Thursday, December 31, 2009

Back at the Lab

Jen and I finally made it back to McMurdo Station! We got stuck at Fryxell camp for a couple of days. The weather over McMurdo was bad, so the helicopters couldn't leave to pick us up. But, the weather in the dry valleys was very nice, so it was a nice place to be stuck. It's good to be back in town, though, because we have to process all of those samples we took to start getting some data! Since we were a day and a half behind, it's been a very busy couple of days (but at least we had a chance to shower and put on clean clothes for the first time in 8 days).

There are a lot of chemical and physical properties we measure on our soil samples. Some of them get done here at McMurdo, and some wait until we get home. One of the basic things we measure here on our soil samples is soil moisture. We want to know how much water is in the soil. Knowing how much water is in the soil tells us how much might be available for organisms living in the soil that need water. (It also helps us standardize all of the other measurements we make. If we express the amount of nutrients per gram of dry soil, it's standardized among all of the different soils we measure, rather than changing based on the amount of water in each sample if we expressed it per gram "fresh" soil.) We measure soil moisture by simply weighing a subsample of the soil, placing it in an oven at 105°C, then weighing it again after 24 hours. The weight lost was water that evaporated from the soil. Jenn and I both have weighed a lot of samples to measure moisture over the past two days.
I also started working on the moss samples I took. To measure the nutrients in the moss, I first have to rinse away all of the soil that's mixed up with the moss. I have to do that using a microscope so that I can see that all of the little pebbles have been rinsed away.

Yesterday, our colleagues from Colorado State arrived from the U.S. So, the lab has become very busy! Tomorrow, the other two group members from Dartmouth are scheduled to arrive, and then our group will be complete! So will 2009!

Monday, December 28, 2009

Getting Our Feet Wet to Sample Moss

Most people think of Antarctica as being a big, barren land with no animals or plants living on it. That is not true! In fact, there are plants growing in Antarctica, even here in the dry valleys. You just have to look very closely to be able to see them, because they are small! The only plants we have in the dry valleys are several species of moss. They grow very slowly and are generally found only in small patches.

Moss has a lot of challenges to face to grow in the dry valleys. It's very dry here, so they 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! Most of the time you do not find moss that is lush and green, because it's usually too cold, too dry, or there's too much sun damage. Sometimes, though, you find moss that was recently uncovered by the water or a rock, and it is green and happy.

But, 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.

We want to learn more about moss's role in the carbon and nutrient cycles in the dry valleys, so one of our projects is to find out where they are getting their nutrients. Mosses grow in the soil like other plants, but are always very close to water. Are their nutrients coming from the soil or the water? Do mosses take up all of the available nutrients, or just some? We're trying to find out by taking from each location a moss sample, soil sample, stream water sample, and groundwater sample. (Groundwater on the edge of a stream can be very different from the stream water, and is more likely the water being used by moss when stream flow is low, which is most of the time!) We will measure the ratio of carbon, nitrogen and phosphorus in the moss tissue and see if it reflects the ratio in the soil or the water. If the ratio (called "stoichiometry") of the moss is more like that of the water than the soil, that would suggest that the nutrient source is the water. We've visited many of the streams and wet areas around Lake Fryxell and taken moss, soil, and water samples. You can see the patch of moss at the base of the rock that my backpack is on. Jenn is in Lost Seal Stream taking a sample of stream water. She pulls the water up into a giant syringe, then snaps a filter onto the end of the syringe and sloooooowly squirts the water through the filter to remove all of the sediment. If you click on the photo to make it bigger, you can see that between my backpack and Jenn is my setup for collecting groundwater. We use a miniature well system called a piezometer. I insert a long tube into the ground using stiff wire, then attach a hand-powered vacuum pump onto the end of it to suck water out from below the stream bed into a flask. The water comes out very, very silty so I will have to filter it using a more powerful setup back at the lab. You can see a groundwater sample on the rock next to my backpack (it's the bottle with the orange label).

