论文部分内容阅读
在使用1965——1981年期间的云南区域地震台网记录资料测定地震基本时空参数时,对云南地区及滇川交界处的1600多个震中精度为Ⅰ、Ⅱ类的地震,采用石川法、和达法或高桥法测定了震源深度和虚波速度。本文对这些资料使用统计分析方法,对它们的平面分布特征,及7条深度分布剖面进行了初步探讨。 现有资料发明,云南地区绝大多数地震的震源深度小于30公里。大致以龙陵—瑞丽断裂和永胜—管河断裂为界,以东的云南大部分地区震源深度—般都小于30公里,以西的滇西北地区存在一个北东向的震源深度较深的分布条带。全省范围内,震源深度的变化呈现出由东南向四北逐渐由浅变深的明显趋势;在剑川、鹤庆、丽江、宁蒗—带变化幅度最大。这个趋势与地壳厚度的变化趋势相吻合。虚波速度的分布与震源深度的分布特征基本相似,一般说来,震源深度较深的地方,虚波速度亦较大。
When using the recorded data of Yunnan regional seismograph during 1965-1981 to determine the seismic basic time-space parameters, Ishikawa’s method was applied to more than 1,600 epicenter earthquakes with epicenters of type I and type II at the junction of Yunnan and Yunnan provinces. Dakar or Takahashi method was used to determine focal depth and wave velocity. In this paper, statistical analysis of these data using statistical methods, their planar distribution characteristics, and seven depth profiles were discussed. According to the existing data, the focal depth of the vast majority of earthquakes in Yunnan Province is less than 30 km. Roughly with the Longling-Ruili fault and the Yongsheng-Guanhe fault as the boundary, the focal depths of most parts of Yunnan to the east are generally less than 30 km. There is a northeasterly deep source depth distribution in the western Yunnan region to the west Bands. Within the province, the change of focal depth showed a clear trend of gradually changing from shallow to deep from southeast to north, with the largest change in Jianchuan, Heqing, Lijiang and Ninglang belt. This trend is consistent with the changing trend of crustal thickness. The distribution of virtual wave velocity is basically similar to the distribution of focal depth. Generally speaking, where the focal depth is deeper, the velocity of the virtual wave is also larger.