南黄海海相地层速度的提取及其特征

南黄海盆地特殊的地震地质条件导致准确获得海相地层速度存在困难。基于本区的多道地震资料，联合使用多数据质控速度分析、初至波层析反演及层控网格层析反演3种方法，提取出了较为可靠的海相中-古生界速度信息。结合提取的地震速度及下扬子区已有钻井信息，总结了南黄海主要海相地层的速度分布。本区海相地层速度整体呈高低相间分布结构，存在速度的突变和倒转。海相下构造层速度高，不同地层间速度差异较小。由于海相下构造层无钻井资料约束，获得的速度信息仍存在不确定性。

Extraction of seismic velocity of marine strata and their characteristics in the South Yellow Sea basin

It is difficult to acquire accurate seismic velocity from the marine strata in the South Yellow Sea Basin due to its special seismic geological conditions. From multi-channel seismic data, we extracted reliable Mesozoic-Paleozoic velocity of marine strata by combining the velocity analysis together with multi-data controlling, first-break tomographic inversion and layer-constrained grid tomographic technique. The velocity distribution pattern of marine strata in the South Yellow Sea is then summarized according to extracted seismic velocity and drilling information from the Lower Yangtze region. The distribution of strata velocity in this area shows a pattern of alternation of high and low velocity with mutation and inversion. The marine lower tectonic layer is high in velocity and the velocity difference between layers is small. The velocity distribution of marine lower tectonic layer is still uncertain because of lacking in drilling data in the sea area.