Day two of the cruise: RRS James Cook is traversing along the coast of the UK to reach our study site. We expect to reach the site by tomorrow afternoon and begin the operations. The weather is perfect – a glorious sunny evening!
Cruise activities are steadily gaining momentum…
The determined OBIC team has set up all 25 OBSs (ocean bottom seismometers) ready for deployment. This morning, they tested the beacons that will be fixed on top of the OBSs and prepared their charts for deployment – they look all set! The OBSs will sit on the seabed to detect and record the artificial seismic signals generated by our equipment. The acoustic (seismic) signals will pass through the sub-seafloor geology, bounce off the different rock layers and back up to the seafloor, where they will be detected by the OBS. The data will reveal information about the subsurface geological structures.
The Airgun engineers were also in action this morning, performing tests on the airguns by triggering virtual firing. The airguns provide the acoustic (sound) source for our seismic experiments by releasing a high-pressure blast of air – effectively an underwater ‘bang’. In times (long) past, this was done by lobbing dynamite off the ship!
The Principal Scientist called a meeting at 1400 hours, during which Mark explained the data that appear on different screens of the swath system in the lab – there are so many screens for the watchkeepers to look at whilst on duty! It’s important that we monitor the progress of the experiments as they happen so we can watch out for problems with the instruments.
Following the talk, Jon and Tim briefed about the watchkeeping rules for logging information and how to fill Mammal observing documents – Guys, the jobs are attention-demanding!
The PSO took the science party to the bridge from where the mammal observation is to be done – this is an important job during cruises like this one as there is a risk that seismic experiments could affect marine mammals, so we keep an eye out for what might be in the area. The view is awesome from the top of the ship!
End of day two. It’s time to socialise a bit before everyone gets busy tomorrow. See you then! Good night.