21 December, 2002

A busy day at Site 3

Date: 12/21/02

Latitude: 85° 00’ 01.57” S

Longitude: 104° 59’ 42.57” W

Time of Observations: 10:00 p.m. local time

Temperature: -25 C / -13 F

Wind speed: 5 knots

Wind Chill: -33 C/ -27 F

Wind direction: Northerly

Meters of ice collected: 383 m

By Paul Andrew Mayewski

Today is our second full day of work at Site 3. As with all of our sites there is a great flurry of scientific activity. Brian and Carl went out on a 50 km traverse around our site to map ice depths. We are camped at the lower reaches of what is called the “Bottleneck”. It is the transition between West and East Antarctica and is of great importance to our understanding of the ice dynamics and the mass balance of the total Antarctic Ice Sheet. One of our colleagues back at the University of Maine, Terry Hughes, named the Bottleneck. He suggested that if we can understand ice flow through this region we will be able to better understand the past history and perhaps better predict the future of volume change over the ice sheet. Volume change of the Antarctic Ice Sheet is closely linked to global sea level change as described in a log yesterday by Blue Spikes. Upon return Brian and Carl told us that we are camped on the side of a large subglacial valley this valley is no doubt the or one of the major channels for ice flow between West and East Antarctica.

Many other experiments were also in progress today. Markus and Betsy launched a tethered balloon to study temperature and ozone concentrations up to 1 km above the camp. They also did on site measurements of selected chemistry in the near surface snow and air. Gordon and Blue, later assisted by Jim went 1.5 km off from camp to emplace GPS markers to monitor ice surface displacement. Dan, Susan, Mark and Paul worked with the 3” drill to collect a 45 m deep ice core. Based on chemical measurements at the site by Markus and physical observations by Paul the 45 m core is expected to provide a 300 year record. The 3” drill crew worked pretty late into the evening because of a generator malfunction that prevented drilling for several hours. Lynn identified the problem as a fault in the oil level sensor.

During all of the scientific experiments Lynn and Carl prepared the camp for our next leg of travel to Site 4. They modified generators to tolerate the higher altitudes and lower oxygen content we will soon encounter. They also modified the solar power system in the kitchen. The original 3000 watt system failed a few days ago so they borrowed the 1800 watt system from the Polar Haven, where Lynn, Carl, Mark, and Paul sleep, to power the kitchen. This is largely a back up in case the Blue Room power should encounter difficulties. The Blue Room power source is needed for our shallow radar experiments en route. All the while Andrea is preparing meals that we look forward to, and keeping the food stores in shape.

Tomorrow we will complete our work at Site 3 and then off to Site 4 (Hercules Dome). Once at Hercules Dome we will have truly entered East Antarctica. I will certainly be happy, because in many ways stepping foot onto East Antarctica will have taken us almost four field seasons and close to 4500 km of travel. Once the ice core climate records are developed we hope to be able to understand differences in climate between West and East Antarctica and change in climate over time. West Antarctic climate is closely related to the climate of the Pacific Ocean. East Antarctic climate is dominated by the intensely cold, dry air masses that descend over the center of East Antarctica from aloft. The climate transition between Pacific climate influences (including El Niño) and interior East Antarctic climate may well be captured in the region of the Bottleneck. Imagine standing at a place where you might be able to monitor the interaction of such immense climate systems.

The Bottleneck is a real crossroad for us. It is the transition between East and West Antarctic climate and ice flow. It is also poses the steepest gradients we will encounter during our traverse to the Pole. We pushed up over about half of the Bottleneck gradient jump in our travel from Site 2 to Site 3. Soon we will experience the next jump from Site 3 to Site 4. Once at Site 4 (Hercules Dome) we will be close to the elevation of South Pole. As we leave Site 3 tomorrow we will be more than half way through our scientific goals and our traverse.