Thursday 27 November 2014

What's OSCAR all about?

“The Oceanographic and Seismic Characterisation of heat dissipation and alteration by hydrothermal fluids at an Axial Ridge” a.k.a. OSCAR, is an international project funded by NERC (Natural Environment Research Council) linking both geophysics and oceanography.

Diagram of a segmented spreading ridge, showing
the oceanic crust in black, and upwelling mantle
material (orange/yellow) (credit: NOAA)
We are looking at mid-ocean spreading ridges, where new oceanic crust is formed by upwelling magma cooling at the seafloor. This new crust then moves away from the ridge to allow more to fill in the gap, meaning the further you move away from the ridge, the older the crust will be. Generally there is a relatively high amount of heat flow from the crust into the surrounding ocean at these spreading centres, which can affect ocean temperatures, currents and circulation, which are important to Earth’s climate.


A 'black smoker' (credit: WHOI)
Much of this heat flow is thought to be due to hydrothermal circulation: where seawater percolates down into the crust, is geothermally heated, and then re-emerges into the ocean as hot water containing different elements and minerals picked up from rocks in the crust. These ‘hydrothermal plumes’ are often called ‘black smokers’ due to their dark colour from the minerals they contain. The structure of the crust is thought to affect the pattern of hydrothermal circulation, and vice versa.


During the OSCAR project, we will try and look at how the structure of the crust changes as it ages from a spreading ridge, how this is linked to changes in hydrothermal circulation, and the consequent effects on heat flow and oceanographic processes.

The last corner of Trinidad (credit: Jowan Barnes)

In other news, we set sail from Port of Spain this morning, and are now en route to Panama! We had a beautiful sunny morning to leave Trinidad, sailing past a score of smaller islands, and passing between Trinidad and Venezuela to enter the Caribbean Sea. Dolphins were seen in the distance, and pelicans were skimming the water closer to the ship. Overall, a lovely day, bar some minor sea-sickness and a bit of sunburn!

Pelican seen on quayside (credit: Jowan Barnes)



Tuesday 25 November 2014

All aboard!

Yesterday, the first group of scientists joined the James Cook research vessel in Port of Spain, Trinidad & Tobago. There are 5 of us currently on board: Dr Miguel Angel Morales Maqueda (Principal Scientist for the first cruise, physical oceanographer from NOCL), Prof Rob Harris (geophysicist and heat-flow expert, from Oregon State University), Jowan Barnes (PhD student at NOCL), Anna Gluder (Masters student from Bangor, and volunteer!), and Emma Gregory (PhD student at Durham University).  We will try and have a blog post focussed on each person mentioned above so everyone gets a chance to introduce themselves and explain what their role is on the cruise. Myself (Emma) and Jowan are first-timers aboard a research ship, so there is plenty to learn- including our way around the ship which can be confusing!
A view of the Cook from the dockside

The Cook is a research vessel owned by NERC (Natural Environment Research Council), whose home port is at the National Oceanography Centre (NOC) in Southampton. The ship is just under 100 m long, with 8 decks with various purposes, though currently we are mainly sticking to the Main Deck (scientists cabins), Upper Deck (labs) and the Mezzanine Deck. The Mezzanine houses the galley and mess, and the other social spaces for both crew and scientists alike: library, lounge and bar, and the TV room. There is also a gym to attempt to keep everyone active during the long weeks at sea. Everyone on board has their own cabin, complete with bed, desk, shelves, wardrobe and sink, and usually shares a bathroom with one other person. I think the cabins are bigger (and nicer) then some university accommodation I’ve seen!
A standard cabin aboard the Cook
At the moment we are still in port, so our general routine is to get up for breakfast, work throughout the day, and sleep at night, though this will probably all change when we are at sea and proper shift patterns are allocated. Main tasks for now are to set up the equipment and computers, and check all is in order for the cruise.


We all can’t wait to set sail!


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