Monday, February 1, 2010

In the Eocene at 1000 meters below sea floor

We made it! After 1000 meters of drilling the microfossils indicate we are in the Eocene (more than 34 million years ago). Today the last bit of core was split and in the photo you can see the finger pointing at the piece that came from exactly 1000 meters below the seafloor. From the core we can tell that the sediment, which is very fine-grained clay, had been deposited quite gently particle by particle. It became a rock when cement had precipitated in the pores. Numerous burrows in the claystone tell us that the sea floor was once a lively place. The types of burrows, and the microfossils, tell us it was likely a deep marine environment, and that it was a greenhouse world. How much warmer it was here so close to Antarctica and how it got so cold as it is today is what we need to find out next through analyzing samples. Most of this work will be done when we get home. But the important part is done: get the rocks of the right age.

But it is not time to go home yet! Instead over the next few days we will move closer to Antarctica. The ice conditions have improved and one of the shelf drill sites on the Wilkes Land coast is free of ice. Now the drillers are pulling up all the drillpipe. We are in more than 4000 m of water, so that is 4000+1000=5000 m (15,000 ft) of pipe that is currently hanging below the ship, imagine that! The pipe is only several inches across, so it behaves like a string of cooked spaghetti. We are currently having high seas with waves up to 20ft (6m), so it is a real challenge for the drillers to pull it in.

I am really excited to wake up tomorrow and perhaps to see the icebergs and the sea ice. We may have to move slowly though because of the bad weather. After this one that we are currently in, a second storm is predicted to hit us. We have had snow today as well, and due to the strong wind and high seas it wasn't pleasant outside. Let's hope it will improve soon.

1 comment:

Anonymous said...

Nice post and this fill someone in on helped me alot in my college assignement. Say thank you you on your information.