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现代地质 ›› 2009, Vol. 23 ›› Issue (6): 1160-1166.

• 地球物理学 • 上一篇    下一篇

隐伏活断层地震勘探正演模拟方法

 兰晓雯1,2,  晏信飞1, 吴何珍3, 田家勇2, 牛滨华1   

  1. 1中国地质大学 地球物理与信息技术学院,北京100083;   2 中国地震局 地壳应力研究所,北京100085;
    3中国地震局 地球物理研究所,北京100081
  • 收稿日期:2009-04-20 修回日期:2009-10-20 出版日期:2009-12-29 发布日期:2012-02-16
  • 作者简介:兰晓雯,女,助理研究员,博士研究生,1978年出生,地球探测与信息技术专业,主要从事地震正演模拟、地震勘探数据处理工作。Email: lanxw@email.eq-icd.cn。
  • 基金资助:

    中国地震局地壳应力研究所基本科研业务专项(ZDJ2009-14);中国地震局地震行业科研专项(200708047);国家自然科学基金项目(40704018)。

Seismic Modeling Method for Shallow Seismic Exploration of  Buried Active Fault

 LAN  Xiao-Wen1,2,   Yan Xin-Fei1, WU  He-Zhen3, TIAN  Jia-Yong2, NIU  Bin-Hua1   

  1. 1School of Geophysics and Information Technology, China University of Geosciences,Beijing100083, China;2Institute of Crustal Dynamics,
     China Earthquake Administration,Beijing 100085, China;3Institute of Geophysics, China Earthquake Administration, Beijing100081, China
  • Received:2009-04-20 Revised:2009-10-20 Online:2009-12-29 Published:2012-02-16

摘要:

浅层高分辨率地震勘探是城市活断层探测手段中最有效、最可靠的方法之一,但是由于隐伏活断层勘探时存在着勘探深度浅、地层的属性差异小以及环境噪声大等因素,导致地震勘探数据信噪比低、反射信号弱等问题,严重影响地震数据的采集、处理和解释。采用一阶应力-速度方程的高阶交错网格有限差分方法, 结合完全匹配层(PML)的边界处理方法和通量校正(FCT)法消除频散的技术手段,对活断层模型地震勘探进行正演模拟,清晰直观地表现了断层处的细微差别,有助于地震勘探中对信号的分析与理解。结果表明,这些处理手段结合波动方程有限差分算法,能够有效实现薄层、弱反射的隐伏活断层模型的波场正演模拟,可有效识别隐伏活断层的断层倾角、断距、规模、跨越范围、断层深度以及断裂带影响范围,为分析这些参数对地震记录的影响提供有力帮助,同时结合实测地震数据的处理、解释,为防灾减灾提供具体有力的判据。

关键词: 隐伏活断层, 地震勘探, 正演模拟, 有限差分方法

Abstract:

The shallow high-resolution seismic prospecting is one of the effective and reliable methods in urban active fault detection. For the shallowness of the object stratum, the tiny difference between the seismic attribute of strata and the ambient noise, it is hard to process and interpret seismic data. In this paper, the staggered-grid high-order difference method of one-order elastic wave equations, which are expressed with velocity and stress applying the flux-corrected transport(FCT) method with a perfectly matched layer (PML) absorbing boundary condition, are used to obtain the synthetic common-shot profile for shallow fault model. The simulated results of fault model show that this method is accurate and distinct. This seismic modeling method is helpful for approximately estimating the location, the depth and the scope of the fault from the synthetic profile during survey, and improving the efficiency of seismic prospecting and the precision and resolution of seismic data processing and interpretation.

Key words:  buried active fault, seismic prospecting, seismic modeling, finite-difference method

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