We've visited several streams to do sampling like this so far. Each stream that flows into Lake Fryxell has a different ratio of nutrients. If the nutrient content of moss changes the same way that the streams change, this would be a clue that nutrients are coming from the stream and that mosses use all the nutrients that are available. If the nutrient content of the moss doesn't change with the stream and soil, this would be a clue that the mosses only take up a certain amount of nutrients no matter what is available. That would suggest that their role in nutrient cycling is more stable and less likely to change if nutrient availability changes.

This is one of the projects that Jenn and I have been working on this field this past week. We are trying to return to McMurdo Station tonight to process our samples and get ready for the next field project, but the weather is bad and the helicopters can't come get us! Hopefully we will get home tonight or tomorrow morning.

Friday, December 25, 2009

Merry Christmas

Merry Christmas from Lake Hoare, Taylor Valley, Antarctica!

Before we left F6 to come to Lake Hoare, Santa and his elves came to visit us by helicopter. They brought us a giant box of "freshies": fresh vegetables, fruit, and homemade cookies and bread! We aren't normally able to get a lot of freshies down here, especially in the field, so it was a very wonderful treat!
We arrived at Lake Hoare and were set to work decorating. We decorated Christmas cookies, put up the Christmas tree, and made a gingerbread house.
Then, we had a big family dinner! There are scientists from many different projects gathered here, so there were 15 people for dinner. After dinner, we played the "gift game" by the Christmas tree. I got a cool, new water bottle! Now, in Antarctica, it is the day after Christmas, and it is time to get back to work! We'll be hiking over the glacier to Lake Fryxell camp to sample mosses along some of the streams.

Wednesday, December 23, 2009

Changes Brought by Permafrost Melt

We've been in the field for a couple days now taking soil samples. One of the projects we've been working on is to study the effects of permafrost melt water seeps on soil chemistry.

Beneath the soil in the dry valleys there is permafrost. Permafrost is permanently-frozen ground. Beneath the surface, the temperatures are so cold that the water associated with the soil is always frozen, making the soil in the permafrost a frozen block. In the Lake Fryxell basin, where we are, the permafrost starts about 30 cm (about 1 foot) beneath the soil. When the ground gets warm enough, the permafrost can start to melt, and that water moves up through the soil and appears on the surface as a wet patch like this:
As that water moves up through the soil, there are a lot of ions, including nutrients, that get dissolved and move up through the soil with the water. We want to know how much nutrients are moving in the soil profile with that water and how much that changes soil nutrient cycling overall. To study that, we have to dig a lot of soil pits. That's what Jenn is doing in this photo. We dig pits both inside and outside the seep patches to see how their soil nutrients differ.In the pits, we take soil samples from the wall of the pit along the depth of the soil profile. That way we can measure the ion concentrations in each layer.
Last season was a particularly warm year, so there were a LOT o f permafrost seep patches all over the Fryxell basin. We dug many pits and found that nutrients were much more abundant in the seep patches than dry soil, especially at the top near the surface. With more ions and nutrients in them, the seep patches are a very different habitat for soil organisms than what would normally exist in dry soil. That is why we're interested in studying the seep patches. Nutrient cycles could change a lot when permafrost melts, because more nutrients become available and there's more water for organisms to use while they process the nutrients.

This year we're digging more pits and taking similar samples, but we're specifically interested in the sulfur cycle this time. We found that the ion sulfate (SO4) is very abundant in seep patches, but not at the very bottom of the soil pit near the melting permafrost. Other scientists have found that there are a lot of bacteria at the bottom of soil pits near the permafrost that use sulfate instead of oxygen to breathe. These are called "sulfate-reducing bacteria" and they live all over the world. We think that maybe permafrost melting releases a lot of sulfate, but near the bottom layer the sulfate is used up by the sulfate-reducing bacteria. Other scientists have also found that some of the bacteria in the dry valleys use a very old metabolic pathway for sulfate reduction, and we are looking to see if this metabolic pathway is being used by sulfate-reducing bacteria near the permafrost, and how much their activity can change the soil sulfur cycle when permafrost melts. It requires a lot of digging! So far we have sampled 7 soil pits.

