Abstract: An advanced technique to accurately invert the array geometry of the high resolution deep-towed multichannel seismic system DTAGS (deep-towed acoustics and geophysics system) was developed for each shot based on previous studies. This technique used picked arrival times of direct wave and sea-surface reflecting wave as constrain conditions, brought the systematic error of the array nodes’ depths and the fluctuation of the seawater velocity into the inversion process, and employed genetic algorithm to simultaneously invert the whole controlling parameters and to achieve globally optimistic DTAGS array geometry. In the application of exploring marine gas hydrate at the North Cascadia margin, the advanced array geometry inversion technique improved the DTAGS imaging quality dramatically, and thus provided full and accurate details of gas-hydrate-related sedimentary and structural features.

Key words: deep-towed seismic system, array geometry inversion, genetic algorithm, gas hydrate

摘要： 在前人工作的基础上, 发展了一套针对高分辨率深拖曳多道地震勘探系统(deep-towed acoustics and geophysics system, DTAGS)阵列几何形态的高精度反演技术。该技术通过拾取的直达波与海面反射波走时共同对反演进行约束, 同时考虑了阵列节点深度系统误差以及海水速度波动的影响, 采用遗传算法对阵列几何形态控制参数进行同步反演, 获得了全局优化的DTAGS阵列几何形态。在北Cascadia边缘陆坡天然气水合物勘探的应用中, 采用改进算法处理后的DTAGS地震数据明显提高了成像质量, 能够提供更为详实的与天然气水合物相关的海底沉积和构造细节。

关键词: 深拖曳地震系统, 阵列几何形态反演, 遗传算法, 天然气水合物