Continuing the work back at Dartmouth

We've been back at Dartmouth for about a month, now. Our soil and moss samples have been shipped from Antarctica so that we can continue to analyze them. We store the samples at Dartmouth in big freezers at -20°C (cold enough to keep their chemical properties from changing, so that they remain the same as when we scooped them up from the Dry Valleys).

We spend a lot of time in the lab performing our analyses. Here, I am weighing some soils into a tin to measure their moisture content. We will also measure the amount of nutrients, ions, microbial biomass, and many other chemical properties of the soils. We will then have to process the data and see what we learned from the field season. There will be graphs to make, papers to write, and new experiments to design from what we learn. It will take a lot of time, and will keep us quite busy until next December when it's time to head back down again!

I've also been to visit my friends at Thetford Elementary School, who followed my blog while I was in Antarctica. I was able to join their class for a morning to talk about Antarctic science, show photos and rock samples, and eat delicious home-made snacks. It was a great home-coming!

We're Done!

Well, the field season is officially over! We have closed up the lab. We have shipped all of our samples. We've packed up our belongings. There's no more work to be done! Tomorrow we will fly back to Christchurch, New Zealand.

Tonight, we have to pack up our luggage and turn it over to the crew that will load the C-17. This is lovingly called "bag drag", because it involves dragging our orange bags up the hill to the transport building. There, everything is weighed (including us!), and our luggage is put on pallets to load onto the aircraft when it arrives. Tomorrow we will go back to the building with our carry-on luggage to be transported to the ice runway where we'll meet the C-17. It's a day full of waiting!

The last piece of business I had here at McMurdo was to show my new Wubble friend around town. The Wubble is visiting from Thetford Elementary School in Vermont. He learned a lot about Antarctica while he was here. I also learned a few things about Wubbles. I learned that Wubbles do not like wind! He had a hard time standing up for the photo... :)

Ok, it's time for bag drag! Keep your fingers crossed that weather and mechanics cooperate, and I make it back to Christchurch in good time!

How to Walk in the Dry Valleys

The dry valleys are a very sensitive ecosystem. Because it's such a harsh place for organisms to live, they do not grow very fast. We don't want to make it any harder for them! Plus, we want the ecosystem to stay as clean and healthy as possible, without creating too much of a disturbance ourselves. We want to avoid damaging the ecosystem and the organisms as much as possible. Therefore have to be very careful when we work in the dry valleys.

The main way we can disturb the environment is by walking. We have to walk a lot to get to our camp and field sites for work. There are very specific ways we walk here to minimize the amount of disturbance we create with our feet.

When we're walking on the ground to and from our field sites, we always walk single-file so that only one line of footprints is made. We follow paths made by the polygon cracks in the ground. These cracks are made by the repeated freezing and thawing of the ground, and they form a variety of interesting shapes, called polygons. When you look at the ground from a helicopter, you see all of the polygons that make up the dry valley landscape.

Our previous research has shown us that soil biodiversity is lowest in these cracks. There are fewer animals living in the soil at the cracks than in the flat part of the ground. So, we try to always walk in the cracks. That way, our footsteps are trampling the least amount of organisms as possible. It unfortunately means that we can't walk in a straight line anywhere! You have to follow the zig-zagging of the polygon cracks to get from one place to another, which means sometimes you walk twice as much as the distance you need to go! Here's what it looks like as you walk in the polygon cracks:

When we're working at our field sites, we try our best to not trample the soil too much. We stand on rocks as much as possible. If we want to sit down, we sit on rocks, like Katie is doing:

Sometimes we work near streams, especially for our moss research. We don't want to disturb the algae and moss growing in the sediment in the streams. To avoid trampling anything, we rock hop. Every step we take has to be on a rock, where algae are not growing. This is pretty easy when the stream flow is low and the rocks are exposed, but it can get tricky if the water is high!

Sometimes we even have to rock hop to walk across the dry ground. The polygon cracks cover most of the soil, but they're not everywhere. When there are no cracks, we rockhop across the ground so that we don't disturb the soil!

