Friday, January 15, 2010

A nice day with low seas

Today we had nice weather and relatively low seas. I was pleased to see a smile come back on the faces of some of my colleagues who had been sea sick for the last couple of days. We are now slowly drifting towards our work shifts from midnight to noon or noon to midnight (my shift). Once we are on site, expected for Monday evening January 18th, we are going to work around the clock and in two teams we will continuously process core.
The night-shift sedimentologists had a practice run today (see photo above). The two sedimentology teams will take care of visual core description, imaging, and color scanning. All information will be entered in a database. We, the day-shift team, had a practice run yesterday and we are now well-prepared for the first core on deck.
The palynologists are ready too: Joerg Pross and Peter Bijl. They are after the organic-walled cysts of fossil algae called dinoflagellates. These are microscopic photosynthesizing organisms that live in the surface of the ocean. Because these organisms evolved relatively fast, they are good biostratigraphic markers and give us an indication of the age of the rocks we are drilling. Joerg and Peter are working in a special fume hood in the chemistry lab, because they need to use a very strong acid (Hydrofluoric acid) to dissolve the rocks. This is the only way to obtain these microfossils that are so crucial to our studies.

This is really a time of getting everything ready: three more days and we will be on site. Today, I also saw a few people working on the drill rig. You could watch them work from the top of the bridge. The seas were too rough for work on the rig in the previous days. It is easy to forget how big the derrick is that we are carrying on top of the ship! Seeing the man out there puts it all in perspective.
The ice observer Diego Mello is expecting icebergs any time now, so he is watching the radar and the surface of the ocean. We are between 58 and 59 degrees South, which is where icebergs are rare, but easy to miss.

Besides the icebergs there is another interesting geological feature to talk about: we are crossing the boundary between the Indian-Australian plate and the Antarctic plate. The Indian-Australian plate carries part of New Zealand, Australia and India and the Antarctic plate carries the Antarctic continent. The plate boundary is called a divergent plate boundary, because the plates are spreading apart and new ocean crust is formed.
The plate boundary is expressed as a mid-oceanic ridge (indicated in green tints) and has multiple transform faults that intersect the plate margin at high angles. Due to the process of seafloor spreading, India and Australia are moving northward away from Antarctica. This process has been going on for some time. At our first drill, we are going to drill into rocks that are quite old and may date from the Eocene. During this time Antarctica and Australia were much closer than they are today, and if we go even further back in time both continents were part of a supercontinent called Gondwana.

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