Field acquisition: |
Vessel: Thomas Thompson |
Cruise: TN037 |
Start date: 23 Jul 1994 |
End date: 4 Sep 1994 |
Source: |
1. Air gun array: 200, 150, 108, and 80 in3 |
2. GI air gun: 45/105 in3 |
Pressure: 2000 psi |
Shot interval: |
Maximum: 37 m |
Minimum: 25 m |
Streamer: |
Active group length: 25 m |
Number of groups: 6 |
Recording: |
Acquisition hardware: Sun SPARC10 |
Acquisition software: "a2d" |
Data format: SEGY |
Data length: 6-7 s |
Delay: 2-3 s |
Shot interval: 10 s |
Sample interval: 1 ms |
Filters: |
Low: 15 hz (24 dB/oct) |
High: 3khz (24 dB/oct) |
Processing sequence: |
Pick water bottom time (WBT) |
Despike |
Bandpass filter 5-200 Hz |
Geometry definition, insert WBT in header |
Mute to water bottom |
Spherical divergence correction |
Resample (2 ms) |
Notch filter (60 Hz) |
Deconvolution |
Velocity analysis |
NMO correction |
Stack |
Pick and apply static correction |
Finite difference migration |
Time-varying filter: |
Seafloor to 0.25 s: 30-150 Hz |
0.25 to 1.0 s: 20-150 Hz |
1.0 s to end of record: 6-70 Hz |
Gain (500 ms AGC) |
Mute to water bottom |
Notes: Data were processed at the Ocean Drilling Program, Texas A&M University. Processing software: SIOSEIS and PROMAX. Data were processed by Michael Holzrichter and Adam Klaus. NMO = normal moveout. AGC = automatic gain control.