Geology is like a big puzzle. The area where we worked, Duthier's Point, was once covered by a glacier. Now it isn't. But when did that happen? How can we find out?
Greg was looking for rocks that would give us clues. Since I was his assistant, I was there to help him look for rocks but mainly for safety. Greg's work involves a lot of climbing up and down rocks, and it would be too risky to send one person off alone, especially in Antarctica.
In search of clues, we took a helicopter to Duthiers Point. I loved riding in the helicopter and seeing the glaciers and icebergs from above. The ship looked so small! Once we were on land, we started looking.
We were looking for rocks that didn't belong, called glacial erratics. When glaciers expand, they pick up rocks along the way and drop them in new places. It's pretty easy to spot them. In this case, they were quartz, which is much shinier and lighter than the rocks that we were standing on. The problem is that Greg needs glacial erratics that haven't been covered by snow. If the glacier retreated but then snow covered the rock, Greg's techniques for determining how long the rock had been exposed wouldn't help. The rock can't tell the difference between being covered by a glacier and covered by snow! So we needed to find a glacial erratic that was perched high up, not in a hole or or protected by other rocks.
We didn't find any good rocks at our first site, so we started climbing. We climbed. And climbed. We made it down 300 feet of rock until we were almost at the sea. As we climbed, I though about two things.
The first was the penguins. They were everywhere, perched only a few feet away from me. They had their babies on their feet and they were ridiculously cute. We're not supposed to approach them, but they didn't seem to care about us at all.
The second was memories of the last time I had done any climbing at all, which was about 8 years ago and was not nearly as challenging. Greg is an experienced climber; I am not. I was terrified, hanging on to the edges of slippery, crumbling rocks for dear life. But I kept going, because I hate to admit that I can't do things and because every time I turned around, I saw views that were more beautiful than ever.
When we made it to the bottom, we were in the middle of a penguin colony that now surrounds a GPS station. Greg had to check on the station, which transmits data to scientists back home. The penguins have now moved in all around it and continued to ignore us.
After spending some time with the penguins, we headed back up the cliff. The plan was to pick up any good rocks that we had spotted on the way down - but we hadn't found any! Climbing up is always much easier than climbing down. I think that's because you're not looking in the direction that you might soon be falling.
At the top of the cliff, I rested for a bit while Greg called the ship and asked them to send the helicopter to pick us up. While we were waiting, we wandered around a little more and there it was: the perfect glacial erratic, perched in an unprotected location. Greg tried to break it so that we could bring home a smaller, lighter piece, but it was too hard and he decided to keep the whole thing.
The helicopter came and took us back to the ship. I had another ride with a great view. When I got back, I quickly showered, ate dinner, and collapsed into my bunk.
Posts
No comments:
Post a Comment