曹颖,付虹,张海江,陈余宽,黄江培. 2018. 云南普洱糯扎渡水库蓄水前后P波速度结构变化特征. 地震学报,40(6):701−718. doi:10.11939/jass.20180028. doi: 10.11939/jass.20180028
引用本文: 曹颖,付虹,张海江,陈余宽,黄江培. 2018. 云南普洱糯扎渡水库蓄水前后P波速度结构变化特征. 地震学报,40(6):701−718. doi:10.11939/jass.20180028. doi: 10.11939/jass.20180028
Cao Y,Fu H,Zhang H J,Chen Y K,Huang J P. 2018. Characteristics of P wave velocity structure changes before and after impoundment in Nuozhadu reservoir,Pu’er,Yunnan. Acta Seismologica Sinica40(6):701−718. doi:10.11939/jass.20180028. doi: 10.11939/jass.20180028
Citation: Cao Y,Fu H,Zhang H J,Chen Y K,Huang J P. 2018. Characteristics of P wave velocity structure changes before and after impoundment in Nuozhadu reservoir,Pu’er,Yunnan. Acta Seismologica Sinica40(6):701−718. doi:10.11939/jass.20180028. doi: 10.11939/jass.20180028

云南普洱糯扎渡水库蓄水前后P波速度结构变化特征

Characteristics of P wave velocity structure changes before and after impoundment in Nuozhadu reservoir,Pu’er,Yunnan

  • 摘要: 基于云南省糯扎渡水库台网17个台站所记录到的2009年11月至2014年9月期间的5 247次地震的P波绝对到时资料和相对到时资料,以及波形互相关得到的相对到时资料,采用双差地震层析成像方法联合反演了糯扎渡水库库区蓄水前和蓄水后2011年11月30日至2012年12月31日及2013年1月1日至2014年9月30日这3个阶段的震源参数和三维P波速度结构。结果显示:糯扎渡水库蓄水后,水库库区地震的发生频次增多,经重定位后的震源深度大多在10 km以内,尤其以5 km以内的居多,与前人得到的水库诱发地震震源深度小于10 km的结果基本吻合;随着蓄水量的增加,库水沿断层渗透,孔隙压力变化导致地震增多的区域延伸至左岸支库黑江和库区回水至库区中段的澜沧江段,并进一步向威远江和小黑江延伸,这些区域的P波速度降低;整体的水库渗水作用最大深度不超过7 km。

     

    Abstract: Using both absolute arrival time, relative arrival time and waveform correlation data of Nuozhadu reservoir earthquake events, we obtained seismic relocation and 3D P wave velocity structure of three periods by double-difference seismic tomography method. The results show that after the reservoir impoundment, a large number of earthquakes occurred at the reservoir area, and the aftershocks after relocation is mostly located at the depth within 10 km, especially in the range of less than 5 km, which is basically consistent with the previous result that the depth of reservoir-induced earthquake is less than 10 km. With the increase of water storage, the reservoir water penetrates along the fault, the pore pressure changes, which causes earthquakes-increased-area to extend to the Heihe river and the middle part of the Lancangjiang river, and further to the Weiyuanjiang and the Xiaoheijiang rivers. The P wave velocity in these regions is reduced. The maximum depth of the overall reservoir seepage is less than 7 km.

     

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