Now we have moved camps, and we're now sitting on Lake Hoare. We will be doing some field work here, as well as enjoying the Christmas holiday with our friends from other science groups. It should be a good two days here on Lake Hoare!

Tuesday, December 22, 2009

Finally in the Field

We finally made it out to our first field site in the Dry Valleys. We were supposed to have left yesterday, but the weather was too bad for the helicopters to fly. Today, though, the weather was decent enough to get us out in the morning, and here we are in Taylor Valley!

We do our field work in the dry valleys. These are the valleys in the Trans-Antarctic Mountains that dissect the continent. The presence of the mountains prevent the ice sheet from moving into the valleys, so they are de-glaciated. It is a desert, so there is not enough snow to maintain ice cover on the ground. There is only about 2% of the continent that is not covered in ice, and the dry valleys are a large part of that 2%. Here is a map of the main area of the McMurdo Dry Valleys:
We do most of our work in Taylor Valley. There are three lakes in Taylor Valley, and right now we are on the eastern-most lake, Lake Fryxell, at F-6 Camp. The lakes are covered in an ice cap, but there is liquid water beneath it. That thin strip of white coming in from the left side of the photo is part of Lake Fryxell. These lakes are fed by glacial meltwater streams. That's Commonwealth Glacier in the background, and there are several streams from it that flow into Fryxell. So, there is liquid water in the dry valleys, but only in certain places. If you're not near a lake, stream, or glacier, there's not a lot of water for you to use.

The soil in the dry valleys is very rocky and sandy. Most of the soil comes from rocks that were left by the glaciers that once covered the area a long time ago. So, not all of the soil originates from inside Taylor Valley. Some of it comes from the volcano across McMurdo Sound. Some of it comes from further inland on the continent.

Since we're a day behind, we immediately started doing field work when we were dropped off by the helicopter. So, I'm pretty worn out and it's late at night. I'll blog more about what we're working on tomorrow, after I've had some rest!

Sunday, December 20, 2009

Snow School

Hello everyone! I'm Jenn, one of the new grad students on the team. On Friday, I headed off to snow school for some overnight training in the field. After a brief introduction at McMurdo, we took the bus to a hut on the sea ice and learned how to use some of the gear in our survival kits. Then we walked over to our campsite on the snow and practiced setting up two large Scott tents and six smaller tents. We even built an open kitchen out of ice blocks, complete with countertops and benches! While some people started boiling water on the stoves for dinner and hot drinks, others started digging trenches in the snow to sleep in overnight. While my trench was pretty much a rectangular hole in the ground, some really enthusiastic campers built a snow palace with staircases and underground tunnels leading to multiple rooms. However, my little trench kept out the wind and snow, and I managed to sleep comfortably bundled up in my sleeping bag.

Dinner in the kitchen:

Home away from home:

The next morning, we took down the tents and headed back over to the hut to simulate some emergency conditions we might encounter in the field. For example, we pretended that one of our friends was lost in a blizzard on the way to the outhouse, and we had to find a way to locate him. We put buckets over our heads to imitate a white out situation, and about eight or nine of us grabbed part of a rope attached to the hut and began walking in the direction of the outhouse. Little did we know that we began to double back, and we ended up heading straight into the wall of the hut! Our friend over by the outhouse must have thought it was funny to see a bunch of people with buckets on their heads holding a rope and stumbling in circles. Afterwards, we talked about our mistakes and how we could learn from them. Then, the bus took us back to McMurdo, and we were home in time for dinner.

