Sunday, October 14, 2007
The science behind the drilling
We spent the last two days getting ready for core and getting our lab set up. In addition: most of us are working on a series of lectures that we are going to present to a group of teachers who are here on ice for the public outreach component of our project. Tomorrow night the first core is expected. The sea riser (the outer pipe of the drill system) is cemented in the sea floor and the PQ drill string (the inner pipe) is now drilling into the sea floor. We use a similar type of drilling as in the middle example of the figure to the right. The drill rig is mounted on the sea ice (~ 7 m thick), and drills into the sea floor in a water depth of ~ 400 m. We are drilling at this location, because we have a unique geological setting here with a rift basin which is filled up with sediment and preserves a record of glaciation back in time. Over the past millions of years layers of sediment have been piling up in the graben. By drilling into those sediments we can reconstruct the climate and glacial conditions in this area back in time. The layers have a different character depending on whether they were supplied by glaciers, or rivers, for example. Our drillsite in the diagram to the left is located at the red triangle closest to the volcano Mt. Morning (M). We hope to drill ~17 million years back in time.
Posted by Sandra Passchier at 1:48 AM