Based on the results of focal mechanism solutions in southeastern areas of China （south of 34°N and east of 105° E）, this article analyzes the correlation of focal mechanism solutions with seismogenic stru...Based on the results of focal mechanism solutions in southeastern areas of China （south of 34°N and east of 105° E）, this article analyzes the correlation of focal mechanism solutions with seismogenic structures of moderate strong earthquakes and the direction of potential source zones. The data show that the nodal planes of focal mechanism solutions and the principle stresses in southern China are of predominantly similar directions, most of the solutions for M ≥4.0 earthquakes correspond to the main structure directions as well as the directions of potential source zones. The statistical results of multiple small earthquakes concerning nodal planes and main stress axes are also reliable for determining the direction of potential source zones. According to the analysis of focal mechanism solutions, long-axis direction of isoseismals distribution of aftershocks, geologic structures, and seismic activity in two areas of the Ms6.1 earthquake in the south Yellow Sea in 1996 and the MsS.2 earthquake in Fujian in 1997, the potential source zone division is discussed.展开更多
In this paper we discuss the differences and relationship between"great earthquakes",rare ground motion,and very rare ground motion.Taking the Beichuan-Yingxiu potential seismic source zone in Longmenshan se...In this paper we discuss the differences and relationship between"great earthquakes",rare ground motion,and very rare ground motion.Taking the Beichuan-Yingxiu potential seismic source zone in Longmenshan seismic belt as an example,we revealed the relationship between the effects of"great earthquakes"and rare ground and very rare ground motion.After pointing out scientific and technical problems in the current seismic fortification system,we suggest that very rare ground motion should be considered if we want to deduce the potential hazard of great earthquakes in the future.展开更多
The principle of three-level delineation is adopted in determination of a potential seismic source for the new National Seismic Ground Motion Parameters Zoning Map of China,to embody the inhomogeneity of the spatial d...The principle of three-level delineation is adopted in determination of a potential seismic source for the new National Seismic Ground Motion Parameters Zoning Map of China,to embody the inhomogeneity of the spatial distribution of background seismic activity and induct a uniform seismotectonic model for each seismotectonic region. Based on achievements of determining potential seismic sources in southwestern China,this paper introduces the basic characteristics, historical earthquakes magnitude and frequency distribution,identification of deformation mechanism of main active tectonic structures for the Longmenshan and Chengdu seismotectonic region in the Longmenshan seismic region,establishes the seismogenic model for each seismotectonic region,and identifies the upper limit of background earthquakes. A simple method is also put forward for calculating the spatial distribution function of a background seismic source.展开更多
基金The research was supported by the key project entitled"Seismic Safety Evaluation and Seismic Structure Study"under the 10th Five-Year Plan of China EarthquakeAdministration
文摘Based on the results of focal mechanism solutions in southeastern areas of China （south of 34°N and east of 105° E）, this article analyzes the correlation of focal mechanism solutions with seismogenic structures of moderate strong earthquakes and the direction of potential source zones. The data show that the nodal planes of focal mechanism solutions and the principle stresses in southern China are of predominantly similar directions, most of the solutions for M ≥4.0 earthquakes correspond to the main structure directions as well as the directions of potential source zones. The statistical results of multiple small earthquakes concerning nodal planes and main stress axes are also reliable for determining the direction of potential source zones. According to the analysis of focal mechanism solutions, long-axis direction of isoseismals distribution of aftershocks, geologic structures, and seismic activity in two areas of the Ms6.1 earthquake in the south Yellow Sea in 1996 and the MsS.2 earthquake in Fujian in 1997, the potential source zone division is discussed.
基金funded by Special Project of Scientific Research in the Field of Earthquake Science,China Earthquake Administration(201308018 and 201108002)
文摘In this paper we discuss the differences and relationship between"great earthquakes",rare ground motion,and very rare ground motion.Taking the Beichuan-Yingxiu potential seismic source zone in Longmenshan seismic belt as an example,we revealed the relationship between the effects of"great earthquakes"and rare ground and very rare ground motion.After pointing out scientific and technical problems in the current seismic fortification system,we suggest that very rare ground motion should be considered if we want to deduce the potential hazard of great earthquakes in the future.
基金sponsored by the Study on the Determination of the Seismicity Parameters of Background Source-A Case Study of the Longmenshan Seismic Statistical Zone,Earthquake Administration of Sichuan Province
文摘The principle of three-level delineation is adopted in determination of a potential seismic source for the new National Seismic Ground Motion Parameters Zoning Map of China,to embody the inhomogeneity of the spatial distribution of background seismic activity and induct a uniform seismotectonic model for each seismotectonic region. Based on achievements of determining potential seismic sources in southwestern China,this paper introduces the basic characteristics, historical earthquakes magnitude and frequency distribution,identification of deformation mechanism of main active tectonic structures for the Longmenshan and Chengdu seismotectonic region in the Longmenshan seismic region,establishes the seismogenic model for each seismotectonic region,and identifies the upper limit of background earthquakes. A simple method is also put forward for calculating the spatial distribution function of a background seismic source.