Friday, December 18, 2009

Getting Set Up

I've been spending the past couple of days getting our laboratory set up and our field gear put together and running. Today I've been assembling the gas analyzers that we use in the field to measure CO2 flux (to measure processes like photosynthesis and respiration). I have to make sure I write down every piece we need to run the analyzers, because if I forget to take something to the field, we can't come back for it very easily! It's not a very exciting job to do, but it's very important to be as organized as possible before we leave for the field on Monday. (Luckily I have some fabulous Florida State gear sent by my cousin Simone to use while I do it!)
The green notebook I'm writing in (with a FSU pen) is lovingly called a "green brain" here. People always have their green brain in their pocket and use it to remember, organize, and plan EVERYTHING. I'd be in trouble if I ever lost my brain! It's how I remember what gear I need to pack for each field experiment, how much each piece of equipment weighs for transport in the helicopter, important phone numbers, GPS coordinates for our research plots, permit numbers for shipping samples... EVERYTHING!

Tomorrow is our last day in town before we head out to Lake Fryxell for our first day of field work. We have more organizing and setting up to do, and a lot of packing!

Thursday, December 17, 2009

Arrival in Antarctica

Jenn and I have arrived at McMurdo Station, Antarctica! On Wednesday, we woke up early in Christchurch, packed our bags and were driven to the airport. There, we boarded a U.S. Air Force C-17 and flew from New Zealand to Antarctica. The crew flying the plane were from McChord Air Force Base in Washington, and they were very nice to us, their "cargo". There were about 40 passengers on the plane- mostly scientists. We also flew with a bunch of cargo destined for the South Pole. The weather was great, so our flight was easy and on time. The view from the window was great once we got over the continent. This is a picture from the porthole above my head on the plane. It's part of the continent that is covered by an ice sheet (which is about 98% of the continent). Off on the horizon you can see the ocean with icebergs floating in it.

The mountain range that crosses Antarctica is (cleverly) called the Trans-Antarctic Mountain Range. Later in the flight, we were even allowed to go up into the cockpit for an even better view!
Then, after a 5-hour flight, we landed at Pegasus Airfield in Antarctica. This is an "ice runway". That means it's built on a sheet of very thick, permanent ice that covers the Ross Sea. So there's not even any solid ground under that ice holding the airplane up!
Here's Jenn in front of the C-17, right after we landed:We've been in McMurdo for one whole day now. We've spent a lot of time in various training sessions. There's a lot we have to learn about how to live in Antarctica, because it's so environmentally protected and the climate can be so dangerous. We've learned about everything from lab safety to light vehicle driving to how to throw out our garbage!

Over the next couple of days, we'll continue setting up the lab and preparing our supplies for the field. There are a few more trainings we have to do, too. Tomorrow morning Jenn leaves for "snow school", which is where she learns outdoor survival skills. Let's hope for good weather for her. Snow school is much more fun when it's sunny!

Monday, December 14, 2009

Time in New Zealand

Today we were outfitted with all of the gear we need to wear while in Antarctica. The board in the top picture shows the variety of clothes they give us: everything from long underwear and socks to coats and hats. We have to try on all of the clothes we're issues to make sure everything fits. I practiced my "ninja look" with the polypropylene base layer we're given. We also have to make sure that all of the layers fit overtop one another comfortably. Underneath that big red parka and the windpants, I am wearing 2 pairs of long underwear, fleece pants, a long undershirt, and a fleece jacket. I was very toasty warm!

Our flight to McMurdo will be tomorrow at 9 AM (New Zealand time). That means we have some extra time to spend around Christchurch. My favorite place to go in is the Botanical Garden. It's summer here, so all of the flowers are in bloom. It smells wonderful, and it's so nice to enjoy the sunshine and greenery before heading to Antarctica.
Jenn and I also went to the Canterbury Museum, where we learned a lot about the history of New Zealand and its people. New Zealand was originally colonized about 800-900 years ago by Polynesians. So, the ancestors of native New Zealanders are related to the people of Hawaii and other Polynesian islands in the South Pacific. These early people lived in New Zealand (or Aotearoa, as they called it) by hunting a bird called a moa. These are large, flightless birds that only ever lived in New Zealand, but are now extinct because they were overhunted by the early people! These early moa-hunting people of New Zealand are called the Maori. They have a very unique culture with their own language, art, and traditions. They hunted the moa until they were driven to extinction, at which point they relied more on farming and fishing. They were great craftsman that made beautiful wood carvings and ornaments made from jade and Paua shells. Their lives of course changed a great deal when New Zealand was colonized by Europeans, mainly the British, about 250 years ago. This is very similar to the U.S., where the Native Americans practiced their own culture until it was interrupted by European colonists. But, many aspects of Maori culture still remain in New Zealand. Maori is still one of the official languages of New Zealand, and even New Zealanders of European descent know many phrases in Maori, and you find Maori translations of most information given on signs and notices. Some of their cultural legacies in New Zealand include the haka dance (a war dance with a lot of shouting), and their art is still very much a part of New Zealand culture.

