Saturday, January 19, 2008

Day Tripping

This week we've been taking a lot of day trips into the field. Rather than spending several days or a week out in the field, we fly out in the morning, spend all day collecting samples, and return to McMurdo in the evening.

Elizabeth and I have gone back to both Lake Fryxell and Lake Bonney on day trips to measure soil respiration. Two weeks ago, water and nutrients were added plots of soil by both lakes. Elizabeth and I went to the plots to learn how much the soil animals were breathing after the additions. We want to know which nutrients make the soil animals breath the most. We took our measurements, and now we have to look at all of the data to answer the question!

We've mostly been working in Taylor Valley. But, there are other valleys in the area that are part of the Dry Valleys. Each valley in the area was formed by different glaciers at different times in history, so the soils in each valley are different. We want to learn more about the other valleys, not just Taylor Valley! So, we took a trip to Wright Valley, which is slightly farther north. It was fun to fly there, because I got to see new parts of the Dry Valleys from the helicopter!We visited two places in Wright Valley. First went to the Dais, which is a flat, elevated area with very interesting soils. The carbon in the soil (which soil animals eat to get their energy) is very different from other soils we've looked at. This is why we wanted to go back and look some more! We took soil samples from many different places around the Dais, and we've brought it back to the lab. We will analyze the soil to learn more about the carbon and other nutrients from all over the Dais. Here is a picture of the four of us after our sampling at the Dais:


Here is a video I took from the helicopter leaving the Dais. You can see how flat the top of the Dais is, and how it drops off very steeply to the valley below.
video

Next, we went to the other end of Wright Valley to Lake Brownsworth. We were looking for mosses. While there are many places in Taylor Valley to find mosses, there aren't many in Wright Valley. We looked extra-hard along Lake Brownsworth, but didn't find any! We wonder what makes Wright Valley so different from Taylor Valley that keeps mosses from growing there. So we took some soil samples, and hopefully we will find out!

We want to look at other Dry Valleys, besides Wright and Taylor Valleys. Tomorrow Elizabeth and I are going to Garwood Valley and Marshall Valley, which are farther south. We will sample soil and try to find mosses there, too.