19 December, 1998

Good morning from Beacon Valley!!

Today we had leftover steak, potato and corn for breakfast. We got on our packs and were ready to leave around 9 am. We went up valley today where Drew will be working.

My knees are swollen like grapefruits today. I just have old knees, but I know that I will be the slowest today. I am going to be slowing them up and this won't be well received by my camp mates. I will do my best.

There is an unbelievable jumble of rock sizes - from the size of a Cadillac to thumbnail. We saw many perched boulders and other piles of rock. Did these rocks come out of the glacier or fall from the sides of the valley?

We watched Hallet's group from the University of Washington come in via helicopter around 11 am. They will be camped near us, about a kilometer away. I now know that there is going to be quite a bit of tension with them camped so close to us.

In the afternoon while we were up valley Adam and Drew noticed small surface cracks or wedges. Being curious, they shovel and pick down about a meter and a half and the wedge just goes all the way down. Dave and Eric get one that looks like a big Tootsie Roll which is also associated with a wedge.

Could it be that these are thermally generated?

Drew and Adam dig an amazingly deep pit, about shoulder height - it's christened DME-05-98 (Dave Marchant excavation number 5, 1998) This designation is written on a canvas rock bag and appears in the photographs of the pit. Photographic documentation is important - it is another line of evidence used to give support to a hypothesis.

Using the ice axe, they sample ice from pit number 5 to analyze 18O/16O ratio. Water molecules with the light 16O isotope evaporate more easily than molecules with 18O. Therefore, 18O is enriched in the oceans (and the shells of marine animals) during glaciations. Less 18O is therefore available to fall as snow or rain. Consequently, the 18O/16O ratio ratio graph based on fossil shells records glacials, but also interglacials, and smaller variations in global glacier ice volume. The ages are correlated, based on direct radiometric dated events on land and dates from organic remains in core.

The ice is placed in small plastic sample bag, labeled and then buried in a snow bank. We bury the samples in the conviently located nearby permanent snowbank. We dig holes in the snow and then after we bury the samples, we pile large blocks of snow on top of them. This will insure that the samples remain frozen.

Samples of modern snow were also collected as a control.

Today was another windy day, much snow is blowing into Beacon from the plateau.

It is a powerful feeling to look to the south and know that just over the ridge is this plateau, that the pole is South. I think of fellow teachers Elke Bergholz and Sue Bowman every time that I look in that direction.

Bye from Beacon

Hillary

Hillary Tulley

Niles North High School

9800 Lawler

Skokie, IL 60077

847.568.3292 office

847.568.3166 fax