John Oliver writes:

24 October 02 Thursday

Today the entire group (all 6 of us) made our first dives at Cinder Cones, which is about 10 miles north of McMurdo Station. We had so much gear that four of us took skidoos, and only the two oldest rode in the Piston Bully, our tremendously cool and useful tractor. Big Dan and Stacy fell off their skidoo, but recovered with no injuries. The sea ice is hard! Because the ice is two years old, the surface is very rough- lots of low ridges and holes. Last summer was extremely warm and the ice surface melted into complex patches of melt ponds and high spots. As the weather cooled, this uneven surface froze and that's what we drive on. The dive hut was warm, and has a hole in it for access to the ice hole, which wasn't even frozen over. The holes outside had a 4 inch layer of ice covered by blowing snow. Snow is a great insulator and prevents the ice from freezing as thick as it could. The water is only -0.2 degrees centigrade. The air is -20 without the wind, and much colder when the wind blows.

We dressed in warm comfort, occasionally opening to the door so we wouldn't sweat in our thick underwear and dry suits. The bottom slopes gently to about 20 feet, then steeply to over 100 feet, and then gently again for as far as we can wander and see (many hundreds of feet). Cinder Cones has a well developed wave-cut bench from 20 feet to the land. This area is still covered with ice growing on the bottom (anchor ice), and harbors very few animals. The bottom area below the heavy anchor ice region is covered with a dense community of polychaete worms and many other invertebrates living in the sediment (benthic infauna). Much larger sea stars, sea urchins, and nemertean worms (called megafauna) are extremely abundant and move on the surface of the sea floor containing this dense infaunal community.

We took samples of the infauna using cores that collect a standard area of the bottom (quantitative samples); sediment for measuring physical and chemical habitat features; counts of large infaunal clams whose siphons can be seen at the sediment surface; and photographs and videos of larger bottom areas so we can count the megafauna (at home in a warm room!). We also relocated experiments that were started in the 1970's by Paul Dayton and John Oliver, and others started in the early 1990's by Hunter Lenihan, Stacy Kim, Cathy Conlan, and John.

Then we dug sediment, placed it into 5 gallon buckets, attached the buckets to a rope, and hauled them up and into the dive hut. We collected 8 buckets of sediment from three marked sites that will be used for other experiments. We brought the buckets of sediment back to the lab where we will eventually add organic material to half and leave the other half for controls (no food added). We'll talk more about these experiments as they are prepared in the lab and established in the field. We went to bed tired, but much further along in Stacy's schedule.