We finally arrived at Rothera Research Station last week. Another stage of my journey over, and another begins. Actually before we docked was the last serious science for me on the trip. I have had some equipment sitting on the seabed off Rothera for the last two years measuring the temperature, salinity and ocean currents as part of my climate research. One of the really special things about this bit of kit is, we also had a couple of sediment traps down there as well. Now a sediment trap is just like a huge yellow funnel about 90 cm across that catches the debris that falls through the ocean down to the sea floor (we call this marine snow). This snow is always falling in the sea, but in this part of the world it is a bit more interesting because lots of algae grows both in and on the bottom of the sea ice. So when that stuff melts and the algae falls out you get a kind of blizzard falling to the sea floor. What makes the sediment traps really good is on the bottom of the big yellow funnel is a computer controlled sample unit that swaps a sample bottle at the bottom of the funnel every couple of weeks – and that means you get a time series of how much of this snow falls through the year. And of course we put this together with the ocean current data and can try to understand the regional link between climate and biological activity here.
I said the kit has been on the sea floor for a couple of years – but that is not strictly true because every year we have visited and recovered it from the sea floor to download the data, then redeployed it again. But the fact that you have got it back before doesnt mean it is any easier to get this time....
The whole point of this sort of science is you can leave the stuff and it works through the whole winter when you are not around. But out of sight is definately not out of mind. I have woken up loads of times over the last year dreaming of icebergs running the kit over and destroying it.
So it's now about 14 months after the last time I deployed this bit of kit and I am close to where we dropped the kit off.
We stop and lower our hydrophone (a big waterproof microphone) and shout "hello" (an acoustic signal at a special frequency that tells the kit to answer us).
My heart starts to sink and I have a mental picture of the iceberg that must have destroyed the kit. It's one of those moments you plan for but hope won't come. But it has. OK, option A doesn't work, try option B, then onto option C, D and so on.
By 15 minutes I was up to option F and still no answer. Then I heard a tremendous WHOOOSH. A couple of Minke whales were on the surface next to the ship and breathing. I guess they had probably heard our hydrophones and come to investigate. I didn't have time to look but they did distract the people not involved in the science from watching me struggle.
I was pretty tense by option K when finally we got an answer. It was still there and on the sea floor! But was it OK? It took another 20 minutes of struggling before I thought we had finally persauded it to come to the surface.
I turned to the bosun to tell him, and was just in time to see him point, smile and say "there it is Mark".
My large orange float was about 100m from the ship.
In the open ocean with kit floating on the surface it can sometimes be a bit tough getting it on board, but with this ship, this crew and in calm waters I knew the job is done.
It's hard to describe the relief. But it was soon followed by the most amazing tiredness. I have had a couple of months of nightwatches now and I guess every day you are a little more burned out.
As soon as the kit was on board that was me in bed. It was the end of my last night shift of this trip.
When I woke six hours later we were alongside at Rothera.
[Image: Mark Brandon]