Before getting on with 25 Ocean Bottom Seismometer (OBS) deployments, water column sound speed measurement and patch tests were performed. Very accurate water column sound speed profiles are required for recording correct bathymetry. Patch tests are done to calibrate various sensors of the multi beam bathymetry acquisition.
The first OBS to go into water was OBS_19. The deployment started at c. 0130 hours and the last one to deploy was OBS_1 at c. 0700 hours.
Following OBS deployment, we prepared for the Sparker (High frequency seismic source) acquisition. However, data acquisition with the Sparker had been halted for some technical problems.
Soon after it, the air guns were ready to go into the water. Mammal observation protocol has been followed before air guns started firing with full power. Also, one watchkeeper was assigned the duty of mammal observation during the survey. We have three airguns firing at full power of 700 cubic inch volume. With this start, we begin the Bolt Asterisk Survey.
We are acquiring the last line of the survey at 0530 hours, 29th August. The next survey to follow is the grid survey.
See you soon with grid survey updates 🙂