20 November, 1997

11/20/97

Thursday dawned with wind and not much snow blowing. It is time to go back to work after the storm yesterday. Most of the tents, however, were hard to see as they are covered with snow and a fog has moved in for a little while. Once back out at the clean air Jamesway, we find that a lot of snow has drifted and the trench we need to work in is covered over with snow and must be dug out. Large drifts are found everywhere, from camp to the Jamesway. It is easy to see how Sief dunes are formed. Sief dunes are extremely large sand dunes found in many places of the world. Some are like small mountains. The snow drifts here become huge and they could easily keep going if they are not walked on and knocked down by the graded. The people here at Siple Dome do a great job of grooming the skiway for the planes and around camp. Often you can hear them grading late at night and early in the morning. A skiway is like a runway for an airplane except the plane uses skis to set down with instead of wheels. The planes can land here as long as they can see us.

The drillers from PICO came out to the site today to start drilling core for Dr. Albert. She needed 15 meters of core to test the permeability of the snow. Permeability is finding the air spaces between the firn of the core. Ideally the deeper the core, the less space there should be between the firn crystals. The deeper and the less space between the firn gives the scientist and idea about the size of the firn crystal. Usually they are smaller with depth due to the compacting of the ice. The drillers brought with them a drill called a side winder that they could put into the ground and bring up the needed ice core.

Joey and I begin working on the core in late afternoon. We had to measure the cores, which should have come in about 1 meter long, than we cut them into 10 cm. lengths. We, then, placed them in a tube that is pressurized to form a tight fitting membrane about the core. Once this is in place we simple apply gas to the system allowing it to flow both on the outside and the inside of the core. The gas flow should be smooth called laminar in the core. Once we have adjusted the flow, we take readings and place them in a formula to find the permeability of the ice core. Darcyís law is used for this purpose from a spread sheet on the computer. The permeability are graphed according to depth and then Dr. Albert can analyze the data.