Most of the places we walk are on soil and near streams. But, sometimes we walk on the ice. We don't have to be as careful about the ecosystem when we're on the ice, because there's not much damage we can do. But, we still have to be careful! The ice is slippery, of course, so we wear stabilizers attached to our shoes that give us better traction. Also, the glaciers and lake ice are covered with cryoconite holes. These holes are formed when dirt or rocks are blown onto the ice. Because the rocks are dark, they absorb more of the sun's heat and melt the ice around them. The rocks sink down as the ice melts, leaving a lot of little holes in the ice. These holes might be several inches deep, or even deeper! They can be just a couple inches wide, or they can be much bigger! It depends on the size of the rock that landed there to melt the ice. Sometimes the holes are filled with water. We have to be careful not to step in them, because if you do, you'll suddenly find yourself standing in a deep, wet hole! Sometimes the cryoconite holes have been covered back over with a layer of ice on top that maes the holes hard to see. But, that layer of ice is not strong enough to hold a person, so you crash through unexpectedly. You have to keep an eye on the ground so that you know you're stepping on thick ice. This is what it looks like to walk over the top of a glacier in the dry valleys. This is from our Christmas Eve hike over the Canada Glacier:

We do a lot of walking while we're here. Now you know what it's like!

Camp Hair Contest Winner

The week has passed, and the votes have been tallied. The winner of the 2008-09 Best Camp Hair Contest is...

BREANA!!

This proud wormherder celebrates her victory by sporting her favorite facial hair accessory- a mustache! It's a very expensive mustache to have grown.Congratulations Breana!

Old Antarctic Explorers

Antarctica has a long history of exploration. Explorers, mainly from Europe, were frequently coming to Antarctica during the late 1800's and early 1900's during what is called the "Heroic Age of Exploration". The goals of the explorations were mainly scientific. They wanted to study the geography of Antarctica and reach the South Pole. This was a very difficult time to be an Old Antarctic Explorer. Resources were scarce down here, working conditions were strenuous, and of course the weather was harsh! Explorations tended to be a feat of endurance, both physically and mentally. A lot of people died during expeditions to explore Antarctica and reach the South Pole.

One particular OAE that is important in the McMurdo area is Robert F. Scott. He led several missions to this area of Antarctica. After exploring a lot of this region, Scott led a party in an attempt to reach the South Pole. He was racing the Norwegian explorer, Amundsen, to be the first to reach the South Pole. Unfortunately, the trip did not go well for Scott. They did reach the South Pole, but they were beaten there by Amundsen's party. And, on the journey back to the coast (here at McMurdo), everyone in Scott's party died due to the harsh conditions. Surprisingly, they were only 11 miles away from a supply hut when they died. It is a very unfortunate story!
A statue of Scott is in Christchurch, NZ. We always visit it on our way down to the ice. Here's Katie with the statue, back in December when we were passing through.

A lot still remains of the early explorations. Near McMurdo, there is a hut that was built in 1902 by Scott during his first mission, called the Discovery Mission. The hut is called (cleverly) Discovery Hut, and sits on Hut Point just outside of McMurdo. Several huts like this were built around Antarctica to be supply stations for explorers along various points on their journey. It is Discovery Hut that Scott's South Pole party was trying to reach when they died.Because Antarctica is so cold and dry, these huts are very well preserved. The food and equipment that explorers used are still in the huts. We were lucky enough this year to be able to go inside Discovery Hut and see what's in there! Here's a video I took walking through the hut. You can hear Breana telling some facts about the hut and Katie asking questions. It's neat to see all of the old supplies, like what kind of food they eat and clothes they wore!

Some of the facts Breana is reading:
These huts were built in Australia, fashioned after Aboriginal huts that were designed to keep cool during the hot summers. Scott thought that it would work the same for keeping warm in cold Antarctica. But, he was wrong! The building was not warm enough for people to live in, so it was used for storage and cooking. Instead, the people lived on the boat just offshore. They heated the building with a blubber stove. That's the brick structure in the floor towards the end of the video. You can sort of see the huge chunk of freeze-dried whale blubber behind Uffe at the beginning of the tour (it's in a shadow, so hard to notice).

