连续形变观测的异常综合指数SAD

The synthetical anomalous degree (SAD) of continuous deformation observation

主要介绍了连续形变异常信息的综合指数 SAD值的有关研究。在连续形变观测单项异常分析方法和参量研究的基础上 ,异常综合指数 SAD较全面地综合了多种前兆参量和方法及同一测点的多台仪器观测信息 ,并顾及了不同台站之间的不同观测情况 ,所获得的结果较真实 ,更具可信度。可作为判定台站连续形变观测综合异常程度的判定值。此外 ,还对华北及川滇地区几次强震前 SAD值的变化进行了分析。结果表明 ,强震前半年时段内 ,震区的连续形变观测点的SAD值会有一个显著增高 (SAD值从平时的 0 .1～ 0 .3的变化范围 ,增高到 0 .5以上 )的前兆过程。特别是震中及邻近地区 1 0 0多公里范围内的测点 ,SAD值出现显著的高值异常 (达 0 .6以上 ) ,未来强震则发生在 SAD值在 0 .6以上的分布地区。异常综合指数 SAD值反映了监测区内与强震有关的连续形变前兆性异常程度和危险程度 ,可用于对未来强震的预测。

In this paper, the study of synthetical anomalous degree (SAC) was introduced. The synthetical anomalous degree was synthesized based on precursory parameters, methods and the information of observations from many instruments. The result is quite true and credible that it can be regarded as the judgement to judge the anomalous level of the deformation. Furthermore, by analyzing the value of SAD before several strong earthquake in North and Southwest China regions, we learn that about half year before the earthquake, the outstanding change of synthetical degree can be observed (the value of SAD, ranges from 0.1 to 0.3 in usual exceeds 0.5). Especially in epicentral region and its vicinity (in the sphere of more than 100 km), the SAD rises to a great high value (>0.6). The strong earthquakes always happen in the area with SAD exceeding 0.6 in the future. The synthetical anomalous degree can reflect the level of the precursory anomaly and of strong earthquakes; it can be used to predict the strong earthquakes. But it also needs appropriate distribution and enough density of observation.