March 5, 2006
Funded by the
National Science Foundation
Office of Polar Programs
Location: Latitude 63° 12' S, Longitude 56° 55' W
Air Temperature: 1.5°C
Today I woke up to the almost imperceptible rocking of the Palmer. I removed the pillows blocking the light from the window to be welcomed by yet another sunny day. As we headed out of the Drake Passage into the more sheltered waters of the South Shetland Islands and the Bransfield Strait, it has become smooth sailing. That, and many of us have gotten our sea legs. We are nearing the tip of the Antarctic Peninsula, which we will circumvent before entering the Erebus and Terror Gulf (not a name that inspires confidence; it is named after the two ships - HMS Erebus and HMS Terror - used by Sir James Clark Ross in 1842-43 to explore this area). The ETA to our first drill site is 3 am, where we will assess the ice conditions and conduct a multibeam survey before commencing drilling once the sun comes up. We expect to have a Kasten core on deck tomorrow morning!
Since we are still in transit, there isn't much going on. After lunch today, Andy Frazer, the drilling superintendent, delivered an explanatory talk about the drill rig and the different tools and bits that the drill crew can use depending on conditions, sediment type, and difficult drilling. I was amazed to discover that the drill rig on the Palmer was built specifically for this vessel and can be broken down (or demobilised) and stored in crates in Punta Arenas until SHALDRIL needs it again. Given the difficulties last year, Andy worked to design new bits specifically for the variety of sediments that he and his crew will be drilling though. Many hopes are riding high on a new diamond-impregnated bit (called The Alien), which Andy hopes can cope with soft sediment, till, and rocks. In order to drill, a bit (i.e., The Alien) is affixed to the bottom of the pipe string as the pipe is lowered to the ocean floor. Once there, it cannot be removed without pulling the entire pipe string. However, the inner drill bit can be changed in and out when needed by pulling it up the inside of the pipe string. The pipe string remains on the seafloor even though the ship bobs up and down due to a spring-like mechanism within the rig. My overall impression after Andy‚s talk is that the drillers have a lot of flexibility with the different tools and the ways in which they can be combined. My other impression is that the drill rig is a very very complex mechanism that takes years of experience to be able to operate smoothly. Luckily, we've got some of the best.
In the past hour, the ship has been coming upon some rather large icebergs and the view from the bridge is phenomenal! We expect to be seeing more soon (but hopefully not too many).
Andy Frazer explaining the drilling system.
Photo by Pat Manley.
Do you have questions? Comments?