数值模拟激发条件对宾川水库气枪信号振幅的影响  

Effect of Excitation Factors for Numerically Simulation on AirguanSignal Amplitude in Binchuan Reservoir

作　　者：孙楠 孙耀充[3] SUN Nan;SUN Yaochong(School of Earth and Space Sciences,University of Science and Technology of China,Hefei 230026,Anhui,China;Yunnan Earthquake Agency,Kunming 650224,Yunnan,China;Department of Earth and Space Sciences,Southern University of Science and Technology,Shenzhen 518055,Guangdong,China)

机构地区：[1]中国科学与技术大学地球和空间科学学院,安徽合肥230026 [2]云南省地震局,云南昆明650224 [3]南方科技大学地球与空间科学系,广东深圳518055

出　　处：《地震研究》2020年第4期711-719,共9页Journal of Seismological Research

基　　金：地震科技星火计划项目(XH18044Y);震情跟踪定向工作任务(2020010128);国家自然基金项目(41574059)联合资助.

摘　　要：利用有限差分方法,对宾川气枪试验中激发条件对气枪信号振幅的影响进行数值模拟。结果显示:水库水位对信号振幅的影响呈非线性关系,34 m为气枪激发试验的优势激发水位,能产生最强波形振幅能量,而水位变化的影响随距离缓慢减小。通过拟合给出了不同水位变化幅度与其产生的平均振幅变化率之间的幂函数关系,可为实际波形运用中去除水位变化的影响提供理论参考。波形振幅与激发能量及震源沉放深度呈近线性关系,即激发能量越大,震源沉放深度越深,气枪激发效果越好,越有利于进行远距离深穿透地下结构的探测。Using the finite different method,we numerically simulate the effect of excitation factors on airgun signal in Binchuan Reservoir.The result shows that the relationship between the change of reservoir water level and airgun signal amplitude is nonlinear,there is an optimum water level range of 30~35 m for airgun firing test which can excitate the strongest energy of signal amplitude,in addition the influence of water level changing attenuates with distances.We also fit the power equation between the amplitude of water level changing and the average amplitude change rate it produced,so that we can use it to provide theoretical reference for removing the effect of water level changing in actual waveform application.The wave amplitude is linear with excitation energy and towing depth,that is the greater the energy and the deeper of the towing,the better the effect of excitation,the more conducive to detect remote and deep penetration underground structure.

关 键 词：数值模拟 水位 沉放深度 激发能量 信号振幅 

分 类 号：P315.6[天文地球—地震学]