It was pretty neat to be able to see this little piece of Antarctic history. It's amazing to think about the conditions that the early explorers had to deal with. They're the same type of conditions we deal with here, but we're much better equipped now!

Winding Down

Our field season at McMurdo is starting to wind down. Ross is leaving today to head back to the U.S. Katie, Elizabeth and I are here just one more week to finish up our work. We are scheduled to head back to New Zealand on February 2.

We have just two more days of field work left for this coming week. Other than that, we are processing the last of our samples and breaking down the lab. We are cleaning out the lab, returning field gear, and gathering up our shipments to send home. All of the soil and moss samples we've collected over the season are getting boxed up to ship back to Dartmouth. We will have a lot more work to do with them once we return home.

It will be a busy week!

The Dry Valley Forest

As I've said before, Antarctica is a very hard place to live. It's not just hard for animals, but also for plants. It's very dry, so plants cannot get much water to grow. The only time water is plentiful is during the 14 weeks of the year when the meltwater streams are flowing, and that water is only available if you're right next to the stream. Sunlight is also a problem. During the winter there's no sunlight for photosynthesis, but during the summer the sun can be so intense that it can actually damage plants. So, it takes a very hardy plant to be able to grow here!

The only plants we have in the dry valleys are mosses. Very short mosses. There are no vascular plants, which are what most people think of when they hear the word "plant". Mosses mainly grow in patches along streams or beneath snow patches, which is only a small percent of the land area. They grow incredibly slowly. We're talking less than a millimeter of growth per year! Most of the moss we see look like the photo above from right outside the Lake Fryxell camp hut. They're not lush and green, because they're usually too cold, too dry, or have too much sun damage. But, sometimes you find a nice, lush green patch like the one below! This patch was probably recently uncovered from water, so is still very happy.

One of the really cool things about this patch of moss that Elizabeth, Katie, and Ross found is that it has reproductive structures. Moss is able to reproduce in two ways. It can reproduce by itself, where bits of the moss break off and become a new moss plant. In the dry valleys, these small bits of moss might blow in the wind to a new location, so that moss spread to new areas. Moss can also reproduce with each other. For this, the moss grow special structures. These special structures act like male and female parts, so that the sperm from the male structures fertilizes the female structures, forming spores (which are sort of like seeds in plants). When they're ready, the spores are released from the female structures to seed new areas. (Click here to see a video of moss reproduction.)

It is generally thought that moss in the dry valleys spread by pieces breaking off and becoming new mosses, not by developing spores. Growing the special reproductive structures requires a lot of energy and resources that are very hard to come by in the dry valleys. But, in this happy patch of moss, we see reproductive structures! Those white-ish stems coming up are the structures that contain the spores. Here's what one looks like under the microscope:


Moss is the only above-ground life in the dry valleys. All of the other organisms live in the soil, not on it. So, moss are in a way like the redwood forests of the Antarctic Dry Valleys! They are one of the few sources of food for soil organisms. When mosses die, they decompose in the soil, just like plants in warmer climates. The carbon and nutrients released from mosses when they decompose are probably a very important part of the soil food web. That is why so much of our research this year focuses on mosses. We want to know more about their role in the carbon and nutrient cycles in the dry valleys. We measure their photosynthesis rates, so that we know how much carbon they are taking from the air and putting into the soil. We measure their nutrients, so we know what type of food they are providing to the soil organisms. We measure how they respond to changes in moisture and nutrients in the soil, so that we know how stable their role is in nutrient cycles.To see how the nutrients in moss respond to changing the nutrients around them, we spray salt solutions that contain nitrogen or phosphorus onto the mosses (very similar to the stoichiometry experiment using the "hula" cones). Here's a patch of mosses next to one of the streams. It's buried in silt a bit, but there are mosses down there! Katie is spraying the nutrient solutions on them. While we were at F6 this week, we took samples from the plot to see if adding nutrients around the mosses changed the nutrient content of the mosses themselves. We also have these plots set up around a few other streams that we will have to sample in the next week.