震源区的应变调整与水氡变化

1976年唐山地震后,随着一系列余震的发生,震源区进行应变调整。根据贝尼奧夫公式,可由唐山地震序列求出震源区相对应变变化过程。此过程与震源区内一水准观测点所测的垂直形变相对变化基本一致。震源区内水氡的变化与相对应变相关。据此相关性进一步讨论提出,震源区內水氡在主震后的上升可能与震源区应变调整、含水岩层宏观裂隙累积增长有关。 

STRAIN ADJUSTMENT IN THE EARTHQUAKE SOURCE REGION AND THE VARIATION OF RADON CONTENT IN WATER

After the Tangshan Earthquake of 1976, strain adjustment took place in the earthquake source region by the occurrence of a series of aftershocks. The relative strain changes in the earthquake source region may be calculated from the energies of the aftershocks by the Benioff's formula. On the whole, these changes are consistent with those obtained from the vertical deformation observed at a geodetic levelling point within the earthquake region. The correlation between the variations of the radon content in water and the changes of relative strain is rather good. Further discussion based on such observations suggests that the increase in radon content in water after the main shock may be related to the strain adjustment in the earthquake source region and the cumulative increase of macroscopic fractures of the water bearing rock formations.