Table 21.

Table T21. A comparison of VSP check-shot data with depth estimates derived from physical properties and logging measurements.

VSP
depth
(mbsf) VSP TWT
(ms) VSP TWT
(ms bsf) Predicted
depth
(m) Error
(m)

378.1
3405.7
428.8
377.25
0.85

389.1
3419.6
442.8
390.26
-1.16

398.1
3429.8
452.9
399.65
-1.55

408.1
3438.8
461.9
407.94
0.16

419.0
3454.8
477.9
422.87
-3.87

429.1
3465.6
488.7
433.23
-4.13

439.1
3475.6
498.7
442.42
-3.32

449.2
3485.6
508.7
451.80
-2.60

459.5
3497.6
520.7
462.96
-3.46

VSP depth (mbsf)	VSP TWT (ms)	VSP TWT (ms bsf)	Predicted depth (m)	Error (m)
378.1	3405.7	428.8	377.25	0.85
389.1	3419.6	442.8	390.26	-1.16
398.1	3429.8	452.9	399.65	-1.55
408.1	3438.8	461.9	407.94	0.16
419.0	3454.8	477.9	422.87	-3.87
429.1	3465.6	488.7	433.23	-4.13
439.1	3475.6	498.7	442.42	-3.32
449.2	3485.6	508.7	451.80	-2.60
459.5	3497.6	520.7	462.96	-3.46

Note: VSP two-way traveltime (TWT) is converted to two-way traveltime below seafloor (bsf) in column three for comparison to depth measurements made relative to the seafloor.