testing purposes, methods and available environmental conditions, the seismograph testing can be divided into laboratory and on-site testing, respectively. The testing of the seismograph's k...According to different testing purposes, methods and available environmental conditions, the seismograph testing can be divided into laboratory and on-site testing, respectively. The testing of the seismograph's key parameters and other concerning technical specifications are well described in guide documents(China Earthquake Administration, 2017). This includes seismometer sensitivity, linearity and clip levels based on the shake table test, as well as the seismometer natural period, damping constant based on electrical calibration(Wang Guangfu,1986; Ple?inger A.,1993) and instrumental self-noise collocation estimation(Holcomb L.G., 1989; Sleeman R. et al., 2006). However, with the development of seismic observation technology, many new requirements for the performance evaluation of seismographs have been put forward, and new testing items and methods have emerged.展开更多
In order to eliminate chaotic oscillation of electromechanical characteristics of seismograph system, the complex dynamic the four-dimensional nonlinear equations of seismograph system were analyzed. Sliding mode meth...In order to eliminate chaotic oscillation of electromechanical characteristics of seismograph system, the complex dynamic the four-dimensional nonlinear equations of seismograph system were analyzed. Sliding mode method was applied to stabilize the chaotic orbits of the eleetromechanieal seismograph system to arbitrary chosen fixed points and periodic orbits precisely, and MATLAB simulations were presented to confirm the validity of the controller. The results show that using sliding mode method can make the system track target orbit strictly and smoothly with short transition time, and its insensitivity to noise disturbances is shown. It also provides reference for relevant chaos control in relevant system.展开更多
The authors proposed a method for obtaining high-quality acceleration seismograms from velocity type seismograms of digital Seismographic network, and took as an example the analysis and processing of the seismograms ...The authors proposed a method for obtaining high-quality acceleration seismograms from velocity type seismograms of digital Seismographic network, and took as an example the analysis and processing of the seismograms of a same earthquake that was simultaneously recorded by velocity seismograph CTS1-EDAS24 and strong motion seismograph EST-Q4128 installed in Jixian Station, Tianjin. The calculation steps and the processing method have been discussed in detail. From the analysis and the comparison of the obtained results, it is concluded that the proposed method is simple and effective, and it broadens the application of digital seismographic network.展开更多
Criminal law involves crucial rights of the public,including property rights,political rights,freedom,and even life.As a result,on the one hand,any change to the rule by criminal law may have a significant impact on p...Criminal law involves crucial rights of the public,including property rights,political rights,freedom,and even life.As a result,on the one hand,any change to the rule by criminal law may have a significant impact on people’s lives;on the other hand,any change to the rule by criminal law is a highly sensitive issue.In view of these points,the rule by criminal law is often referred to as the seismograph for the protection of human rights,indicating the utmost importance of rule by criminal law展开更多
The purpose of this research was to suggest an applicable procedure for computing the centroid moment tensor(CMT)automatically and in real time from earthquakes that occur in Indonesia and the surrounding areas.Gisola...The purpose of this research was to suggest an applicable procedure for computing the centroid moment tensor(CMT)automatically and in real time from earthquakes that occur in Indonesia and the surrounding areas.Gisola software was used to estimate the CMT solution by selecting the velocity model that best suited the local and regional geological conditions in Indonesia and the surrounding areas.The data used in this study were earthquakes with magnitudes of 5.4 to 8.0.High-quality,real-time broadband seismographic data were provided by the International Federation of Digital Seismograph Networks Web Services(FDSNWS)and the European Integrated Data Archive(EIDA)Federation in Indonesia and the surrounding areas.Furthermore,the inversion process and filter adjustment were carried out on the seismographic data to obtain good CMT solutions.The CMT solutions from Gisola provided good-quality solutions,in which all earthquake data had A-level quality(high quality,with good variant reduction).The Gisola CMT solution was justified with the Global CMT(GCMT)solution by using the Kagan angle value,with an average of approximately 11.2°.This result suggested that the CMT solution generated from Gisola was trustworthy and reliable.The Gisola CMT solution was typically available within approximately 15 minutes after an earthquake occurred.Once it met the quality requirement,it was automatically published on the internet.The catalog of local and regional earthquake records obtained through this technology holds great promise for improving the current understanding of regional seismic activity and ongoing tectonic processes.The accurate and real-time CMT solution generated by implementing the Gisola algorithm consisted of moment tensors and moment magnitudes,which provided invaluable insights into earthquakes occurring in Indonesia and the surrounding areas.展开更多
基金supported by the National Key Research and Development Program of China(2022YFF0800603).
