Day 16 More mud

Fred taking water samples from the CTD

Sampling sediments from the box corer

Albatrosses and giant petrels around the ship

Black-browed albatrosses

The bad weather and high seas of the last few days seem finally behind us. The violent jolting and heaving of the ship as it rolls and pitches are replaced with a gentle rocking motion. The sun came out this morning and the ocean looks friendly again. We are at about 130 miles to the west of the Willis Islands on the westernmost tip of South Georgia, a British Overseas Territory constructed almost entirely from rock, ice, birds and seals. I hope to find out more about the island, as we're due to call at the base in King Edward Point (the capital of South Georgia) some time next week.

During the night, one of the science teams was up and watched the data on the multi-beam swath and on the TOPAS (sub-bottom profiler). The paleo team is surveying the area for suitable coring sites. That's places were sediments have accumulated on the sea floor to give clues to the climate in our geological past. So at night they survey the area and then decide in the morning on the best site for coring. The physical team was first to deploy a CTD. The photo above shows me taking water samples from the CTD. The salinity samples are used for calibration that I wrote about a few days ago.

We then deployed the box corer. This gives a good clue to the consistency of the first few inches of the sea bed. The box corer is a metal crate where the bottom is initially open, but upon contact with the sea bed snaps shut like a giant mousetrap. The mud on the sea floor looked very promising - we got a big box of lovely diatom ooze. Diatom are single-celled microscopic algae. They are the beginning of the food chain in the ocean - a chain that starts by photosynthesizing sunlight into energy, which can then be eaten by other organisms. The fact that they're a kind of algae makes them basically plants, and even after millions of cells had died and settled on the sea bed, the ooze still looked slightly green.

Next up was the gravity corer - a long metal tube lined with plastic which can penetrate into soft muddy sediments for many metres and retrieve layers of dead organisms deposited thousands of years ago. Did I say it works well on "soft" sediments? Well, yes that's the idea. And that's why we take a look with the sturdy box corer first to make sure it's not bedrock under the ship. The gravity corer did indeed find soft sediments, but after about a metre or so it hit solid rock which badly damaged one of the metal tube sections. Thankfully the team brough plenty of spares and the coring tube can be repaired for tomorrow. But this section of the Scotia Ridge west of South Georgia is out of bounds for coring for the time being. Let's hope tomorrow's site will yield a deeper and softer sediment layer.

With the improved weather conditions, the wild life has returned to the ship too. We are now being trailed by hundreds of petrels, prions and albatrosses. The most impressive bird of them all is the Wandering Albatross. He is surely the king of the Southern Ocean - its wing span can reach over 3 metres! Seeing several wanderers glide past the ship, riding its updraft and skimming the waves is a truly magical experience. The photo above shows a pair of black-browed albatrosses, which are smaller but still exquisitely beautiful. I am still trying to get a good photo of a wanderer in flight.
Watch this space...