Ice Cores from the Dry Valleys October 2003

Ice Cores from the Dry Valleys of Antarctica

Karl Kreutz, Bruce Williamson, Erich Osterberg
October 18, 2003 to December 10, 2003

October 23, October 25, October 27, October 29, October 30, 31, Nov. 1, 2, November 27, 2003
In the field: Day 6-10, Day 11-15, Day 16-21

Friday November 7, 2003

click on a photo to see it full size

Day 1
Weather: Cloudy with southerly wind at McMurdo, cloudy and calm at Clark.
Temps: 10-15° F
Ice collected: 0 m

We arrived at the Clark Glacier via Bell 212 helicopter at 10 am. Took a total of 4 helicopter loads to transfer all of our gear and 4 passengers to the glacier. Each helo trip included a sling load where gear was carried in a net below in addition to filling the inside of the helo. All together, we have ~5000 lbs of gear, the majority of which is science gear including the radar and coring equipment.

The Clark glacier is a beautiful spot with mountains to the south and to the north, and we can see all the way to Mt. Erebus – the active volcano on Ross Island near McMurdo station.

We set-up our camp with three tents. We have two Scott tents, which are yellow pyramids with vents at the top so you can operate a stove inside. Each Scott tent sleeps two people very comfortably. The third tent is a red, blue and yellow Endurance tent, which we use for the kitchen/living room tent. We have two stoves in the kitchen tent and one each in the Scott tents (for heat + cooking in storms). The fifth person will sleep in the Endurance tent. For sleeping, we each have a small army-style cot, an air pad, a foam pad, a fleece sleeping bag liner, and a sleeping bag rated to -50ºC. Very comfy! Mike made a small igloo for a freezer for our food, and we also made a snow toilet. Camp was set-up by evening and we broke for dinner. After dinner, Karl and Mike began checking for crevasses around camp and staking flags for the radar lines.

Saturday November 8, 2003

Day 2
Weather: Sunny and beautiful, afternoon southerly breeze
Temp: ˜10°F
Ice collected: 2 m

We spent all day digging a 2 m-deep snowpit and collecting snow samples from the wall of the pit. The samples we collected will be analyzed for major ion concentrations, trace metal concentrations, and stable oxygen and hydrogen isotope ratios back at UMaine. We also measured snow density and temperature throughout the sampling wall. When we sample, we have to wear special white suits that are very clean and do not leave any lint behind so that the samples do not get contaminated. We also use specially cleaned tools and bottles. We did not finish sampling until 10:45 pm.

Steve Arcone, the geophysicist who will operate the radar, arrived via helicopter at 1:30 pm. He came 1 day late because he had to finish his snow school. Steve set-up his gear and he began to run some radar survey lines with our help. The radar computer was set-up in an insulated black box on a sled with a generator for power. The radar transducer and receiver were dragged ˜20 feet behind the main sled in a separate sled. To collect the radar data, we had to pull the radar sleds along the survey lines at a constant speed. It was a tough job for 2 people, but with 4 people pulling it was not too hard. Each survey line was between ˜500 m and ˜2 km (1/4 mile to 1 mile), and red flags were placed every 100 m so that Steve could mark the radar record as we passed each flag. There were usually 4 survey lines on each glacier, and Steve usually wanted 2-4 radar surveys along each line, so we pulled that radar sled a long way over the entire 3 weeks!

Sunday November 9, 2003

Day 3
Weather: Sunny all day, strong southerly wind in afternoon (cold)
Temps: teens
Ice collected: 2 m

Radar survey all day – lots of man-hauling! Steve is very excited by the results. We are able to see all the way through the ice down to the bedrock below – total ice thickness is about 280 m (920 feet) – Steve has never been able to see this deep before. We are also able to see internal layers in the ice that shows us that the Clark is a very good site for ice coring.

Monday November 10, 2003

Day 4
Weather: Cloudy in morning, clearing all day. Light southerly breeze
Temps: Teens
Ice collected: 14.5 m

Karl, Mike and Bruce drilled the ice core with a hand auger drill from the bottom of the 2 m snowpit and reached a total of 14.5 m deep. Drilling took almost all day. Steve and Erich helped drill in the morning, and then completed the first global positioning system (GPS) survey along the radar survey lines. The GPS uses satellites to give us very accurate positions for all of the red flags along the radar lines so that we can make accurate maps of the glacier when we are back in Maine. Unfortunately, the satellite coverage in Antarctica is not as good as it is in Maine, so we had to stop the GPS survey periodically to wait for more satellites to move overhead. To pass the time as they waited, Steve and Erich resorted to yoga, push-ups, and even a few games of chess in the snow with pieces made out of duct tape. The GPS antenna was mounted on the same sled that we used for the radar survey. Without the generator and heavy computer from the radar, the sled was much lighter, so it was much easier for Steve and Erich to pull it around the glacier.

Tuesday November 11, 2003

Day 5
Weather: Mostly clear in the morning with fog rolling in at ~1 pm. Calm.
Temps: Teens
Ice collected: 14.5 m

We did a second GPS survey and finished that off by late afternoon – a long day of hauling. Karl and Mike installed several aluminum poles into the glacier that we will use to measure how much snow falls in one year. They measured the distance from the top of the pole to the snow surface and marked it on the pole. Next year we will return to the poles and re-measure the distance to the snow surface.