JC010: Mud volcanoes and submarine canyons


Cruise diary

Day 6: Tuesday 26 June 2007
Position: 39°29.712N 09°55.984W (Google Earth reference: 39 29’7”N 09 55’9”W)
Weather: Sunny with light cloud

Tina writes:

"When I was told today that a probe was being sent down to collect data on temperature, density and salinity I had a good idea what they meant - after all, I use probes quite often in the classroom testing the temperature or pH during experiments.  So when I went outside to have a look at what was going on I expected to see a probe, bigger than one I would normally use, about the size of a large video camera. Wrong!  The CTD probe is as tall as me and needed a crane to lift it.

Left: The CTD (Conductivity - Temperature - Depth) probe being deployed

This isn’t the only thing that has surprised me so far.  Others are:

How often I have to change:
I wear jumper and shorts in the general lab (it has very effective air conditioning!); steel capped boots and a hard hat while on deck (safety gear, they are hot on this on the ship); arctic weather gear when in the cold lab – kept at about 4oC, the temperature of the deep sea to keep flora and fauna alive as long as possible; overalls and safety boots when processing the cores and t-shirt and shorts in the ROV control van as its quite warm in there.  So far I haven’t had to put on my wet weather gear, but I have it waiting...after all it is the SW Approaches next!

How many steps I climb each day:
It is 14 steps to the labs and deck, 28 to the canteen and 78 to the bridge.  So by the end of the day I have had quite a work out just getting around.

How fat I am getting:
Its been said before and I must say it again, the food is good - I would not be surprised if they have to roll me off this ship.

How much more there is to discover:
I have spent the last few days trying to work out what is on the ship and what it does, every day I discover more equipment.  Today I went up to the bridge and spotted two cranes I hadn’t noticed before.

Today we:
Sent down the Megacorer
Sent down the CTD probe
Sent down the SAPS (Stand Alone Pumping System)..."

Richard writes:

"Coring took place for one last time in Portuguese waters before we steam towards the Irish margin later on today. I helped Wouter to slice cores so that Jeroen would have more samples to carry on with his research on deep sea nematodes (microscopic worms) and their food chains. The processing was carried out in the Controlled Temperature Laboratory at 4ºC so as to keep the environment as close as possible to the natural environment of the nematodes: don’t forget they live at the bottom of the ocean which is constantly around this temperature. The cores also contain sea water just until they are cut, again to disturb the nematodes as little as possible. The conditions in the lab were far enough from our natural environment to make us very cold though!

Left: cores ready for sampling

There were 2 types of processing here:

Normal cutting’, much like the type described in processing push cores, although the samples were stored in Petri dishes (plastic containers) after cutting, with no further processing. Jeroen is also interested in analysing different depths of sediment to that described, so the slices were 0-1cm, 1-2cm, 2-3cm, 3-4cm and 4-5cm.

Processing for quantitative analysis. You may have guessed that this has something to do with numbers, and you’d be correct – the quantitative fauna analysis helps to put Jeroen’s other experiments in context by revealing the total numbers of animal species, and the total numbers of each species present in the sediment. The processing involved using filtered seawater to rinse every last grain of sediment of the ‘cuts’ into little plastic jars – the animals are so small that leaving out the tiniest bit may have a big affect on the results as you would count too few animals. It is important to use filtered seawater so as not to introduce organisms which may already live in the water and would therefore make the results inaccurate as you would then be counting more animals than there should be. These samples were then ‘fixed’ (which basically means preserved) with formalin, and so can be kept for a long time before you analyse them and they will still give accurate results.

Right: Wouter opening a core - chilly work!

I also had a chance to find out a little more about Wouter’s own research interests. He is carrying out research on the distribution of macrobenthos species in the North Sea. Macrobenthos are species larger than 1 mm, living in the sand, like worms and clams. He uses computer models to determine which habitat is suitable for a species, for example, which is the right sediment, the right depth and the best temperature. After this he will be constructing maps showing the distribution of the species."


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