Reflection exploration of earthquakes was conducted in the continental shelf off the north-west Australia, and a report is made concerning the processing of the acquired data. A GI gun was used as the vibration source, and a wave quite similar to a pulse was generated. Hydrophones were arranged with group intervals of 12.5m, and high-resolution field data were acquired. An analog low cut filter was used to suppress the large-amplitude swell noise attributable to sea conditions. A digital filter was designed for the purpose of eliminating coherent noises from other survey ships. At the ultimate stage the f-k filter was applied to each of the shot records, and the effectiveness was verified. The traverse line was as long as 6700km and therefore the design window was set relatively long at 2.0-4.0s in the residual static correction phase. It was found that this setup is effective in improving the continuity of the reflection surface. 5 figs., 1 tab.