Well, if all goes according to plan, we will leave for McMurdo tomorrow morning and my next blog post will be from Antarctica! All but one piece of our luggage has arrived. Hopefully the final piece will come today so that we land in McMurdo fully-prepared for the next two months!

[Photo credit: Maori wood-carving from Wikimedia]

Sunday, December 13, 2009

Arrival in New Zealand

Well, Jenn and I have made it safely to Christchurch, New Zealand. It has been a long two days and every leg of the trip ran a little bit late. Our bus was a little bit late getting to the Boston airport. We left Boston a little late, so arrived in Los Angeles a little bit late. Luckily there was still enough time to meet our connection to Sydney without any trouble (but no time to stop and eat dinner). Our flight left Los Angeles only about 20 minutes late, but landed in Sydney about 40 minutes late. That caused us to miss our connecting flight to Christchurch, NZ. They arranged for us to get a new flight to Christchurch, NZ on a different airline, but it was still a close connection due to our late arrival. When we arrived in Sydney, we had to be rushed off the plane and driven on one of those big golfcarts by airline employees to our gate. Luckily, we made the new flight on time! Unfortunately, our luggage didn't. So, when we arrived in Christchurch a couple hours later than planned, our luggage wasn't there! And to make it worse, the U.S. Antarctic Program's headquarters were closed by the time we got in! So, all we could do was head empty-handed to our hotel and wait until tomorrow morning.

Now, I am sitting in the lounge of our favorite B&B in Christchurch with a cup of tea and biscuits. Luckily I put a lot of necessities in my carry-on bags, so I have showered and changed my clothes after 48 hours of travel and I feel much better! Hopefully our luggage will arrive on the next flight from Sydney and we'll be able to pick it up tomorrow. Then, we can start enjoying our two days in New Zealand!

Now, it is time for dinner. Keep your fingers crossed that our luggage finds us before we leave for Antarctica on Wednesday!

Friday, December 11, 2009

And We're Off!

We've begun our journey south! Jenn and I are on the bus to Boston now. The first leg of the trip has begun.

Thursday, December 10, 2009

Almost Time to Leave

We're all packed up to go! Tomorrow morning Jennifer and I start our 5-day journey to Antarctica. First, we fly commercially to Christchurch, New Zealand. We're getting routed from Boston, through Los Angeles and Sydney, Australia to get to New Zealand. It'll take a total of 33 hours from the time we leave Dartmouth until we arrive in Christchurch, but because of the International Date Line, we'll land there 2 days later.

Check out this interactive map if you want to find out more about our travel plans.

We'll be in Christchurch, NZ for 3 days before we finish our trip and fly to McMurdo Station in Antarctica. While in Christchurch, we'll get fitted for all of our Extreme Cold Weather Gear, receive some safety training, and of course enjoy some of that great New Zealand summer weather!

Let's hope the weather is good for our travels and that we don't encounter any major delays! I'll keep you posted.

Friday, December 4, 2009

One More Week!

We are at the one-week mark! We leave for Antarctica on December 11, exactly one week from today. I'm finishing all of the labwork that needs to be done before I leave and getting the last of our gear packed up. It is a busy time for our group here at Dartmouth!

I'll keep you posted on our travels as we make our way across the globe.

Monday, November 16, 2009

Welcome to Season 3!

