Transect: Slave Northern Cordillera Lithosphere Evolution (SNORCLE)

Processed By: Lithoprobe Seismic Processing Facility (LSPF)
Date Processed: Nov 1996-May 1997

Line 1 Migrated Structure Stack

Location: Western Northwest Territories
Shot Point: 101-12175

No. Processing History Line 1
1 Diversity Stack of Unstacked Sweeps No resampling

Record Length
32 s

Sample Interval
0.004 s
2 Extended Correlation Using recorded pilot sweep; Sweep correlated off end (self-truncating)

Output
Full 32 s
3 Noise Corrections 60 Hz notch filter (only on records contaminated with powerline noise)
4 Crooked-Line Geometry 'Crook' used

Bin
30 m by 1500 m
5 Pre-Statics Editing Trace edits
First breaks picked; Bad traces flagged
6 Refraction Statics Calculated using GLI3D

Elevation Statics
Implicit in solution

Weathering Velocity
1000 m/s

Replacement Velocity
6000 m/s

CDPs (1015-37500)
Two layer model; Offset: < 5000 m

Datum
Stripped to - 200 m
Replaced to +200 m

CDPs (37501-45900)
Two layer model; Offset: < 8000 m

Datum
Stripped to - 200 m
Replaced to +200 m

CDPs (45901-78540)
Two layer model; Offset: < 8000 m

Datum
Stripped to base of lowest layer
Replaced to +200 m

CDPs (78541-121755)
One layer model; Offset: < 8000 m

Datum
Stripped to base of lowest layer
Replaced to +200 m
7 Velocity Analysis Every 100th CDP

Constant Velocity Stacks
10 s

Analysis
50 adjacent CMPs stacked; Increments: 100 m/s

Refractor Velocity
(Shallowest refractor velocity)-(6800 m/s)
8 Mute Every 20th shot record picked
9 Residual Statics Calculated using Super_fold (Sun/Insight software)

Time Window
2-6 s

Iterations
5

Maximum Shift (per iteration)
+/- 0.032 s

NMO Corrected CDPs
3 (per super CDP)
10 CMP Gather Yes
11 Pre-Stacking Processing Removal of dead traces
12 Mute First break
13 Amplitude Adjustment Linear AGC

Window
0.8 s
14 Deconvolution Predictive; only for CDPs (1015-87070)

Gap
0.04 s

Operator Length
0.124 s
15 Spectral Balancing Only for CDPs (87071-121755)

Spectrum
10-70 Hz (in 10 Hz panels)
16 Field Statics Yes
17 NMO Correction Yes
18 Trim Statics Yes

Window
3-8 s

Maximum Shift
+/- 0.012 s
19 Stack Nominal 125 fold
20 Scaling Energy balance (on second window)

Window
8-16 s
21 Noise Attenuation FX deconvolution (using FXDIP)

Window (sliding)
50 traces by 0.2 s
22 Filter Coherency (using smb_smooth)

Aperture
21 traces

Maximum Slowness
0.008 s/trace

No. Slowness
21

Semblance Exp
1

Bias
0 %
23 Migration Using psmig_fast

Time/Velocities
(0 s: 5000 m/s); (11.5 s: 5500 m/s); (12.5 s: 7000 m/s); (32 s: 7500 m/s)
24 Filter Coherency (using smb_smooth);
Same parameters as 22)coherency filter
25 Scaling Time Variant (using tv scale)

Scale Factors/Time
(0 s: 2.5); (1 s: 2) ; (2 s: 1); (11 s: 1); (15 s: 2.5) ; (32 s: 2.5)

Other Formats Processed Comments
Structure Stacks Yes
DMO Stacks No