Model-Based Identification of the Base of the Gas Hydrate Stability Zone in Multichannel Reflection Seismic Data, Offshore Costa Rica

Table 2

The processing flow applied to profile BGR99-46 is divided into two parts. The offset stacks are created after the application of a band-pass filter and amplitude recovery, while the full CMP stack is created after an additional deconvolution and automatic gain control (AGC). Finally, the profile is either migrated in depth (for retrieving BSR depths) or migrated in time (for BSR interpretation).

Processing steps	Parameters
Ormsby band-pass filter	3-6-60-120 Hz
Normal Moveout (NMO) velocity analysis	Every 100 CMP (∼625 m)
True amplitude recovery (TAR): spherical divergence correction	𝑔(𝑡)=𝑣^2(𝑡)^∗𝑡/𝑣^20^∗𝑡0 [37]
Offset Amplitude Recovery (first order correction of source and receiver array geometry)	Mean frequency, RMS velocity function, gun array length, receiver group length (as listed above in Table 1)
Offset CMP stacks	Every 50 channels, offset range: 625 m
Predictive deconvolution	Operator length: 50 ms, predictive distance: 16 ms
NMO correction	NMO stretch mute values: 30%, 100%
Automatic gain control (AGC)	Time window: 500 ms
CMP stack	Mean
Kirchhoff time/depth migration	Max. dip: 25^∘, max. frequency: 80 Hz, smoothed velocity field