Welcome to another field season of research in Antarctica with the Dartmouth polar soils research group!

We are making preparations to leave the U.S. and head to McMurdo Station on December 12. It is a busy time of preparations for us at Dartmouth! We have a lot of work to finish up, travel plans to arrange, and supplies and equipment to gather. In just a few weeks, we'll be on our way.

If you are new to the Polar Soils blog, here is some information that might be useful to you:

Where we go:
When most people think of Antarctica, they think of ice. When you're on the continent of Antarctica, it's referred to as being on the "ice." However, the area we study is a polar desert called the McMurdo Dry Valleys, where the glaciers have retreated. Just like deserts in the U.S., there's very little precipitation, so there's actually bare soil, not just ice and snow! The red dot on the map shows where McMurdo is located:

What we do:
Our research is in the field of soil biogeochemistry, which is just a big word that means we study the way nutrient elements move in the soil. We are especially interested in carbon, nitrogen, and phosphorus, since these three elements are so important for all forms of life. We study how the living organisms influence nutrients in the soil. All of the animals in the dry valleys are microscopic (except for the scientists, of course). While other areas of Antarctica have penguins and seals, the dry valleys' largest animal is a nematode. A predatory nematode is the top of our foodchain- the equivalent to a lion in the Serengeti! We also study the mosses growing in the dry valley soil. Mosses are the only plants growing in the dry valleys and the only living things you'll find above the soil- the equivalent to the redwood forests in America!

Who we are:
Our research team is a little bit different from last year. There are four soil scientists going to Antarctica from Dartmouth. The leader is Dr. Ross Virginia, a professor at Dartmouth who has been going to Antarctica for many years. Also on the team are me (Becky, a postdoc), Julia and Jen (both graduate students). While on the ice, we will continue to work very closely with another group of scientists from Colorado State University led by Dr. Diana Wall that specializes in the nematodes (they have a special nematode blog). Together all of us study the nutrients and biology of the McMurdo Dry Valley soils.

About the blog:
Our blog is designed to be an educational tool for elementary and middle school classrooms, but all readers are welcome to follow along! Teachers interested in using the blog in their classes are welcome to contact me (contact information available through my website, listed under my Profile on the bottom-right).
On the right-hand side, there are some links with additional information that is useful for both kids and adults. Many links are added throughout the season, so keep an eye on them!

Saturday, March 14, 2009

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!

Sunday, February 1, 2009

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!

Saturday, January 31, 2009

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!

Friday, January 30, 2009

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...


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!

Sunday, January 25, 2009

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!

Thursday, January 22, 2009

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.

Tuesday, January 20, 2009

2nd Annual Camp Hair Contest

It is time for the Second Annual McMurdo Field Camp Hair Contest!

The water restrictions in the dry valleys means that we are not able to shower or wash our hair while we're out at field camps. That means that people's hair gets very dirty and oily, which of course leads to some very fabulous hair-do's! This is what we call having "camp hair." Having great camp hair is a matter of pride, and the person with the best camp hair is honored throughout McMurdo. So, once again, I'm going to leave it up to everyone reading my blog to decide who has the best camp hair for the 2008-09 field season. Review the photos below of our "camp hair" contestants, and send in your vote! Anyone reading this is welcome to vote, and can do so by sending an email with your choice to me.

Let's meet this year's contestants!

Elizabeth:Returning champion Elizabeth is once again demonstrating her all-natural, gravity-defying camp hairdo. While the front of her hair has been flattened by hours of lying under a hat, don't let that fool you! The back of her head is 4 inches taller than the rest of her! Photo taken after 5 days in the field.

Katie:Recent Dartmouth graduate Katie is featuring the Cindy Loo Who look. The dry air can't keep her hair down, oh no. This springy look comes after 5 days in the field under the influence of wind, sunblock, and home-made wool hats.

With only 3 camp-showers over the course of his 40-day field stint, stream-team member Corey's hair has been dirtied, wind-blown and pelted by sand particles. Much like this ventifact. Coupling his hairdo with a savage beard, Corey presents a look that is hard for our other gals to match.

