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深拖曳多道地震勘探系统(DTAGS)由声学和地球物理阵列组成,具有220～820Hz的激发震源,一般拖曳于海底之上300m左右的高度.DTAGS系统具有低于6m的勘探波长,比传统地震勘探更小的第一菲涅尔带半径和更大的波数采样空间,因此能够提供高分辨率的海底沉积和构造信息.由于高频扫描和深海拖曳的特殊性,DTAGS震源和水听器相对位置的精确定位是后续地震成像和速度分析的基础,因此DTAGS勘探数据处理质量的关键在于其阵列几何形态的反演.在北Cascadia边缘陆坡天然气水合物勘探的实际应用中,DTAGS系统显示了与低温流体汇集和水合物相关的Cucumber碳酸盐丘和Bullesye冷泉构造在横向和纵向上(海底300～400m深度范围内)的高分辨率沉积和构造特征,为评价水合物的资源状况,研究海底低温热液的运移和汇聚模式,及其对天然气水合物形成和分布的控制机制,提供了丰富的信息.
The deep tow multi-channel seismic exploration system (DTAGS) consists of acoustic and geophysical arrays with an excitation source of 220-820 Hz, generally towed to a height of about 300 m above the seafloor. The DTAGS system has exploration wavelengths below 6 m, Explore the smaller first Fresnel zone radius and larger wavenumber sampling space and therefore provide high-resolution seabed deposition and tectonic information. Due to the particularities of high-frequency scanning and deep-sea towing, the DTAGS source and hydrophone are relatively Therefore, the key to the processing quality of DTAGS exploration data lies in the inversion of its array geometry.In the practical application of natural gas hydrate exploration on the northern Cascadia slope, the DTAGS system shows that the Low-Temperature Fluid Assemblages High-resolution sedimentary and tectonic features of the Cucumber carbonate mound and Bullesye Cold Spring structures associated with hydrates in both horizontal and vertical directions (300-400 m depth of the seafloor), in order to assess the resource status of hydrates, The migration and convergence patterns of low-temperature hydrothermal fluids and their control over the formation and distribution of gas hydrates provide a wealth of information.