Airgun Operations and Source Reliability
The ETOMO seismic survey provides multi-scale imaging of the Endeavour segment.  The 3 primary shooting plans are referred to as: (i) Undershoot, (ii) Crustal grid, and (iii) Hydrothermal grid.  
While all data will contribute information on crustal and mantle structure beneath the Endeavour segment, broadly speaking the 3 shooting plans provide constraints as follows:
Undershoot:  Shallow mantle structure beneath the entire ridge segment.
Crustal grid:  Three-dimensional structure of the crust along the ridge axis, including the axial magmatic system.
Hydrothermal grid:  Detailed, three-dimensional structure of the magmatic-hydrothermal reaction zone above the segment-centered AMC.
Airgun operations
Throughout the airgun survey -- which began August 26 and ended September 11 -- there was not a single power-down or shutdown due to either marine mammal mitigation or inclement weather.  During this 17-day-period the Langseth 36-gun, 6600 cu. in. array was operated at full strength, except during short periods when gun maintenance was required.  In view of the extended mitigation radii imposed on our experiment, this is a remarkable achievement.
Airgun shakedown time:
Consider modifying the MGL timelines to include perhaps up to 24 hours of gun maintenance at the start of a survey.  We had 2 new umbilicals on board for our experiment and there were teething issues. The "shakedown" time would allow the crew to test, retest, and solve problems.  For the PI, if that time is not used, then it turns into science time.
The line naming convention, shot log file description, and maps of the airgun lines and shots can be found in Appendix A2:  MGL0910 Seismic Survey Summary.
Two airgun tow depths were used during the survey: 15m and 9m.  The 15m tow depth was used at the start of the survey to increase the low frequency content of the signal.  The 9m tow depth was used for the remainder of the survey to provide the cleanest source signal.
  * Shot at 15m gun depth: Lines 2, 2R, 3, 3R, 4, 5, 37, 38 (Sequence 1 through 8)
  * Shot at 9m gun depth: Lines 1, 2A, 5A, 6, 7 through 35, 39 & 40 (Sequence 9 through 45)
Percentage of full power shots (number of shots, length of track line for shooting, days of shooting)
ETOMO_Shot_Vol_Hist.pdf
Spreadsheet for ETOMO MGL0910 giving the shot volume for each shot.  The columns are:
Line #    Seq #    Shot #    Shot Volume (cu)    Volume Percentage
Max. Vol. = 6600 cu (4 strings, 36 guns)
ETOMO_Shot_Volumes.xls
ETOMO line and sequence numbers, min and maximum shot number for each line and line length.
ETOMO_Shot_Lines.pdf
MATLAB files for Stingray format
srEvent.mat
srEvent.mat
create_srEvent.m
read_obsip_shotlog.m