April 29 2008
April 29 2008
Tina van de Flierdt chiseling off the ferromanganese coating from some of the rocks from the dredge.
Today was just a perfect day – blue sky, lots of icebergs, and an absolutely calm sea. Nearly everybody took the opportunity to go for a little walk on deck. The view from the bridge was simply stunning. It was a shame that the daylight ended again at 4 pm. We are now far enough east that the fact that we stayed on Chilean time (this is our ship time) means that it gets dark very early. This way people on the day shift (noon to midnight) see actually less daylight than the people on the night shift (midnight to noon).
On the science side all the surveying starts to pay out big time. We had our first successful dredge to retrieve in-situ samples from the bottom of the Scotia Sea. Recovery of this dredge was quite dramatic, as we got stuck with our metal net at the bottom of the ocean. The captain did an incredible job in moving the ship back and forth to break the net loose. Finally he won the battle and the rocks could be lifted aboard.
The surprise of the day was however that half of our ‘catch’ was made up by ferromanganese nodules. These dark brown to black and round objects can be found in many locations of the ocean floor. Nobody knows exactly how they form, but they are made up by iron and manganese oxides and oxyhydrides that form from ambient seawater. When cutting open such nodules, one will find that they look like trees with their individual growth layers. In nodules, however, these growth layers are not annual but rather represent thousands to millions of years. Therefore they are very valuable archives of the seawater chemistry back in time.
Tina van de Flierdt
All photos by Dann Blackwood unless otherwise stated
Many ferromanganese nodules and rocks were brought up by the trawl.
Many ferromanganese nodules and rocks were brought up by the trawl.
John Swartz shows the disadvantages of working with ferromanganese nodules.
One of the ship’s crew repainting the deck.
The dredge being deployed by MT’s Greg Buikema and Zim Zimmerman.
Some of the midday to midnight crowd out on deck enjoying the beautiful sunshine today.
Some of the icebergs play home to penguin colonies.
Chinstrap penguins swam along side the ship for a few minutes.