Tuesday, 26 March 2013

Day 12 - The Antarctic Shelf...at last!

There is something exciting about throwing an expensive piece of kit over the side and hoping it comes back. Emboldened by the previous day’s success and a further calming of the weather, we continue to deploy the VMP and measure turbulence rates. It is quite fun for most of us (well, for those of us whose kit it isn’t…). When at the surface, it begins pinging signals back and forth. We all run to the main bridge and look out for a little fluorescent flag and a flashing light. Sometimes a bird, hoping it has just found a feed, helps us out. Then we have the fun job of hooking the floating instrument as it passes by. It is a bit like a combination of jousting and fishing.


 Photo: Gwen the scientists and much of the crew's eyes are in demand.

 Photo:  "Hey! You're not an Albatross"

 Photo: Gwyn and James go fishing for VMPs

We have only been at see 9 days, but for the CTD crew, the monotony is beginning to wear:

Get up
Chat to Brian at the end of his red-eye shift
Grab a quick breakfast before his CTD comes on board
Take water samples from the bottles
Prepare the CTD for the next deployment
Steam 20 miles to next site
Check meteorological and ongoing measurements
Process some data
Get to station
Put CTD in water
Lower to bottom – raise to top
Take CTD out of water

I am sure it isn’t any easier for the chemists:
Take water from bottle
Poor water into machine that goes ping
Write down reading
Take water from bottle

Today however we are close to a major milestone, we have reached the base of the Antarctic Continental Shelf. This is where the ocean depth goes from very deep (like 3-4km) to very shallow (like 100m-200m). It signals the end of this ‘Section’ and means we will have soon gathered enough data to estimate the strength of the Circumpolar Current. Hopefully by the morning we will be in the shallows and heading east to see if the ice has frozen over our moorings. And, if it has, there will be lots of pretty icebergs, seals and penguins to look at…stay tuned.

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