Sampling carried on throughout the night and around 9am an accoustic release instrument was attached to the CTD to test it was working properly at depth before deploying it later with the mooring about to be recovered and serviced. This mooring had been down for 16 months and had long since run out of battery power. The mooring was located and recovered without any problem and was dismantled on deck. Students took this opportunity to write their names on it!! I had to join them!!
Today, Alex Griffiths, one of the NOC students, is writing his blog.
It was an honour to hear that I would be an integral part of
the A Team. The 12-4am watch makes you fully appreciate the mystery of the
Oceans and the extensive dark abyss that surrounds us. The day started like any
the other; several CTDs were deployed and various parameters were sampled.
However, this shift was, relative to previous watches, very quiet, less hectic
and more relaxing. To add some excitement to the monotony of this watch, Jason
Dobson and I decided to play some “bangin tunes” in the Deck laboratory,
leading the way with S Club 7.
By mid morning we had arrived at the Wyville-Thompson Ridge
and at 11am the mooring that had been collecting data for over a year was
recovered. I have spent three years studying physical oceanography and the
methods used to measure currents. I have read literature that not only explains
but illustrates the materials and methods through various diagrams and photos,
yet I have never seen a mooring. I couldn’t let this opportunity pass.
ON DECK WORKING HARD-
BIG BUOY OCEANOGRAPHY
The Extended Ellett Line cruise has been a real eye opener,
giving me a true taste of the seawater in an Oceanographer’s world, beyond the
lecture theatres and the ludicrous 5,000 word assignments. I am not saying that
this has been an easy going trip, on the contrary it has been tiresome, but
with top Chefs and quality food, I can understand now why all my professors are
never at the NOCS, never reply to my emails and are always sailing the seven
seas.
Back to Linda
The A team that Alex mentions above named all the other teams too - the living dead (4-8), the expendables (8-12) and the slackers (day shift). Needless to say, the other teams have been suggesting what A stands for and none of it flattering.
Wednesday 8th August
The last CTD was done at 10pm last night and the 18 hour steam to George Bligh Bank began. Shortly after this, Charlotte Marcinko from NOC made an interesting observation which she recounts here.
Last
night just after the last CTD came on deck at the Wyville-Thomson Ridge and we
began our steam to the George Bligh Bank, at around 23:00 GMT, flashes of blue
light could be seen at the sea surface.
This eerie blue light was caused by small single celled plankton known
as dinoflagellates the light they emit is called bioluminescence.
Figure 1: Dinoflagellates are single
celled plankton that live in the oceans in the euphotic zone.
Last night the bioluminescence of dinoflagellates
living at the sea surface was being stimulated by the movement of the ship.
Standing in the dark on the aft deck where the ships propellers were churning
up the water, causing lots of turbulence, we could see the water glowing bright
blue. Unfortunately, our instrument to
measure bioluminescence on this cruise has broken so we weren’t able to collect
any data on how bright the bioluminescence was. Sometimes things break at sea
and there is no way to fix them until we get back on land and order new parts.
Figure
2: Example of the bright blue bioluminescence emitted from
dinoflagellates (Picture courtesey of Ammonite Films).
You can find
more out about bioluminescence from dinoflagellates and other animals in the
ocean from following these links:
As most of the day was spent steaming, there was time to do other things like planning a student poster advising new students about seagoing and how to get involved. I had a look at some of the many interesting photos people have taken and was rather impressed by this quirky one.
It is the ship's radar screen when we were sampling station A, closest to Rockall. The 5 clear dots upper left on the screen are Rockall (not sure which one) and the 4 fishing vessels working there. Here is a picture of the rock with one of the vessels.
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