Sunday 24th February
Isis ROV dive 207 went into the 27 degree C, sun-streaked surface waters of the Cayman Trough at 1010h local time this morning. The vehicle arrived at the 4.3 degree C waters 5 km beneath our ship at 1330h, and our final dive to the Beebe Vent Field began.
Once more into the deep
As this is our last dive here, there is understandably a wish-list of final data and samples that each of our science teams would like to collect. Over the past 24 hours I have discussed, cajoled, and compiled these into a hopefully achieveable dive plan, given that we will only have 12 hours at the seafloor.
That plan needs to conform to a realistic arrangement of the ROV payload spaces for deploying equipment and collecting samples, and the dive tasks need to be ordered into the most efficient route on the seafloor. But a dive could be aborted at any time, so the priority of science team needs must also be considered. I hope that balancing act will work for this dive.
Timelapse of ~1 hour in the ROV control centre this evening, compressed into ~1 minute
Our first task today has been to extend our geological mapping of the area, to understand the history of the vents and their mineral deposits here. At the same time, we have been able to investigate the "background" marine life away from the vents, and collect samples of seafloor sediments.
We then moved on to survey the different habitats of the vent field, to check that we have representative samples that reveal their ecology. Next up are samples of venting fluids, for an investigation of the wider impact that vents have on the surrounding ocean.
As midnight approaches, we are nearly done: there is just one more task that we would like to complete.