岱海断陷带地区地震重新定位研究

Relocation of the earthquakes in Daihai fault zone

采用双差定位,对岱海断陷带及周边地区2008—2013年地震事件进行重新定位及震源深度研究。重新定位后地震在空间分布上更加集中,部分地震有向构造带趋近的变化,较多地震呈簇集状出现于多条断裂的交汇部位,西南段地震较活跃,不同部位地震数目有明显差异,构造活动存在分段特征,震源密集地区的分布走向明显,可以推测,岱海断陷带西南端存在东西走向和东南走向的发震构造。震源深度结果表明,地震震源深度集中在5—15km,均值为7km。岱海断陷带西南段地震震源深度大于东北段,反映地壳厚度不均匀。

We relocate earthquakes occurred in Daihai fault zone from 2008 to 2013 using double-difference method.The result shows that the earthquakes are more spatially concentrated and in some areas the earthquakes tend to get close to tectonic belts.East-west and south-east seismogenic structures may exit in Southwest section.The average hypocenter depth is 7 km and the seismogenic layer ranges from 5 km to 15 km.The earthquakes in Southwest section are deeper,which reflects the crustal thickness unevenness.