利用爆破事件分析不同速度模型下常规定位方法定位结果

地震定位对速度模型的依赖性很强.四川地区地形复杂,常规工作中可选取多种速度模型进行定位.川西龙门山断裂带为东南部四川盆地和西北部青藏高原东部山区的明显分界线,近年在此断裂带上发生多次较大地震.对发生在该断裂带附近的6个爆破事件和15个天然地震重新定位,并对比结果.研究表明,相同台站包围情况下,川滇3D速度模型稳定性最好,但对浅表爆破不太准确.相比HypoSat(一维速度模型)组合,台站分布对Hypo2000(一维速度模型)和Hypo2000(赵珠速度模型)组合的定位结果影响较大.

Analyzing the positioning results of routine earthquake locationmethods under different velocity models with explosion events data

Earthquake locating depends heavily on velocity model.Because of the complex terrain of Sichuan Province,a variety of speed models can be selected for positioning in routine work.The Longmenshan fault zone is clear dividing line of the southeastern sichuan basin and the eastern mountainous areas of the northwestern Tibetan plateau,and It is along or near this line that most of earthquakes take place in recent years.This paper relocates the six blasting events and 15 natural seismic events in this area,and compares the statistical results.Studies have shown that under the condition of same stations surrounded,the 3-D velocity model of Sichuan-Yunnan is terri fic,but it is not accurate to the shallow blasting.Compared with HypoSat(1-D velocity model),locating results are remarkably affected by the distribution characteristics of the seismic stations in the case of Hypo2000(1-D velocity model)and Hypo2000(Zhao Zhu velocity model).