Tuesday, 30 March 2010

Whales, Ice, Penguins, Albatrosses - just the usual

We're well in to the science now and have completed the first set of CTDs - measuring temperature, salinity and oxygen down to just (10m) above the sea floor and collecting water on the way up (if the bottles seal, which they haven't been doing as well as they should) for carbon dioxide and trace gas measurements. The trace gases, especially CFC's, are a good tracer of recently formed bottom water that is sinking to the bottom of the ocean, taking some (about 40%) of our carbon dioxide emissions with it, as well as carbon that is part of the natural cycle. As there were no CFC's before we started making them about 50 years ago, if we find high concentrations at depth, then the water must have sunk recently. The water sinks due to getting very cold and also through increased salinity in the water left behind as sea ice forms - the ice itself is mostly fresh water. The average residence time of bottom water is about 1500 years so the water that is rising to replace the sinking water has carbon levels typical of 500AD, plus all the organic material that has decomposed into it, but that is more closely balanced by what is sinking now. We're currently having a break from CTDs to map a deep passage that we think most of the water is going through.

Swath screen giving the depth of the seabed - the beams extend about 55 degrees each side of the ship.

Anyway, enough science and on with the photos.

Me releasing a Kerguelen Petrel that had come onto the bridge wing overnight. Photo courtesy of Jo the doc.

Some preliminary entries into the unofficial airborne penguin photo competition - OK but to be improved on. Chinstrap Penguins often come and hang around the ship when we stop.

Grey-headed Albatross - beautiful bird but still trying for a good photo

Male Wandering Albatross

Nortern Giant Petrel playing in the ship's updrafts
White morph Southern Giant Petrel
Some icebergs

And the whales. Fin Whales put on an excellent show yesterday, relieving some of the tedium of the swath survey. A conservative estimate is that there were 50 in the two hour period, some coming close in towards the boat. The large swept back fin is the key identication feature. The right lower jaw is also pale (not sure why they have asymettric markings). There have also been a couple of Southern Right Whales but no photos yet.

They were regularly lunging feeding at the surface. One actually breached, which is very unusual for a Fin Whale.
One of several continuous shooting sequences:

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