摘要
已有的地质和地球物理方法无法对年、月、旬等现今时间尺度上的断层活动变化进行有效预测。运用基于地震活动定量指数运算程序的地理信息技术可以解决这个问题。这种方法被应用于贝加尔裂谷系（BRS）及邻区的研究当中。研究发现，断层活动变化发生在以几年为周期的时间尺度上，这无法用区域应力场的变化进行合理解释。沿着穿越贝加尔裂谷系的剖面编制了活动断层图以及地震活动定量指数曲线。提出的这种方法可以根据地震活动定量指数对活动断层进行仔细的分类，从而为解决地震中期预报相关问题开辟了重要途径。这种方法还被用来研究断层现今活动的时空变化和形成机制。研究发现，在实时尺度上断层活动具有高频发生的特征，这种现象可能是由于脆性岩石圈板内和块体内部运动产生的慢变形波的干扰导致的。利用变形波的通过速度可以对活动断层进行分组，各组具有不同的地质和地球物理特征参数，同时还可以对变形波波前的方向以及某一区域内主要断层在实时间隔内（地质上的瞬间）的活动情况进行预测。
The available geological and geophysical methods fail to estimate variations of fault activity in real time intervals, such as months, years or deeades. Using geo-informational technologies, this challenge can be resolved with an algorithm and software based on a quantitative index of seismic activity. Such an approach has been applied to studies on the Baikal rift system （BRS） and its adjacent territories. It is discovered that fault activity is variable in intervals of several years, which cannot be attributed to changes in regional stress fields. An active fault map of BRS and curves of the quantitative index of seismic activity of faults are constructed for the BRS cross-section. The proposed method ensures a detailed classification of active faults by the quantitative index of seismic activity, and thus significantly extends options for finding solutions of problems related to the middle-term forecast of earthquakes. This method has been applied to study spatial and temporal variations, sources, and mechanisms of the recent fault activation. It is shown that fault activation has a relatively high frequency on the real time scale because of the slow deformation waves of disturbance that are generated by inter-plate and intra-bloek movements of the brittle lithosphere. Throughput velocity of deformation waves allow classification of active faults into groups that differ in geological and geophysical parameters. They also allow an estimation of the direction of the deformation wave＇s front and identification of an area of dominating fault activation in real time （geologically instant） intervals.
出处
《地学前缘》
EI
CAS
CSCD
北大核心
2008年第3期337-347,共11页
Earth Science Frontiers
基金
俄罗斯联邦基础研究资助项目（07-05-00251） The research was supported by the Russian Foundation for Basic Research, Grant 07-05- 00251, and Program 16, Project 3 of the Presidium of the Russian Academy of Sciences ＂Dynamics of deformation processes in seismically active regions of Central Asia and focal areas of strong earthquakes＂.