Breana:This wormherder postdoc's look just screams "Troll Doll". Breana does not need multiple days without a shower to master this fine look. On Day 1 in the field, this is her hair's reaction to a mere few hours of being trapped under a hat. When her hair is released from under her hat, watch out!

There they are: the 2008-09 season's Best Camp Hair contestants. May the voting begin! The champion Camp Hair will be declared a week from today.
After a full day of weather delays on Saturday (and our wonderful luau), we finally made it back out to F6 on Lake Fryxell. However, the bad weather took out our internet! We finally had IT guys come in today to fix it, so we've been reconnected with the outside world.

We've been busy with lots of field work for the past several days. But, it's been very cold! I'll catch you up on all of our work since we lost connection over the next few days. Right now, it's time for a hot drink and some dinner!

Friday, January 16, 2009

More Weather Delays

The weather has been very uncooperative for the past week and a half! It was hard getting everyone back into town after our field work last week, because the weather was bad and the helo's couldn't fly. Katie, Elizabeth, and Ross got stuck out at Lake Fryxell camp for an extra day because no helo could get into the Valley to pick them up. I kept trying to leave McMurdo to go to Lake Bonney, but that trip kept getting canceled. We finally made it to our destinations, after a couple days of delay. We all made it back to McMurdo on Tuesday, after completing most of the work we needed to do last week. Since then, we've all been back in McMurdo processing samples in the lab. Today, we are once again trying to get back to the field. We were all supposed to fly out this morning to F6 camp on Lake Fryxell. But, it's snowing again, and you can only see about 200 m across McMurdo Sound, so we're not going anywhere!

Since we're all stuck here in town, we decided to have a luau on the Florida Keys (after my walk to the post office to pick up some super fun packages that were sent to me). We decorated ourselves using my Luau in an Envelope kit. And we basked on the edge of the miniature beach that was sent to me from Florida (which I'm holding in my hands). Here we are partying in the hallway in the science building: Karen, Katie, Diana, Breana, Uffe, me, and Bishwo. Of course, we also decorate any passers-by, so now there's a lot of people in the science building in Antarctica that are dressed for a luau!There's still a small chance we could get out to F6 later today. But the weather is not looking so good, which means we may be stuck in town until Monday. I'll keep you posted!

Thursday, January 15, 2009

Nitrogen Fixation

Nitrogen is the most common element in the atmosphere and the air we breathe (78%), and it is a necessary element for life. It is an important element in proteins and enzymes, including the enzyme that allows plants to photosynthesize. However, the form of nitrogen that is in the air is not usable by plants. Plants use nitrogen compounds in the soil, not the nitrogen gas that is so abundant in the air. So how does all of that nitrogen from the air get into the soil for plants to use?

There are some organisms called cyanobacteria that can use the nitrogen gas in the air. They have special cells (called heterocysts) that can can grab nitrogen gas from the air and change it into a usable compound. This is a process called "nitrogen fixation". The cyanobacteria use that new form of nitrogen to grow. Then, when the cyanobacteria dies and decays, that usable form of nitrogen is released in the soil for plants and animals to use.

We see a lot of cyanobacteria near the streams and lakes in the dry valleys. It will grow in thick mats, like you see here. All of that black stuff is a bunch of cyanobacteria matted together, making a layer on top of the soil. One of the things we want to know is how much nitrogen the cyanobacteria are fixing. That way we can estimate how much nitrogen they are adding to the soil for the mosses and other soil animals to use. Unfortunately, it is not very easy to measure nitrogen fixation. But, we can measure a similar chemical process called "acetylene reduction" that helps us calculate how much nitrogen is being taken from the air. To measure acetylene reduction, we place small amounts of cyanobacteria (and mosses with cyanobacteria growing on it) into air-tight chambers, like the clear plastic ones in this picture. We then add a gas called acetylene to the chamber. The cyanobacteria will change the acetylene to ethylene in a process similar to how they change nitrogen gas. We leave the pieces of cyanobacteria and moss in the chambers for 1-5 hours. Then, we take a sample of the air inside the chamber and put it in a special vial. We then measure the amount of acetylene that has been changed to ethylene, and we can then calculate how much nitrogen would have been fixed from the air.

