On the basis of previous study results about the seismic anomaly precursor information quantity, universal and synthetic mathematical expressions that describe the precursor information quantity of various seismic ano...On the basis of previous study results about the seismic anomaly precursor information quantity, universal and synthetic mathematical expressions that describe the precursor information quantity of various seismic anomalies are further given. Starting from large amounts of data of earthquake cases, the problem of the sustained effective time of seismic anomaly was studied again and the mathematical relationship between the sustained effective time of seismic anomaly and continuing effective time of seismic anomaly was further established. About one million pieces of precursor observation data belonging to 371 items of hydrochemistry, deformation, geomagnetism, stress, water level, geoelectricity, etc. In North China region in the period of 1980～ 1997 were collected and sorted out, and the seismic anomaly precursor information quantity of these items was calculated item by item. The evolutionary characteristics of seismic anomaly precursor information field in North China region in about 20 years and their relation to earthquakes were studied; an index system for medium- and short-term predictions of earthquakes with Ms ≥ 5.0 in North China region was established. After having checked by the R-value scoring method, the index system for synthetic earthquake prediction was proved to be of certain efficacy in medium- and short-term earthquake prediction.展开更多
Based on the study of high-precision gravity data obtained from recent studies and the regional gravi- ty network for Yunnan province, a variation in the regional gravity field was identified before the occurrence of ...Based on the study of high-precision gravity data obtained from recent studies and the regional gravi- ty network for Yunnan province, a variation in the regional gravity field was identified before the occurrence of the Yunnan Jinggu M6.6 earthquake.展开更多
By using the integral dynamic adjustment of the "segmentation rate," this paper processes the leveling repetition measurement data of the Dianxi(western Yunnan)area since the 1980s,makes the fitting of the v...By using the integral dynamic adjustment of the "segmentation rate," this paper processes the leveling repetition measurement data of the Dianxi(western Yunnan)area since the 1980s,makes the fitting of the velocity surface for vertical deformation with multi-surface function,and splits information of the vertical deformation field.The dynamic evolution of the deformation field and vertical deformation information norm-shear deformation,extension deformation,volumetric deformation,and quasi acceleration,which are the distribution characteristics of variation,are studied by using the information split before the Lijiang earthquake with MS7.0(February 3,1996)in the north of the Dianxi(western Yunnan)leveling network.The results indicate that in Dianxi(western Yunnan)area,the acute vertical differential movement of the large-scale deformation velocity high gradient belt and high information norm distribution in the Lijiang,Yongsheng,and its adjacent areas in the middle stage of the 1980s is the reflection展开更多
Three methods of extracting the information of anomalies of a precursory group are put forward, i.e., the mathematical analyses of the synthetic information of earthquake precursors (S), the inhomogeneous degree of pr...Three methods of extracting the information of anomalies of a precursory group are put forward, i.e., the mathematical analyses of the synthetic information of earthquake precursors (S), the inhomogeneous degree of precursory groups (ID) and the values of short-term and impending anomaly in near-source area (NS). Using these methods, we calculate the observational data of deformation, underground fluid and hydrochemical constituents obtained from different seismic stations in the Sichuan-Yunnan region and conclude that the synthetic precursory anomalies of a single strong earthquake with M S6.0 differ greatly from those of the grouped strong earthquakes, for the anomalous information of precursory groups are more abundant. The three methods of extracting the synthetic precursory anomaly and the related numerical results can be applied into the practice of prediction to the grouped strong earthquakes in the Sichuan-Yunnan region. Inhomogeneous degree (ID) of synthetic precursory anomaly can be identified automatically because it takes the threshold of distributive characteristics of the anomalies of precursory group as its criterion for anomaly.展开更多
Based on the extraction and calculation of the short-term seismic precursory information magnitude from the 114 major precursory observations in the North China region, and together with consideration of factors such ...Based on the extraction and calculation of the short-term seismic precursory information magnitude from the 114 major precursory observations in the North China region, and together with consideration of factors such as geological structure, seismicity, crustal thickness, and in particular, the current geodynamics of the region, the authors studied the time-space evolution characteristics of the short-term earthquake precursory information magnitude and its relationship with earthquakes and proposed the index and method for the short-term synthetic prediction of earthquakes with M S≥5.0 in the North China region. The inspection through R-value shows that the method is effective to a certain extent for earthquake prediction.展开更多
By systematically analyzing the data of gravity reiteration in the Hexi region and taking a dynamic viewpoint, we have studied the evolution characters of gravity field during the preparation-occurrence of the Jingtai...By systematically analyzing the data of gravity reiteration in the Hexi region and taking a dynamic viewpoint, we have studied the evolution characters of gravity field during the preparation-occurrence of the Jingtai M S5.9 earthquake of June 6, 2000. The patterns of dynamic change of the gravity field clearly reflected how the gravity field evolved from the quasi-homogeneous state to non-homogeneous state for earthquake preparation and then the earthquake occurred. Besides, we have also studied the relation between the characteristic gravity change and strong earthquake activity.展开更多
基金the project of "Ninth Five-year Plan" of China Seismological Bureau (95-04-01-02-02), China.
