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.

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I am currently a second year PhD student at NOC working within the Geology and Geophysics research group on the Arctic Landslide Tsunami Project. This is a five year long consortium project involving 14 different research institutions across the UK. My role within it is to assess the occurrence of very large submarine landslides in the context of climate change. One of the main concerns of the work is that we already know some of the largest landslides on each have occurred during periods of rapid climate change, and it is essential that we understand the relationship between these two phenomena.

The first part of my work is looking at a set of new sediment cores collected on a cruise this summer from the Northern North Atlantic. Myself and Josh were lucky enough to spend a month aboard the RV Pelagia, during which time we collected over 80 new sediment cores from the region.

Josh and I on a recent study trip to Svalbard. 

My main interest at the moment is looking at the Storegga Landslide, which occurred 8200 years ago on the Norwegian Margin. It is of interest as it happened during the coldest years of a climate event known as the 8.2 ka BP event, during which time the UK was approximately 5°C cooler on average than today. Part of my work is looking at cause and effect, which came first and could the cooling have contributed to the landslide, or vice-versa. The second part of my work is looking at older deposits from the same region and trying to date the previous large landslides that have occurred there. These deposits are clear in the sedimentary record, here is an example of what the Storegga landslide looks like after several thousand years of settling:

Why this research matters, is that when the Storegga landslide occurred, it generated a tsunami that affected large parts of the UK coastline. The amount of material moved during the event could cover all of Scotland in 100m of mud, in total 3500 km2. Previous landslides in the area have been even larger, yet we still do not have a reliable date for several of these.

Whilst we are unsure exactly what triggers these events, it is possible to use the mud that accumulates in between the landslides (hemipelagite) to build a chemical profile of the sea surface temperature, the salinity and the strength of the ocean currents. This allows us to put these events in context, and compare the changes that were taking place in the ocean then, to the changes that are happening now.

There are several other research projects that are looking at the potential triggering mechanisms, modelling the oceans and how they respond to this much sediment, the potential involvement of large lake outbursts (Lake Agassiz which covered large parts of North America at the time, suddenly drained into the North Atlantic at c. 8470 years ago), and the possible involvement of methane clathrates.

Sediment coring is one of the most important ways we can build up our records of past events, everything makes its way to the ocean at some point, and the bottom of the ocean is the perfect repository for records of changes to ice sheets, rivers, eroding mountains and oceanic circulation. Occasionally, the cores can be quite beautiful, such as the one below which went through an overturned block of laminated material:

@GeoMillie

The post My Research: Millie Watts appeared first on Exploring our Oceans .

I’m Felicity Williams and I study how sea level changes when the amount of ice on land either grows or melts.

It is very tempting to think of our earth as one large bath tub in which the water level goes up and down uniformly across the entire surface. The real world is far more interesting!

Every location around the world experiences a different sea level for the same amount of water being added to or taken away from the oceans.

Figure 1: Mountainside scoured by a retreating glacier –the Moiry Glacier – which can be seen to the left of the image.

Figure 2: A view down the valley scoured by the Moiry Glacier. Here you can see the edge moraines formed by the ice when it surged down the valley.

This is because when ice grows it squishes down the land underneath it. This causes sea level to effectively rise in that location even though ice is building up on land and so taking water out of the ocean. Conversely when the ice melts, the land springs back and sea level falls, even though more water is being added to the ocean. This process is called Glacial Isostatic Adjustment – and we feel it even today in the British Isles as a result of the great British and Irish Ice Sheet that was centered over Scotland around twenty thousand years ago.

Figure 3: Beautiful corals on the Great Barrier Reef in Australia. We can reconstruct past sea levels using fossil corals that were once alive.

We have some clues as to how sea level changed in the past gained from evidence like fossil corals, and we have some clues as to how much ground the ice sheets covered in past times as the ice sheets can push huge mounds of earth and rubble in front of them as they advance – these are known as moraines.

My job is to pull these clues together, so that we get a better idea of just how variable sea level was in past times – with the intention of applying it to the present day. If we know how fast sea level changed in the past, we have a better idea as to just how variable sea level could be in the future.

Flic.

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My name is Josie Robinson and I’m excited to be a facilitator on the “Exploring our Oceans” MOOC. I’m just entering the 3^rd year of my PhD at the National Oceanography Centre, Southampton, where I’ve been looking at ocean iron fertilisation.

By iron fertilisation I mean the addition of iron, which is a vital ingredient for life along with other essential nutrients, such as nitrogen and phosphorus. Phytoplankton are microscopic marine plants that form the base of the food chain across the world’s oceans, but they can only grow where nutrients are available to them. Large parts of the ocean lack either nitrogen and/or phosphorous, but the focus of my PhD is where phytoplankton growth is limited by the lack of iron, most notably the Southern Ocean. So far in my PhD I have looked at artificial iron fertilisation for the purposes of geoengineering and also natural iron fertilisation, occurring around Southern Ocean islands.

Geoengineering is a controversial last resort if we can’t get our CO₂ emissions under control and reach a critical tipping point with our climate. It would involve the manipulation of nature to avert the worst of climate change. Proposed geoengineering methods range from orbiting space mirrors, to simply pumping CO₂ into the ground. The aim of ocean iron fertilisation would be to increase the amount of CO₂ absorbed by the ocean by artificially enhancing natural processes. This can be done by growing photosynthesising marine phytoplankton in areas it can’t ordinarily grow because of the lack of iron. Whether or not this would work has been an interesting topic for debate in the scientific community and was the focus of my first years study.

Natural iron fertilisation occurs around and down stream of landmass. Iron is found in the mud surrounding islands such as South Georgia and Crozet in the Southern Ocean and is scoured out of the sediment by ocean currents. As a result we see phytoplankton blooms around these islands, in an otherwise baron Southern Ocean. By studying this natural iron fertilisation we can learn a lot about the intricate interactions between the ocean iron and carbon cycles.

In order for me to study ocean iron fertilisation I use a simulation of the ocean, called the NEMO model, which I can experiment with to try and further our understanding of the real world ocean. I work with the … team at the National Oceanography Centre who are continually striving to improve the models representation of the ocean, capturing as much detail as possible and also the changes occurring during the passage of time and changing climate.

I hope you enjoy the Exploring our Oceans MOOC, and I am really looking forward to getting to know you and what interests you about the ocean.

Josie

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