About half an hour from my house back in California there’s Castle Rock State Park, named for a big sandstone formation which is popular with rock climbers. I’ve hiked there a lot and even built and helped to plan trails for the park. It’s a large park in the Santa Cruz mountains, with enormous old redwood and douglas fir trees, strange sandstone formations, ridges with great views, and canyons with great creeks.

Well, today I went for a hike on the Castle Rock loop, but it wasn’t the standard hike. McMurdo has its own trail system, which isn’t too surprising considering that a lot of the people I have met here have a big interest in the outdoors. There are about five general trails here, but a few variations on some of them. One of the most popular is Observation Hill, which most everyone in town has climbed. It’s a very prominent volcanic cone just on the edge of town, and the views from the top are spectacular in good weather. A cross erected on the top commemorates Robert Scott’s South Pole expedition, which achieved the South Pole but died on the return journey.

There’s also a loop around the hill, which got a little attention a week ago with the second annual Trail Daze. I joined the trail crews last Sunday and helped to clear snow from the loop. With the side slope there, the snow made the hike kind of dangerous, but it’s much safer now with the work we put in. Another crew worked on the Hut Point Loop on the other side of town. I have yet to hike that loop, but will do that before I leave.

Hiking here in Antarctica is a little different from other places. Some of the trails, especially the Castle Rock loop, require that you check out with the fire station in town, carry a radio with you, and not travel by yourself. Saturday night I had asked everyone in the group if they wanted to hike the Castle Rock loop and Francois said that he’d like to go. DJ was unsure, since he has a lot of work to do before he leaves, but he was going to try. Others in the group were busy with getting ready for the helicopter flights to Heald Island on Tuesday, or with other stuff. Fortunately DJ was able to make it and two other people that Francois knew joined us for the hike.

The weather was spectacular as we headed out of town. Stacy had sent us off with a huge load of food (which we barely ate) and we checked out with the fire station. The start of the hike wasn’t very interesting as it wound through town, but we soon started climbing out of town. The hill we climbed holds a lot of storage – old vehicles, science experiments and all the food waste from the station. The waste is packed up in a huge pile of triwall containers (really thick cardboard) marked simply “FW”.

Even a little further we passed the explosive storage for the station. Surpirsingly, we’re not allowed to walk through that area. We soon made it to the trailhead, which had some unusual (for most of the world) warnings, and started the real hike.

In general, most of the early part of the hike was gaining a ridge that runs roughly northeast on Ross Island. Once we gained the ridge we had views to both sides of the peninsula, looking out onto miles and miles of sea ice. It’s difficult to take pictures here with all the light reflecting off such white surfaces (and also because I’m not an experienced photographer).

Along the route there are three emergency shelters. These are placed in case bad weather or some other problem strikes hikers, skiers, snowmobilers or other travelers. They’ve got emergency gear, some extra food, and a phone. We actually used the phone in one of them to call the lab and see how the packing was going. Two of the shelters are called “apples” because they’re bright red. I’m not sure exactly what they’re made of – probably some fiberglass with a little bit of insulation blown in. Doesn’t really help too much if the wind blows a ton of snow in through various holes, though. Still, the sleeping bag will probably keep you warm enough in an emergency, and the walls will really help cut the wind.

Castle Rock itself is, well, another castle rock. It seems like most places have something either called Castle Rock, or some rock formation that is just so prominent it needs to have a name. I guess when they jut up so dramatically it makes people think of castles, and thus there are probably over a thousand Castle Rocks throughout the world. Antarctica’s Castle Rock is a gorgeous volcanic rock red against the white snow.

Our little party of five climbed part of the way up the rock, but turned back due to the steep, slippery snow. We tried packing the snow into steps, but had no luck. Snow here is kind of weird. Some of it’s so hard you can walk on it without leaving a bootprint. Some of it’s so soft you can’t pack it at all, not even to make a snowball.

Stacy had given us some plastic sheets before we headed out, in addition to all the food, and after getting a closer look at Castle Rock we put the plastic to good use. Francois set the speed record on the next part of trail, and if he had been able to keep that pace up probably would have been able to complete the roughly 12 mile loop we hiked in just a few minutes.

We descended down to sea ice level as we approached Scott Base. On the way we passed Snow Mound City, where we had taken Happy Camper training and Willy Field. Willy Field is located on the permanent ice shelf (300 feet thick) where ski-based planes land. It’s also where my roommate’s team will be launching a few enormous balloons carrying science payloads weighing up to six thousand pounds. These balloons will float up to 120,000 feet, and will be large enough to be visible to us down here. They’re huge, roughly the size of football domes.

We walked past Scott Base and decided to take the Cape Armitage trail back to McMurdo. It seemed a nicer alternative than the road and allowed us to get a little closer to the pressure ridges at Scott Base. We ended up taking a little shortcut and visiting the team’s diving shed at Cape Armitage.

I was beat as we returned to the lab. Hiking in our bunny boots had kept my feet warm and toasty, but since the boots are so heavy, my legs were very tired. Even on a day off, though, Francois and I had a little work to do and so went up to talk with Joe about some of the difficulties we were having with the GPS. He set us straight pretty quickly. I had tried using the latest data saved by the GPS base station, but it had started sampling the satellite data after I had taken the dive and transducer hole information. Francois and I were sure that we had started the base station well before taking any measurements. Oh no, we wouldn’t have any location information for the dives on Friday or Saturday! Fortunately it was just a quirk of the unit – it starts a new data file at midnight Greenwich Mean Time, which happens to be about 1pm local time, right in the middle of our typical dive schedule. By using the older set of data (from yesterday GMT), we were able to compute the locations of the dive site. Whew, disaster averted!

I finished the day by going to the Sunday night Lecture, where the ENDURANCE team presented their project. We had gone to Happy Camper with several of the team members, and since they also have a robot that explores underwater, we were very interested in hearing what they were up to. Their underwater robot is huge compared to ours. While I can pick up SCINI by myself, ENDURANCE would flatten me. They also have some very sophisticated software on board that helps them navigate autonomously, while we require power and control from the surface. Their website is at

http://www.evl.uic.edu/endurance/details.html

If you want to check them out. Very interesting stuff!