19 October, 1997

19 October 97

Dr. Adam Marsh, Dr. Rob Maxson, and myself went on a field excursion to Cape Evans today. Several other divers joined us at the dive site. We needed to collect sea urchins so that we could spawn them and begin some cultures. Dr. Maxson has very limited time here and has been anxious to begin his studies on RNA turnover.

I'm becoming more and more familiar with the landmarks here and feel comfortable out on the ice. Dr. Marsh suggested that I become certified to drive the Sprytes (the track vehicles we use for transportation on the ice). I'm looking forward to that and would enjoy navigating the Spryte on some of our field excursions.

It was quite an experience to watch the divers. The dive hut is located at a site next to an iceberg which broke away from the Mt. Erebus glacier tongue years ago. Apparently it has floated out to sea once or twice but keeps returning. It is now grounded and frozen in the ice just off Cape Evans. It makes quite an impression while standing on the sea ice looking up at its massive structure. It has vertical walls which rise 75 - 80 feet out of the sea ice. The colors are spectacular and will vary from white to aqua to white to blue. The neatest thing about the iceberg is the view from inside the dive hut. The water is crystal clear and if you stand at the proper angle you can see the underwater portion of the iceberg all the way to the bottom. The divers spent a lot of time exploring around the base of the iceberg. New ice crystals have formed and organisms have colonized these areas. The iceberg has become a new community of amazing beauty.

When we first arrived at the dive site and entered the hut we found that a jellyfish had come to the surface and was greeting us through the hole in the ice. One of the divers was there specifically to collect jellyfish so naturally he quickly gathered it up in a bucket. During the afternoon a large variety of sea life was collected and photographed. One of the divers was Dr. Kathleen Conlan from the Canadian Museum of Nature in Ottawa, Ontario. She was videotaping the dives for the museum in Canada and agreed to provide me with a copy when she returned. I am greatly looking forward to taking her up on her offer.

Some of the divers suggested a way that I could get a sense of what it was like under the ice. I simply put on a pair of goggles and stuck my head into the dive hole. The view I had was breathtaking. I was able to see the iceberg and the community of marine life on the bottom. I watched until my face became numb in the minus 1.4 degree Celsius water then did it several more times.

When we left Cape Evans we made a stop at Little Razorback Island to refuel the fuel tanks for the stove which heats the dive hut. A giant Weddell Seal had come up onto the ice through a pressure crack. She had apparently just given birth to a pup. The surrounding ice was quite bloody and at first I thought the seal had been injured. We watched for awhile as the seal pup got oriented to its new world and began nursing from its mother There was plenty for me to think about on the trip back to McMurdo. It had been a memorable day.

Things to ponder:

1. Why do glaciers form?

2. How do icebergs form? Does an iceberg taste salty like the ocean?

3. What is the fate of every iceberg?

4. Why do you think baby seals are born on the ice (or land) instead of in the water?

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