文摘On the basis of previous study results about the seismic anomaly precursor information quantity, universal and synthetic mathematical expressions that describe the precursor information quantity of various seismic anomalies are further given. Starting from large amounts of data of earthquake cases, the problem of the sustained effective time of seismic anomaly was studied again and the mathematical relationship between the sustained effective time of seismic anomaly and continuing effective time of seismic anomaly was further established. About one million pieces of precursor observation data belonging to 371 items of hydrochemistry, deformation, geomagnetism, stress, water level, geoelectricity, etc. In North China region in the period of 1980～ 1997 were collected and sorted out, and the seismic anomaly precursor information quantity of these items was calculated item by item. The evolutionary characteristics of seismic anomaly precursor information field in North China region in about 20 years and their relation to earthquakes were studied; an index system for medium- and short-term predictions of earthquakes with Ms ≥ 5.0 in North China region was established. After having checked by the R-value scoring method, the index system for synthetic earthquake prediction was proved to be of certain efficacy in medium- and short-term earthquake prediction.
基金supported by the National Natural Science Foundation of China(41304059,41304059)the Seismic Industry Research Project(201308004)
文摘Based on the study of high-precision gravity data obtained from recent studies and the regional gravi- ty network for Yunnan province, a variation in the regional gravity field was identified before the occurrence of the Yunnan Jinggu M6.6 earthquake.
基金This project was sponsored by the "Ninth Five-Year ScienceTechnology Plan" (95-04-04-01-01) of the State Seismological Bureau, China
文摘By using the integral dynamic adjustment of the "segmentation rate," this paper processes the leveling repetition measurement data of the Dianxi(western Yunnan)area since the 1980s,makes the fitting of the velocity surface for vertical deformation with multi-surface function,and splits information of the vertical deformation field.The dynamic evolution of the deformation field and vertical deformation information norm-shear deformation,extension deformation,volumetric deformation,and quasi acceleration,which are the distribution characteristics of variation,are studied by using the information split before the Lijiang earthquake with MS7.0(February 3,1996)in the north of the Dianxi(western Yunnan)leveling network.The results indicate that in Dianxi(western Yunnan)area,the acute vertical differential movement of the large-scale deformation velocity high gradient belt and high information norm distribution in the Lijiang,Yongsheng,and its adjacent areas in the middle stage of the 1980s is the reflection
文摘Three methods of extracting the information of anomalies of a precursory group are put forward, i.e., the mathematical analyses of the synthetic information of earthquake precursors (S), the inhomogeneous degree of precursory groups (ID) and the values of short-term and impending anomaly in near-source area (NS). Using these methods, we calculate the observational data of deformation, underground fluid and hydrochemical constituents obtained from different seismic stations in the Sichuan-Yunnan region and conclude that the synthetic precursory anomalies of a single strong earthquake with M S6.0 differ greatly from those of the grouped strong earthquakes, for the anomalous information of precursory groups are more abundant. The three methods of extracting the synthetic precursory anomaly and the related numerical results can be applied into the practice of prediction to the grouped strong earthquakes in the Sichuan-Yunnan region. Inhomogeneous degree (ID) of synthetic precursory anomaly can be identified automatically because it takes the threshold of distributive characteristics of the anomalies of precursory group as its criterion for anomaly.
文摘Based on the extraction and calculation of the short-term seismic precursory information magnitude from the 114 major precursory observations in the North China region, and together with consideration of factors such as geological structure, seismicity, crustal thickness, and in particular, the current geodynamics of the region, the authors studied the time-space evolution characteristics of the short-term earthquake precursory information magnitude and its relationship with earthquakes and proposed the index and method for the short-term synthetic prediction of earthquakes with M S≥5.0 in the North China region. The inspection through R-value shows that the method is effective to a certain extent for earthquake prediction.
基金theJointSeismologicalScienceFounda tion (10 1118)and"Three in OneCombination"specialfundofChinaSeismologicalBureau
文摘By systematically analyzing the data of gravity reiteration in the Hexi region and taking a dynamic viewpoint, we have studied the evolution characters of gravity field during the preparation-occurrence of the Jingtai M S5.9 earthquake of June 6, 2000. The patterns of dynamic change of the gravity field clearly reflected how the gravity field evolved from the quasi-homogeneous state to non-homogeneous state for earthquake preparation and then the earthquake occurred. Besides, we have also studied the relation between the characteristic gravity change and strong earthquake activity.
