Christmas on Castle Rock
3.5 miles from McMurdo station rises a rock spire known as Castle Rock. As a mountain climber I wanted to climb to the top of it.
There are safety rules for traveling out of the McMurdo area, so that I couldn't legally walk to the mountain by myself, even if other people did. So I gathered people who wanted to go with me, but, when it came time to actually climb the mountain they were busy working. Finally, on a sunny warm windless Christmas morning I decided to troll for companions.
Everyone is required to sign out for the climb at the firehouse so I sat outside and waited for over an hour. I began to wonder if there were any real mountain climbers in McMurdo. When at the crack of noon Claire and Lee showed up, they were off to climb. Of course, I realized, real mountaineers get a crack of noon start. I asked if I could join them and they acquiesced.
An ice color puzzle
We hiked up the dirt road out of town, passed the heavy shop, then explosive storage, and finally the road to the radar dome. Just as we came to the edge of the snowy ice there was a puddle on the road. Thin ice covered the puddle. The ice was colored. Claire thought there was an oil slick over the ice, and that is a good description of how it looked. Yet I knew what it was. I had them remove their polarized sunglasses and the colors went away. Polarized light from the blue sky was going through the ice, reflecting off the bottom of the ice crystals and returning through the ice on its way to our eyes. On its journey the polarized white light was broken up into different colors each with its own polarization by the birefringent ice crystals. Our polarized sunglasses allowed only some of the colors contained in the white light to pass through. Thus the ice appeared to be colored. Since I don't have a polarizer on my digital camera I couldn't photograph the colors in the puddle. (All our sunglasses were prescription glasses.)
At last we came to the windpacked snow with a line of flags reaching off toward Castle rock. Lee and Claire told me about Alaska, about snow fleas which I had seen before, and ice worms which I haven't. I showed them the neat frost feathers that grew in the shadowed parts of the footprints left by yesterday's hikers.
After a mile we came to one of the Apples, emergency shelters. If we got caught in a blizzard we could sit out the storm and call in our position on the VHF radio we were required to carry. I was also carrying the required large pack full of 25 pounds of ECW, emergency cold weather. The main danger on this day however was sunburn. We passed one more shelter after 2 miles then finally came to Castle Rock itself. On the scramble up amongst the brecciated boulders Claire noted black vesicular basalt chunks in the welded tuff. She also spotted a small patch of orange lichen, the first terrestrial life I had spotted in Antarctica. Later I looked up the geology of Castle Rock, it looked layered like sedimentary rock and also looked like a welded tuff. The geologists call it a hyaloclastite, which is a fancy word meaning that it was made by basalt lava erupting under ice (or water) the basalt was chemically altered by reacting with the water and became the reddish brown matrix imprisoning unaltered chunks of basalt. Hyaloclastites are forming today in Iceland where volcanos erupt under ice caps.
We made our way along the base of the cliff on the side nearest Erebus until we came to some easy ramps which lead up to the ridge. We scrambled up the ramps. Lee decided to rest in the warm sun while Claire and I headed to the summit.
We worked our way up to and then over the ridge. After climbing a little, we spotted a rope protecting a traverse across a gully full of rubble covered ice. It wasn't steep but a slip might lead to a long fall. Crossing the ice gully was the only third class portion of the ascent. (Third class to a climber means that you have to use your hands, in simpler terms it is a climb a human can do but a dog cannot. The climbing on Castle Rock is easy enough that some dogs could do it which makes it borderline third class.)
After the traverse we made our way straight to the summit. The views were spectacular. The summit plateau looked like it was in shadow, yet there were no clouds. Half of the summit was covered with black volcanic rocks which had weathered out of the tuff. As we sunbathed on the summit we could see the icebreaker 15 miles away. We could also see a parade of people following the trail to Castle Rock, the crack of afternoon climbers. Claire who is from Alaska called it the Chilkoot Trail, after a famous photograph of that trail covered with gold prospectors.
Claire saw a small dark cloud over McMurdo all the other clouds around the sky were light. Claire is a good observer. She wondered whether it was a pollution cloud. I smiled and told her to rotate her head to the side so that her eyes were on a vertical line. She gasped as the cloud went from dark to light. Once again the polarized glasses were responsible. The sky behind the cloud was polarized, viewed normally the sky was brighter than the cloud. Rotate the polarizer by rotating your eyes and the sky became darker than the cloud. So it wasn't a pollution cloud after all.
I sat on the summit enjoying the warmth of the sun on Christmas day, 2001. The new year was coming fast and with it new adventures.
We carefully climbed down, rejoined Lee, and headed back to McMurdo. All the way back we talked about trips and travels around the world.
Encounter with a strange sound
At one point I heard a strange swooshing noise, it kept growing louder as we walked. What was it, some sort of pump? No, it was running water. The day was so warm there was water running along next to the road, tumbling, bouncing and jumping its way down to the sea. The sound of running water made me remember what a strange place we are in, a place where liquid water is an unusual sight.
The miles went by quickly until it was time to check back in at the firehouse and head off to dinner. I was ravenous.
Return to Antarctica.
Return to Homepage
Scientific Explorations with Paul Doherty
27 Dec 2000