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| The ROV and Eddy, good to go! |
Today's blog is written by Karl, from the University of Southern Denmark, all about 'Jackson', his Eddy correlation lander....
We are currently about halfway through our 280 nautical mile journey from Mingulay to Rockall, steaming at a steady 11 knots over the deep waters of the Rockall Trough. The scenic views of the islands south of Barra have been replaced by open ocean as far as the eye can see. The sun is shining and ‘Jackson’ (my ‘eddy-correlation’ lander system) is safe back on deck after having had his first ever adventure to the cold-water coral reefs off Mingulay. On top of that, the data looks promising! Life is good...
So what is this lander system all about?
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| Karl watching eddy deploy |
The ‘Aquatic Eddy-Correlation’ lander is a new development in the aquatic sciences. Its main components consist of a ‘Velocimeter’ (an instrument that is able to measure the turbulence within the water) and a very sensitive oxygen sensor, that can sense even the slightest fluctuations in O2 concentrations. These two signals are recorded simultaneously from the same spot around 15 cm above the seabed, 64 times every second. These data are then combined to give the flux of O2 towards and away from the seabed. In our case we can therefore find out how much O2 the cold-water coral reef ecosystem is respiring without interfering with the community in any way. This is valuable information since the conditions that the corals are exposed to at the seabed are not possible to replicate in the lab.
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| Oxygen sensors and velocimeter | |
The ROV provides a fantastic platform for scoping out the best spot to place the lander. Once an ideal spot was found, the ROV positioned the lander on the seabed and returned back up to the surface, leaving the lander to record data. Watching the lander disappear from the ROV video feed for the first time, I couldn’t help but feel slightly daft. It seemed irrational to abandon such an expensive piece of kit at more than 100 metres depth! Reminding myself that it is all in the name of science, and that Jackson is nothing but an amalgamation of expensive electronics and stainless-steel housings, I composed myself enough to become excited about the possibility of collecting new data. I felt more and more confident that we will be seeing the lander again when the ship’s positioning system started to pick up a signal that was being transmitted from the beacon located on the lander frame. Needless to say, the lander was skillfully recovered by the ROV team the following day, intact and fully-functional. Now several hours of data processing await me, and then it’s on to preparing Jackson for his next adventure off Rockall, this time at 800 metres depth! Wish me luck...
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| Eddy out of water |
‘Team Eddy’ signing off...
