震源到接收台站之间的地层响应函数能够反映地下介质信息。对地震波传播过程中的卷积模型进行推导:记录信号是众多震源子波经过时移加权叠加的结果;通过反卷积方法可去除震源子波信息,提取震源到接收台站之间的地层响应函数;地层响应函数中第一个突跳值对应的时间即为P波走时。在河北赤城-张北地区进行人工震源实验,通过反卷积计算得到该地区地层响应函数剖面图,得出P波波速约6 km/s。利用人工震源系统还可以对地下介质波速变化进行长期动态监测,对地震预测具有一定意义。
The stratigraphic response function between the seismic source and the receiving station can reflect the properties of subsurface medium. The convolution model of seismic wave propagation has been discussed and it is concluded that the recorded signal is the result of time-shift and weighted stack of multitudinous seismic wavelets; The wavelet information can be removed and the stratigraphic response function between the seismic source and the receiving station can be extracted by deconvolution method; The time of the first jump in the stratigraphic response function is the P-wave travel time. The artificial seismic source experiment was conducted in the region from Chicheng to Zhangbei, Hebei Province. We figured out the profile of the stratigraphic response function of this region by deconvolution and concluded that the P-wave velocity is 6 km/s. The artificial seismic source system can also be used to monitor the change of wave velocity of subsurface medium, which is significant to earthquake prediction.
2017,38(5): 66-70 收稿日期:2017-04-11
DOI:10.3969/j.issn.1003-3246.2017.05.012
基金项目:中国地震局地震科技星火计划项目(基金项目:XH16007Y);河北省地震局地震科技星火计划项目(基金项目:DZ20160406027);河北省地震局地震科技星火计划项目(基金项目:DZ20170328007)
作者简介:尹康达(1987-),男,硕士,工程师,主要从事地震监测及台网运维工作
参考文献:
陈运泰.地震预测——进展、困难与前景[J].地震地磁观测与研究,2007,28(2):1-24.
崔仁胜,周银兴,陈阳等.精密可控震源非线性扫描信号优化设计[J].地震地磁观测与研究,2017,38(1):117-124.
林建民,王宝善,葛洪魁,等.大容量气枪震源特征及地震波传播的震相分析[J].地球物理学报,2008,51(1):206-212.
刘喜武,刘洪.地震盲反褶积综述[J].地球物理学进展,2003,18(2):203-209.
王宝善,葛洪魁,王彬,等.利用人工重复震源进行地下介质结构及其变化研究的探索和进展[J].中国地震,2016,32(2):168-179.
王伟涛,王宝善,葛洪魁,等.利用主动震源检测汶川地震余震引起的浅层波速变化[J].中国地震,2009,25(3):223-233.
杨微,王宝善,葛洪魁,等.精密控制机械震源在地下介质变化监测中的应用研究现状[J].地震研究,2015,38(1):25-34.
杨微,王宝善,葛洪魁,等.精密控制机械震源特征及信号检测方法[J].中国石油大学学报(自然科学版),2013,37(1):50-55.
杨微,王宝善,刘政一,等.不同激发环境下井中气枪震源特征研究[J].中国地震,2016,32(2):231-240.
翟秋实,姚华建,王宝善.气枪震源资料反褶积方法及处理流程研究[J].中国地震,2016,32(2):295-304.