High-resolution seismic data processing and preliminary results for gas hydrates in the Makran subduction zone

Integrated geophysical survey has revealed that the Makran subduction zone in the northern Indian Ocean is rich in hydrates resources. Recently, high-resolution multi-channel seismic data have been collected by the authors to investigate hydrates and hydrates-related fluid activities in the area. We analyzed the characteristics of the original seismic data, processed the data following a standard data processing flow, and obtained good results. Using the newly collected and processed seismic data, we have not only identified the classical BSR, but also found the phenomena of non-classical BSR and double BSR. The presence of double BSR indicates that the hydrate in this sea area is in a complex dynamic manner, which may have significant implications for gas hydrate investigation in the area. Owing to the short offset of the seismic data, which is only 1300 m in maximum, the quantitative analysis and fine characterization of hydrate in this area are limited. In this paper, the influence of offset on hydrate exploration is analyzed based on the data of short offset collected from this survey as well as the theoretical formula. It is suggested that the offset is also a parameter which needs to be optimized in hydrate exploration.