北部湾6．1、6．2级地震的震源参数和Q_P值特征
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摘要
利用中国数字地震台网（ＣＤＳＮ）琼中台短周期垂直向Ｐ波数字地震资料，研究了１９９４年１２月北部湾６．１、６．２级地震的震源特征，并对震情趋势作出估计。研究表明，北部湾地震的余震应力降和介质ＱＰ值分别为３．６５×１０５Ｐａ和２８５，在震区附近发生更大地震的可能性不大；在东方小震群区，测定的应力降和介质ＱＰ值分别为１．６５×１０５Ｐａ和２６６，符合小震群震源特征；在琼东北地区，应力降不高，ＱＰ值为１９０；海南岛东南的陵水及其海域应力降也不高，ＱＰ值为４８０。这两个地区均存在着孕育较大地震的介质条件，特别是琼东北地区。
The source characteristics of the Ms6.1 and Ms6.2 earthquakes occurred in Beibuwan are studied by using digital seiSmic data of the short period vertical component of P wave,and the earthquake trend is also analyzied.The results show that the stress drop of the aftershocks of the Beibuwan earthquake and their QpValues are respectively about 3.65×105pa and 285.The possibility for occurring larger earthquake is not too large in and near the Beibuwan earthquake region.The determining stress drop andQpvalue are respectively about 1.65×105pa and 266 in the Dongfang small earthquake swarm reston,which are in agreement with the source characteriStics of the small earthquake swarm.The stress drop in northeast Qiong region is not too high and Qpvalue in this region is about 490;and that in Lingshui region and its sea area of southeast Hainan Island also and Qpvalue 480.The medium condictions of larger earthquake preparation exist in both districts,especially,in northeast Qiong region.
The source characteristics of the Ms6.1 and Ms6.2 earthquakes occurred in Beibuwan are studied by using digital seiSmic data of the short period vertical component of P wave,and the earthquake trend is also analyzied.The results show that the stress drop of the aftershocks of the Beibuwan earthquake and their QpValues are respectively about 3.65×105pa and 285.The possibility for occurring larger earthquake is not too large in and near the Beibuwan earthquake region.The determining stress drop andQpvalue are respectively about 1.65×105pa and 266 in the Dongfang small earthquake swarm reston,which are in agreement with the source characteriStics of the small earthquake swarm.The stress drop in northeast Qiong region is not too high and Qpvalue in this region is about 490;and that in Lingshui region and its sea area of southeast Hainan Island also and Qpvalue 480.The medium condictions of larger earthquake preparation exist in both districts,especially,in northeast Qiong region.
引文
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