能量屏蔽作用的类型、形成机制及应对方法

对不同地区地震波传播条件进行分析,认为能量屏蔽作用的产生机制有3种:一是强反射界面引起反射型能量屏蔽；二是强黏滞层剧烈吸收损耗引起的耗散型能量屏蔽；三是粗糙面上或非均质介质中的地震波散射引起的散射型能量屏蔽.有时强能量耗散带与强反射界面伴生,产生双重能量屏蔽作用.根据3类能量屏蔽作用机制,提出克服或减少能量屏蔽作用的7种方法:①优化测线部署避开强能量耗散带和散射带；②从激发、接收方面增加透过能量；③优化观测方式避开屏蔽段；④采用高密度地震勘探增加有效接收道；⑤用处理手段消除由强反射界面衍生的多次波、折射波,以及屏蔽带衍生的其他干扰；⑥用转换横波勘探以增大强反射界面的最大透射能量窗；⑦黄土塬区适当结合弯线勘探以减少黄土层的强吸收屏蔽和黄土层底界的强反射屏蔽.

Types of energy shielding effect, formation mechanism and countermeasures

By analyzing the seismic wave transmission conditions for different areas,three types of formation mechanism of energy shielding effect were proposed.Besides the energy shielding effect caused from strong reflection interface which is named as reflecting shielding,there are two mechanisms which greatly reduce the transmission energy and greatly degrade the seismic data quality.One is named as dissipation shielding where there are one or more strong viscous dissipation layers absorbing most of seismic energy...