JC24: Dating volcanoes on the Mid-Atlantic Ridge


Cruise diary

Sunday 1 June 2008

Isis is neutrally buoyant (meaning it neither floats nor sinks in water) because this makes it easy to drive it around the sea floor without it sinking down and hitting the bottom or continually trying to rise to the surface. To allow for sampling, this neural buoyancy includes a certain allocation (56kg) for rock samples, which is accommodated on the descent by weights placed in the baskets, which are then swapped for rocks on the sea bottom. Unfortunately a severe case of ‘sample fever’ appears to have hit the scientists over the last 24 hours, resulting in us having reached, and indeed massively exceeded, our payload limit (the amount of weight we are allowed in rocks) having only travelled a third of the way along our first dive.

As one of the cruises major objectives is to sample the AVR it was decided it was worth loosing 5 hours to recover Isis, remove the samples and re-deploy it, rather than continuing along the dive track and not sampling. As a result, at 2:30am it was decided to bring Isis back to the surface.

Processing the samples is a big job as all samples must be brought in, placed in sample  bags, labelled with their sample number, then weighed, photographed and described. Next, the glass from the outside (used for dating the rocks and analysing their chemical characteristics) is chipped off. Finally, the rocks are cut into slices and everything is labelled again and put away.

Isis was deployed again at breakfast time from the other end of our dive track. More on our first dive tomorrow!

Bringing Isis back on board

Chris prepares to receive the samples

Isobel and Kirsty model sample collection chic

Bram begins to process our 25 massive samples

< Previous day | Next day >

Home -



Latest news

For teachers
Contact us

May 2008