Our last day of science sampling and we are collecting water just above a site where we suspect there is low-temperature fluid flow at the seafloor 2.5km below the ship.   This is the site that in 1974 was named TAG after dredging hydrothermal deposits from the eastern rift-valley wall. I worked on these precious samples much later in the 1990’s and demonstrated that hydrothermal neodymium could be traced in these ferromanganese crusts demonstrating that they formed from low-temperature vent fluids rather than from seawater. We want to see what we can see in the deep water over this site and measure the input from the seafloor.

Over the last 38 days we have put our sampling rosette into the deep water 83 times and collected nearly 30,000 litres of seawater for processing, filtering, measuring and archiving. We have pumped over 45,000 litres of seawater through our deep sea cartridges to strip out natural radioactive isotopes that we use measure time in the deep sea. We have filled the container on the aft deck with over 100 crates of samples carefully wrapped for transport around the world to our labs in the UK, the US and elsewhere. Our physics team have made over 20 million measurements of turbulence through the water column and measured the plumes wafting through the deep waters in intricate detail.

We have steamed 4200 nautical miles since we left Southampton and have over 1000 to go to get to Guadaloupe. We have drunk over 7000 cups of coffee and eaten nearly a tonne of potatoes and over a 1000 rashers of bacon. We’ve hit the gym (perhaps because of the potatoes) and collectively rowed, run and cycled thousands of kilometres. We’ve played 350 games of cribbage, nearly 500 games of table football and some challenging games of darts when the ship is rolling.

All 52 people on the ship have worked (and played) really well together on this expedition – we have made new friends and close collaborations that will last a long time. On this long passage south to Guadaloupe we are drafting the ideas for the next proposals, practicing the talks for the big conferences coming up in 2018 and of course getting our fancy-dress costumes designed and made for the ‘RPC’.

The post Our deep-ocean expedition in numbers appeared first on Exploring our Oceans .

We still ‘sail’ in rather larger science teams for much shorter periods of time. The rhythm of work on a ship and the lowering and hauling of wires is very familiar. We collect water samples in large bottles that can be closed remotely at depth and are arranged around an array of in situ sensors that give us real time data of ocean properties as we sit in the lab. The samples are recovered at awkward times of day and night – these samples need to be processed immediately to catch the helium atoms that escape out of the sample, the oxygen samples that are compromised as soon as the tap is opened, the microbial and chemical measurements of trace amounts of rare elements that we use to understand the scale and timing of ocean processes. We pump tonnes of water through cartridges to strip out radioactive isotopes that help determine the timescales in the deep ocean.

All this happens in slick sequence time and time again as we progress South along the volcanic ridge towards the subtropics. After a couple of weeks we are a great team – called on deck at odd hours to process samples under ultra-clean conditions, careful not to contaminate that water from the deep. Make decisions, move on South.

The key to effective work on the ship is of course how well this team works. You would all recognise the dynamics – the Captain is in charge of the ship – the Chief Scientist is in charge of the programme and together they make decisions every day to curtail a bit of this, cut a bit of that, move on if this isn’t working. The rest of the team are here to get the most out of this fantastic opportunity to track all the known volcanic vents in this region.

Ocean expeditions are fabulous training grounds for the next generation of scientists. We have an undergraduate student from California, a POGO funded postgraduate student from Malaysia, a whole group of PhD students from Southampton and Liverpool and the graduate students from collaborating labs in the US and France aboard. They work relentlessly round the clock and still have the energy to have fun – friendships made at sea last a lifetime.

The ship is a melting pot for people from all sorts of backgrounds, all sorts of experiences, all sorts of life stories and these are shared during the night shift over cups of Maeve’s espresso. The bridge calls down to point out those things that we can only really appreciate out here – dolphins on the starboard bow, alignment of Jupiter and Mars off the port deck.

The best part of being at sea is the freedom to focus on the task at hand and nothing more, nothing less. Time slows down, problems are solved, solutions are found, new data is stuck to the walls, new ideas forged as we each contribute to the picture emerging of plumes of metals wafted deep along the ridge. I love the rhythm of the days and nights – the sunsets and sunrises, the slow passing of time. We love the singularity of purpose.

The worst part is the severing of connections with home over the first few days and the vague feeling of institutionalisation and repetition that takes over after several weeks – all lifestyle decisions are out of your hand – what you eat, what you drink, when you sleep, when you do laundry, how you exercise, who you mix with.

The FRidge team is exceptional. I have made new friends, really cemented some work relationships and am looking forward to working with these great scientists over the next few years to get these samples measured and our new ideas out into the community and beyond.

The post Fair winds and following seas appeared first on Exploring our Oceans .

The post Seawater density appeared first on Exploring our Oceans .