pre-seismic

The pre-seismic and post-seismic stress direction can be statistically determined by a large collection of foreshock and aftershock focal mechanism data while the stress drop can be determined through the source fracture inversion from seismic wave data or crust deformation data.

地震前后的应力方向可根据大量前震和余震震源机制统计给出；地震应力降可通过地震波或地壳形变资料的震源破裂反演研究得到。

In energy resource seismic prospecting, to best realize time difference correction of pre-stack tilted stratum, advance velocity analysis and overlay precision, present a sort of celerity realize pre-stack partial migration algorithm, called migration to zero offset ( MZO) algorithm.

在能源地震勘探中，为了更好地实现叠前倾斜地层的时差校正，提高速度分析和叠加的精度，提出了一种快速实现叠前部分偏移的算法，即零偏移距化（MZO）算法。

The radiation pattern of seismic waves is dependent on the form of motion of the medium around the focus at the time of earthquake which is connected not only with the pre-existing stress before earthquake but also with other factors such as the geological conditions within the focal region.

地震波辐射图型取决于地震时震源介质运动的方式.它不但与震前存在的应力有关，而且依赖于震源区的地质条件等因素。