Here's Elizabeth and Ross measuring acetylene reduction at one of our field sites. Elizabeth is using a big syringe to pull new acetylene from a bag to inject into the plastic chambers. Ross is using another syringe to remove a gas sample from a chamber that contains some cyanobacteria.
We will take the vials of gas samples back to Dartmouth and measure the concentration of ethylene on one of the machines in our lab at home. So, we're doing the work now, but won't see the results for another month!

Sunday, January 11, 2009

Dry Valley Wildlife

Most people think of Antarctica as being a big, cold, dead place. When you see photos of our research in the dry valleys, you don't see animals. But, there are animals there, in every single one of those pictures! You just can't see them, because they're microscopic. Here's some information about the main types of micro-organisms that live in Antarctic soils.

Also called roundworms, nematodes live EVERYWHERE in the world. You can find them in every biome in the world. They live in water, soil, ice, even in other animals! They are the most abundant animal in the world. In the dry valleys, we find more nematodes than any other animal. They are what our collaborators at Colorado State focus on studying. We have three main species that live here. The most numerous species, Scottnema lindsayae, is in the photo to the left.

Nematodes eat a lot of different things. Some, like the guy at the left, eat bacteria. Others eat fungi or algae, and some are even predators that eat other microscopic soil organisms. In the dry valleys, a predatory nematode is the top of the food chain! Though nematodes are small, they have a lot of very well-defined characteristics. Here is a very close-up picture of the mouth-parts of a bacterial-feeding nematode. They use those long branches on their mouths to scrape bacteria off of soil surfaces.

Rotifers also live in a lot of different environments, including fresh water, saltwater, soils, and other watery environments. A rotifer eats by waving the hairs around its mouth (at the top, in this picture) to catch things floating in the water. The moving action around their mouth looks kind of like a wheel, which is how they got the name ROTifer (like rotate). The "foot" (at the bottom of the picture) is to anchor the rotifer when it doesn't want to move.

Tardigrades are also called water bears, and looking at the picture I think you can see why! They even have claws at the end of their feet, which you can see in this very close-up microscrope picture that Uffe took of a tardigrade foot. The claws let them hold on to something as they float through water or the water-filled spaces in the soil. Tardigrades eat with a stylet that they use to pierce animal and plant cell walls.

Tardigrades are able to live in a lot of extreme environments, and are found everwhere from the Himalayas to the ocean floor to Antarctica. They can withstand the pressure of a vaccuum, radiation, dehydration, and both incredibly high and low temperatures. There are even experiments that test tardigrades' ability to live in open space! In the dry valleys, they especially like to live in the moss and algae patches, where food and water are readily available.

The soil environment in the dry valleys is a very hard place to be an animal. There's not a lot of water, not a lot to eat, and it is very cold! Most of these micro-organisms have a special ability to help survive in such a harsh environment. They can go into anhydrobiosis, which essentially means they can freeze-dry themselves. They can push out all of their water and curl up, so that they don't freeze and die. Their metabolism drops to almost a stand-still! They can stay in anhydrobiosis for a very long time, and immediately wake up if water becomes available.

Part of our research looks at what animals are living in the soil. We want to know why they live in some places in the dry valleys, but not others. We want to know how nutrient cycles in the soil change when animals are there or not. So, we spend a lot of time on the microscopes looking at the animals we can extract from the soil. One of our team members, Byron, made this awesome video through the 'scope featuring three of our soil superstars: nematodes, rotifers, and tardigrades.


[Photos of each are from the linked websites: S. lindsayae, rotifer, tardigrade. Video by Byron Adams. Tardigrade foot photo taken by Uffe Nielsen.]