Pn-Pg震相组合测定震源深度方法的应用研究--以广东和河北地区为例

摘要

Based on the improved direct wave ray travel time algorithm,in this paper the regional earthquake focal depths are relocated by using the combination of first arrival phases of Pn and Pg.The relocation indicates that the focal depths in Guangdong network's observation reports are consistent with focal depths given by the new method.But the focal depths in He-bei network's observation report are generally shallower than 3-6 km.And the new results indicate that part of earthquakes al-so exist in lower crustal in Tangshan seismic belt.The new hypocenter depths yielded by the phase Pn-Pg combination meth-od are generally deeper in Tangshan seismic belt,and also the results can reflect the seismic fault information in the further ex-tension.%在直达波射线走时算法改良的基础上,利用天然地震初至震相 Pn、Pg 进行组合的方法,对区域地震震源深度进行重新定位,结果显示,广东台网观测报告里震源深度和这里新方法定位深度总体上吻合较好。河北台网观测报告里震源深度普遍偏浅3 km~6 km,新定位结果显示唐山老震区还存在下地壳地震。Pn-Pg震相组合法对唐山老震区的震源深度定位效果一般更深些,同时也进一步反映了断层构造信息。