Instruments, events and the science – Mia Taylor

Blog-Greenland-coastEarly August 2016

We have been at sea over a week; the weather is fine, I’ve dodged the seasickness bullet and am learning about life on the ship, all is well.

To provide some background, the focus for the scientists on this cruise (DY054) is to carry out a number of data capturing events. These often involve using instruments and equipment such as CTD’s, moorings and floats to collect data and water samples, which can later be analysed. All of these events are carried out in specific locations and many derive information from the ocean between the surface and the sea floor, capturing data on salinity, temperature, pressure and more.

The mooring and CTD stations that we are visiting are on a straight-ish line between Greenland and Iceland, largely covering the Irminger basin. The moorings are done in the day and the CTD stations at night. All the scientists and many of the crew are on shifts so that the work can be covered over a 24-hour period, it’s a busy time and there is always someone around.

After leaving Iceland it took a few days to make it to our first CTD location near the coast of Greenland. We arrived just as dawn was breaking at around 5am to see icebergs and glaciers twinkling in the distance, barely visible in the cloudy hazy light, and red flashes from the lighthouse at Prince Christian Sound. It was a magical sight.

3.mooring1-lrSoon after that, the first moorings began; M1 and M2 were recovered, having been underwater and actively collecting data for the past year. This is the first time OSNAP have returned to the moorings since they were deployed so bringing them to the surface and retrieving their data was an exciting prospect, as was seeing their condition for the first time since spending a year beneath sea level. Recovering the moorings requires hauling them out of the ocean and removing and cataloguing the instruments. It’s heavy work and it’s cold out, plus due to the high pressure in the area the waves are rolling with more swell than the last couple of days, but the NMFS technicians who are organising the operation have the process efficiently choreographed and everything ran smoothly. Once all of the M1 and M2 2015-16 moorings were out of the water (all of which were fine, with the addition of some biology to a few buoys) a reconditioned set were ready to go back in. If you are not familiar with what the mooring’s are, let me try and explain: one mooring includes groupings of about four buoys incrementally attached along a long line of wire and between these groupings data collecting instruments are further attached. Many of these instruments look cylindrical and are made from a combination of metals to prevent corrosion. The wire is long – M1 was 2059m in length – at the end of the wire a heavy weight is attached, which is designed to sink to the seabed pulling the wire and the buoys down with it so the line and buoys float vertically upwards, securing the instruments for data collection at different depths. When it’s time for the mooring to return to the surface for data collection an acoustic release mechanism triggers the wire to detach from the weight and due to its buoyancy the mooring floats back up to the surface. M1, M2 and now M3 reached the surface intact and untangled making it easier for a technician to catch it and draw it back to the ship.

2.mooring2-lrTo successfully drag down the buoys the weight needs to be significant, for the redeployed M1 and M2 moorings a small part of a massive anchor chain had been chosen, to give an idea of its scale, each chain link is about the width of my forearm. It made a dramatic sight when held aloft by the winch and hanging between the gantries before it was dropped to its watery grave.

In the evening, having completed work at moorings M1 and M2 the ship headed back closer to Greenland for more CTD stations and the launching of a number of RAFOS floats. The CTD consists of a frame with a series of instruments attached to it, which is lowered to the seabed and then returned to the surface. As it comes up it collects water samples from specific depths from which salinity and nutrients can later be analysed. The CTD is an interesting looking piece of equipment and one that I have been spending a lot of time with, the notion of bringing sea water to the surface from inaccessible depths speaks of trying to capture something of the transience of the ocean currents, many of which are from different locations around the world and only temporarily in this spot. More on this next time…

The ship at night is very peaceful and although the ship lights are bright they are the only ones that can be seen in the darkness. I had expected that being in the middle of the subpolar North Atlantic I would feel at the mercy of the expanse of ocean around me, emotionally as well as physically, and for the first few days I do. I can’t think too much about the vastness of space (and lack of solid ground) to my left, right, above and below lest a feeling of panic arise. However, this passes and perhaps because much of my time on ship has been spent with people, in comfort and focusing on the science, it protects my mind from wandering to the possibilities of what is outside.

1.CTD-lrBut not entirely, as well as the science I’ve been learning about the engineering of the ship and how it sustains life in the ocean wilderness.

There is also the social side of being on the ship; the science team includes researchers and students from around the world and the crew, many of who have spent much of their life at sea. Everyone has a story to tell and often at dinner these surface; from tracking polar bears and the different paces that glaciers melt, to ships meeting in the middle of the ocean to exchange salutations.

In my next post I’ll write a little more how I have been approaching the experience from the perspective of making art, more soon…

For different voices from the cruise, see the blog: http://www.o-snap.org/news-events/blog/

 

 

 

 

 

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