US ITASE Logo

 

Date: 12/06/03
Latitude: 86.84 degrees South
Longitude: 95.31 degrees East
Temperature:−29°C(−20°F)
Wind speed: 15 knots
Wind Chill:−44°C(−47°F)
Wind direction: not given
Elevation: 10,250 feet
Kilometers traveled: 342

Notes on daily life:
By Dan

First thing this morning I showed the core dogs to Lynn and we decided to try and flip the core dogs 180 degrees as this prevented them from swiveling down too far. I dismantled the core dogs and replaced them in the new position; this was a fairly easy task because the metal of the inner core barrel was warm from being inside all night. But even working on warm equipment has its downside; any ice coring equipment that is to come into contact with snow or ice (which is virtually all of it) has to be cooled to well below the freezing point of water (0 degrees C) otherwise the snow will melt onto it, coating it with water, and then re–freeze and jam everything up. I took the warm inner core barrel outside and carefully placed it in the shade away from any snow and ice (the sun is so intense here that it can warm metal to above the freezing point of water).

After about an hour Lynn and I went out to try out the new core dog configuration. The new core dog position worked well in the soft surface snow but did not allow the sharp edge to really bite into the harder ice of the deeper layers. Back to the drawing board!

Meanwhile, Tom was digging a 2 m–deep snow pit so that he could sample the upper surface layers for isotopes at a high resolution. While Tom was doing working in his pit, Lynn and I took the inner core barrel back inside to warm up again. After some careful thought and consideration (plus some consultation with the drill manufacturer via satellite phone) we came to the conclusion that we were going to have to weld or braze a tiny piece of metal to the underside of each ice core dog to limit its travel. Welding is difficult at the best of times, and the smaller the piece of metal you are welding onto the higher the chance of it melting (the core dogs are less than 1 cm by 1 cm by 1 cm in size!). Luckily Lynn is an expert at welding and brazing as well as being a pro mechanic and we soon had bottles of oxygen and acetylene hooked up and ready to go. We prepared each core dog and after some micro–surgery with the welder and file were ready to try the drill again. I took the inner barrel outside to cool down again and prepared the rest of the drill for another test run. After dinner, when the inner barrel had cooled enough, Lynn and I set about test drilling for the third time. This time drilling was a complete success and the core dogs did not drop a single piece of core, although we did get quite a few hangers–on in the soft upper layers (a hanger–on is a piece of core that slips past the core dogs a little way before they bite and ends up protruding out of the end of the barrel). We drilled down several meters to be sure that everything was working perfectly and when we were satisfied I recruited Tom back onto the drill team ready to begin drilling the chemistry core (by now it was 22:00). Unfortunately, there are several science projects relying on the success of this traverse and as a result we are on a tight schedule. Matt wanted to be underway by noon the following day so Tom and I prepared ourselves to drill through the night. We donned our Tyvek suits, masks, and plastic gloves and began to section the top 2.5 m into 2 cm slices. We put each 2 cm chunk into its own bag and then seal and label it (we do this because the soft upper layers would never survive the journey back to the states without crumbling apart), it is a long and laborious process and you get very cold because there is not much movement or activity involved. We had to retreat inside to the warmth of the kitchen module several times during the sectioning process.

To be continued.

Date: 12/07/03
Latitude: 86.21 degrees South
Longitude: 95.75 degrees East
Temperature:−27°C(−17°F)
Wind speed: 10 knots
Wind Chill:−39°C(−38°F)
Wind direction: not given
Elevation: 10,440 feet
Kilometers traveled: 413

Notes on daily life:
By Dan

At 3:00 am we had finished the sectioning and were ready to drill in earnest. By about 6:30 am we had reached approximately 10 m depth and then we had a surprise visit. Lynn had woken up and come out to help. Tom and I were very grateful for Lynn’s help because the whole drilling process goes twice as fast with three people and we were fast running out of drilling time. By the time noon came around we had reached 18 m depth, I had a word with Matt and he agreed to let us drill for another hour. At 13:00 we finished up and started packing away the drill rig ready for travel. We had drilled a grand total of 21 m, it was not quite as much as the planned total of 30 m but I think that under the circumstances we did very well. I must thank Lynn for his astounding welding and brazing skills and Tom for braving the cold wind and working throughout the night with me.

By 15:00 we had all the sleds strapped down and ready to travel. As we started to move I fell into my bunk and slept until midnight (I slept through dinner which wasn’t surprising considering that I had only about 4 hours sleep during the last 57 hours). When I woke up I found out that we had traveled 71 km during the last two driving shifts and hadn’t gotten stuck once. This is a new LGT record! I got dressed up in my warm clothes, went out to collect some surface snow samples, took some photos, and then went back to bed.