基于高分辨率浅剖与钻孔信息对比的金州湾海底声速的统计特征

Statistical characteristics of seabed sound velocity in the Jinzhou Bay based on high resolution sub-bottom profile data

声波在海底沉积物中的传播速度是一个重要参数,弄清海底沉积物中声速的变化规律具有极其重要的意义。以渤海金州湾海域为例,在进行畸变校正的基础上,基于高分辨率浅地层剖面与钻孔数据的对比分析,实现了全新世沉积层和基岩界面以上沉积层声速的准确反演,并采用统计学方法分析讨论了研究区内的声速特征和变化规律,结果表明,全新世沉积层平均声速的95%置信区间为1 449.60~1 655.72 m/s,平均值为1 560.34 m/s;基岩界面以上沉积层平均声速的95%置信区间为1 657.96~1 970.80 m/s,平均值为1 765.63 m/s;研究区内海底地层的声速与埋藏深度之间呈现明显的正线性相关关系,声速梯度为4.18 s-1。

The sound velocity of marine sedimentary sequence is an important parameter.Finding out the changing rule of the seabed sound velocity is of extremely important significance.On the basis of distortion correction,by comparatively analyzing of high resolution sub-bottom profile data and borehole data,the accurate inversions of sound velocity in Holocene and above-bedrock sedimentary sequence are achieved in the Jinzhou Bay,Bohai Sea,China.Then,the characteristics and changing rules of seabed sound velocity in the study area are analyzed and discussed by statistical method.The 95%confidence interval of sound velocity of Holocene sequence is 1449.60 m/s to 1655.72 m/s,and the average is 1560.34 m/s.The 95%confidence interval of sound velocity of above-bedrock sequence is 1657.96 m/s to 1970.80 m/s,and the average is 1765.63 m/s.There is a significant positive linear correlation between the sound velocity of the sedimentary sequence and the burial depth in the study area,and the gradient of sound velocity is 4.18 s^-1.