High-resolution shallow marine seismic surveys off Busan and Pohang, Korea, using a small-scale multichannel system

A small-scale multichannel high-resolution shallow marine seismic survey was designed to improve the quality of high-resolution seismic data using a multichannel array while preserving cost effectiveness and expedience of the conventional shallow single-channel seismic survey. To evaluate the potential of these modified methods, test surveys were carried out off Busan and Pohang, Korea. A 10- or 30-in3 small air gun, 30- or 40-m-long streamer cable and PC-based recording system with A/D converter were used to acquire digital high-resolution seismic data. In the data processing, deconvolution and static corrections were very effective in improving the resolution. Resolution and signal to noise (S/N) ratio were increased by acquiring multichannel data in comparison to conducting the same survey with a single-channel array. In the data of Busan survey, thin internal reflectors with 1–2 m resolution were clearly discernable after processing and compared with 3.5-kHz subbottom profiler data. Faults with ∼0.8 m throw were detected in the data of Pohang survey. The results of this study show that small-scale multichannel seismic surveys may be an effective way to image shallow subsurface structures and can be used in various engineering and environmental applications, sedimentary research and marine resources exploration.