文摘We conducted rapid inversions of rupture process for the 2023 earthquake doublet occurred in SE Türkiye,the first with a magnitude of M_(W)7.8 and the second with a magnitude of M_(W)7.6,using teleseismic and strong-motion data.The teleseismic rupture models of the both events were obtained approximately 88 and 55 minutes after their occurrences,respectively.The rupture models indicated that the first event was an asymmetric bilateral event with ruptures mainly propagating to the northeast,while the second one was a unilateral event with ruptures propagating to the west.This information could be useful in locating the meizoseismal areas.Compared with teleseismic models,the strong-motion models showed relatively higher resolution.A noticeable difference was found for the M_(W)7.6 earthquake,for which the strong-motion models shows a bilateral event,rather than a unilateral event,but the dominant rupture direction is still westward.Nevertheless,all strong-motion models are consistent with the teleseismic models in terms of magnitudes,durations,and dominant rupture directions.This suggests that both teleseismic and strong-motion data can be used for fast determination of major source characteristics.In contrast,the strong-motion data would be preferable in future emergency responses since they are recorded earlier and have a better resolution ability on the source ruptures.
基金funded by the Special Research Fund for Seismology(201408020)the Natural Science Foundation of China (51578514,U1434210)
文摘Ground motions are significantly influenced by dynamic characteristics of overburden soil layers near ground surface,as thick and soft soil layers would obviously amplify the ground motion strength. The conventional research method on soil nonlinear dynamic characteristics under strong motions is based on experiments in laboratories for the deficiency of observation data,but it is difficult to reliably simulate the complex factors of soils in actual earthquake durations,including loading paths,boundary conditions,and drainage conditions. The incremental data of the vertical downhole observation array,which is comprised of at least one observation point on ground surface and one observation point in a downhole rock base, makes it possible to study soil nonlinear dynamics according to in situ observation data,and provides new basic data and development opportunities to soil nonlinear dynamics studies.
文摘Regionalized location accuracy of the China National Seismograph Network was estimated using the results obtained by studying “repeating earthquakes" or “doublets" in and around China by Schaff and Richards (2004). It is assumed that the “repeating events" or “doublets" are separated by no more than 1km, and the network measured apparent distance X of “doublets" indicates the order of magnitudes of the location error. It is observed that the average location accuracy of the China National Seismograph Network, as represented by average X value, is in the order of magnitudes of 10km, and is larger in the Qinghai-Xizang (Tibet) Plateau, western and northern Xinjiang, and eastern Inner Mongolia.
文摘We introduce in this paper a method to calculate response spectra of earthquake ground motion from seismograms of Type 513 seismograph. The seismograms of two horizontal components of the M s 7.1 earthquake, an aftershock of 1976 M S=7.8 Tangshan earthquake, recorded by type 513 seismograph in Taian station are used as an example. After curve digitization, arc shape curve correction, equal distance interpolation and instrument response correction, the absolute acceleration response spectra, relative velocity response spectra and relative displacement response spectra of different damping ratios in the period range of T ≤10 s are calculated in frequency domain.
