CONCLUSIONS

Reprocessing of NT62-2seismic line of western Nankai Trough has been conducted to focus on the character of the distribution of Bottom-simulating reflector（BSR）associated with the base of gas hydrate stability zone.Although there are some indicators of BSRs on near-offset profile，better images of BSRs can be obtained by stack and migration.On the near-offset seismic profile BSRs are not clear because of low signal-versus-noise.Stack will increase the signal-versus-noise.While the BSR amplitude usually increases with the offset，stack will include the larger energy of far-offset channels.So BSRs become clear on stack profile.Migration collapse the diffraction and put the energy back to the reflection or diffraction point，so good image of BSRs can be obtained by migration.Characters of strong amplitude of BSRs can be easily seen on instantaneous amplitude profile.It must be pointed out that seismic data processing and the BSR characters in this paper are based on conventional multi-channel seismic data.And because different seismic data from various acquisition methods have different frequency range，their data processing and BSR characters are different from that of conventional seismic mrthods.This paper gives an example of data processing for BSRs in western Nankai accretionary prism which is a typical gas hydrate distribution region.It maybe useful for actual data processing and analysis of gas hydrate BSRs in Chinese Sea region［10］.(https://www.daowen.com)