基金sponsored by the Department of Earthquake Monitoring and Prediction,China Earthquake Administration
文摘According to different testing purposes, methods and available environmental conditions, the seismograph testing can be divided into laboratory and on-site testing, respectively. The testing of the seismograph's key parameters and other concerning technical specifications are well described in guide documents(China Earthquake Administration, 2017). This includes seismometer sensitivity, linearity and clip levels based on the shake table test, as well as the seismometer natural period, damping constant based on electrical calibration(Wang Guangfu,1986; Ple?inger A.,1993) and instrumental self-noise collocation estimation(Holcomb L.G., 1989; Sleeman R. et al., 2006). However, with the development of seismic observation technology, many new requirements for the performance evaluation of seismographs have been put forward, and new testing items and methods have emerged.
基金the Independent Research Project of State Key Laboratory of Power Transmission Equipment & System Security and New Technology,China ( No. 2007DA10512711205)
文摘In order to eliminate chaotic oscillation of electromechanical characteristics of seismograph system, the complex dynamic the four-dimensional nonlinear equations of seismograph system were analyzed. Sliding mode method was applied to stabilize the chaotic orbits of the eleetromechanieal seismograph system to arbitrary chosen fixed points and periodic orbits precisely, and MATLAB simulations were presented to confirm the validity of the controller. The results show that using sliding mode method can make the system track target orbit strictly and smoothly with short transition time, and its insensitivity to noise disturbances is shown. It also provides reference for relevant chaos control in relevant system.
文摘The authors proposed a method for obtaining high-quality acceleration seismograms from velocity type seismograms of digital Seismographic network, and took as an example the analysis and processing of the seismograms of a same earthquake that was simultaneously recorded by velocity seismograph CTS1-EDAS24 and strong motion seismograph EST-Q4128 installed in Jixian Station, Tianjin. The calculation steps and the processing method have been discussed in detail. From the analysis and the comparison of the obtained results, it is concluded that the proposed method is simple and effective, and it broadens the application of digital seismographic network.
文摘Criminal law involves crucial rights of the public,including property rights,political rights,freedom,and even life.As a result,on the one hand,any change to the rule by criminal law may have a significant impact on people’s lives;on the other hand,any change to the rule by criminal law is a highly sensitive issue.In view of these points,the rule by criminal law is often referred to as the seismograph for the protection of human rights,indicating the utmost importance of rule by criminal law
基金Universitas Negeri Surabaya,Universitas Sebelas Maret,and Universitas Syiah Kuala for providing research grants for the Indonesian Collaborative Research(RKI)scheme。
文摘The purpose of this research was to suggest an applicable procedure for computing the centroid moment tensor(CMT)automatically and in real time from earthquakes that occur in Indonesia and the surrounding areas.Gisola software was used to estimate the CMT solution by selecting the velocity model that best suited the local and regional geological conditions in Indonesia and the surrounding areas.The data used in this study were earthquakes with magnitudes of 5.4 to 8.0.High-quality,real-time broadband seismographic data were provided by the International Federation of Digital Seismograph Networks Web Services(FDSNWS)and the European Integrated Data Archive(EIDA)Federation in Indonesia and the surrounding areas.Furthermore,the inversion process and filter adjustment were carried out on the seismographic data to obtain good CMT solutions.The CMT solutions from Gisola provided good-quality solutions,in which all earthquake data had A-level quality(high quality,with good variant reduction).The Gisola CMT solution was justified with the Global CMT(GCMT)solution by using the Kagan angle value,with an average of approximately 11.2°.This result suggested that the CMT solution generated from Gisola was trustworthy and reliable.The Gisola CMT solution was typically available within approximately 15 minutes after an earthquake occurred.Once it met the quality requirement,it was automatically published on the internet.The catalog of local and regional earthquake records obtained through this technology holds great promise for improving the current understanding of regional seismic activity and ongoing tectonic processes.The accurate and real-time CMT solution generated by implementing the Gisola algorithm consisted of moment tensors and moment magnitudes,which provided invaluable insights into earthquakes occurring in Indonesia and the surrounding areas.
