Coastal upwelling

You wouldn't think that the oceans around Antarctica would have a lot of exciting marine animals. But it does! The shores around Antarctica have quite a variety of marine life, because it is a zone of coastal upwelling.

The water in the ocean doesn't stay in one place. Water moves. You're probably familiar with currents and tides, which are a couple ways that water moves around in the ocean. But water also moves up and down in the ocean, not just around the surface. Here's how.

Water that is on the ocean surface gets pushed around by the wind. When the surface water is pushed away from an area, other water has to move in to replace it. Along the coast of a piece of land, there's no surface water to replace it, so the bottom waters have to rise up to replace that water. Where the bottom waters come up to the surface is called "upwelling".

The surface waters being pushed away will move around the surface and eventually sink to the bottom. It will then eventually upwell to become part of the surface ocean again. It's a big conveyor belt that moves water up and down, in addition to around the surface.

While water is on the bottom of the ocean, it collects a lot of nutrients. The nutrients come from dead things that sink to the bottom and start to decompose. So, at areas where bottom water is rising to the surface, it is bringing along with it a lot of nutrients that had been collecting. Those nutrients are important for living organisms at the surface.

Around the coast of Antarctica, the westerly winds push water away, and it is replaced by the cold, nutrient-rich water below. The high level of nutrients in the upwelled water around McMurdo mean that there is a lot of productivity. There's a lot of phytoplankton in the water that use those nutrients to photosynthesize. Because there's a lot of phytoplankton, there are a lot of animals that eat the phytoplankton, and therefore a lot of animals that eat those animals... a whole food chain! So, there's a lot of animals living off the coast of McMurdo. Some of them are very colorful, just like in the tropics!

The marine biologists here at McMurdo keep a touch tank with some of the animals they catch. Here's what I saw in the touch tank:There's a lot of different types of animals in there, of different shapes and colors. And they all live right here near McMurdo! It's all of this life that lets the oceans support the larger ocean animals that you might be more familiar with:(See the whale and the penguins at the ice edge?)


Even though it's so cold and icy, the oceans are home to several species of whales, penguins, and seals. They can live here because of the upwelling that brings all of those rich nutrients to support the entire food chain in ocean around Antarctica.

[Photo credit: upwelling diagram from sonoma.edu]

Merry Christmas!

I hope everyone had a great Christmas. For the holiday, I hiked from F6 with the Stream Team to Lake Hoare, where everyone in Taylor Valley gathered for Christmas.

To make the journey, we had to ride the ATV across the ice covering Lake Fryxell to the other side of the lake. Then, we hiked up the hillside, crossed the Canada Glacier and hiked down the other side to the camp at Lake Hoare. It's the Antarctica version of going over the river and through the woods to Grandmother's house.

Here I am with the crew from F6 as we hiked over Canada Glacier:

At Lake Hoare, there are a lot of great Christmas traditions. One of the most fun is building the gingerbread house and decorating Christmas cookies! Here's this year's creation. We use only edible items to build the house, including the Twizzlers that my sister sent me in a care package. This year's gingerbread house is even energy-efficient, with solar power and a wind generator!
After the decorating, we have a big family-style dinner of ham, asparagus, potatoes, and bread pudding. We follow that up with coffee while playing the gift-swap game. Then, we turn the lights out and have a dance party until we get too tired and crawl into our tents to sleep.

It was great to spend time with my Antarctic family in the dry valleys! It was a fun Christmas as always. Here's the beautiful view we had from the front door of the hut around midnight on Christmas:

Have a happy, safe holiday season!

Patterns in Antarctic Soil

One of the most noticeable features of the soil in the dry valleys are the strange shapes that cover the ground. These are most noticeable when you're flying over the dry valleys in a helicopter. The irregular shapes are created by cracks that develop in the soil.

These polygons in the soil are very large. They can be many meters across. To give you a sense of scale, here's an aerial shot from a helicopter of F6 camp where I'm staying right now. You can see the polygons in comparison to the hut.


And here's what they look like from the ground. There's still soil the cracks. The cracks are not gaping holes that you can fall into. They are just crevices filled with finer-grained sand than the rest of the soil.
The cracks are created by the freezing and thawing of the ground ice below the soil. Water in the soil expands when it freezes and shrinks when it thaws, which creates the crack, and the finer-grained soil falls into the crack. Because ice and freezing plays a role in the formation of the cracks, they are called "cryogenic cracks".

Our research in the dry valleys has shown that biodiversity is lowest in the cryogenic cracks. So, when we walk across the soil, we specifically walk in the cryogenic cracks so that we are only harming the least diverse part of the community. As you can tell from the first photo, that means we don't walk in many straight lines!

Cryogenic cracks are not unique to the dry valleys of Antarctica. They are commonly found in cold places where permafrost underlies the soil, such as the Arctic tundra. They're even found on Mars, which is one piece of evidence that leads scientists to believe that there may be water on Mars.

New Outhouse

A helicopter delivered a package to F6 camp. It was our new outhouse!

At the camps in the dry valleys, there is no plumbing. All of our waste material has to be contained in barrels and buckets and shipped off the continent at the end of the season. We can't release it anywhere in the dry valleys, because it is a protected environment. Therefore, we use an outhouse where all of our waste is collected.

At F6, we had an old outhouse that was pretty small and rustic. There was a bucket with a seat that we used for solids. That was covered by an old garbage can lid. For liquids, boys stood outside and used a funnel in a barrel, and girls squatted over a tin can in the outhouse that was then poured into the barrel outside. Here's a shot of the old outhouse:
But the NEW outhouse is much more luxurious! It's bigger. There's two comfortable foam seats with real seat covers: one over the bucket for solids and one where girls can sit over a big funnel that leads to the can. There's a urinal inside for boys, so they don't have to stand outside. But that's not all! There's also hooks to hang up your coat, ventilation panels, and a sunroof! The plexiglass panels let in light, but also heat the outhouse like a greenhouse. Plus it's bigger, so there's more room to store the extra supplies and still be able to move around comfortably. We are very excited to have such a fancy new outhouse!

Here's a video tour of our fancy new outhouse.


Exciting times at F6!

Nunataks

Today I flew back to the camp at F6 on Lake Fryxell in Taylor Valley.

Because there were two stops we needed to make before dropping me at F6, I got to fly over some pretty cool scenery. Instead of coming in the mouth of Taylor Valley from the (frozen-over) sea ice, I flew from over the Asgard Range of mountains that border Taylor Valley on the north side. There are alpine glaciers that cover a lot of the area up there.

This is the view I had coming over the Asgard Range, most of which is covered by the glacier. Just beyond the mountain peaks in the foreground is Taylor Valley. (In the background of the photo are the Kukri Hills, which make up the southern border of Taylor Valley.)

There is a lot of land under the glacier, we just can't see it. However, some of the mountain peaks are tall enough to poke out of the glacier. These are called "nunataks". You can see an example of a nunatak on the right-hand side of the picture above. Nunataks are isolated from the rest of the land by the surrounding ice, which is how they get their name. "Nunatak" is an Inuit word that means "lonely peak". They are not created by the glacier, but were a part of the mountain range before the glacier was there. While organisms living on land below the glacier will probably be killed by the glacier, they may be able to survive for a long time on the nunatak. Scientists find all sorts of organisms living on nunataks in Antarctica, such as bacteria, lichens, and mites. So, even though nunataks are isolated, they are not uninhabited.

Back in Town

Friday evening I returned to McMurdo Station from Cape Royds. In Antarctic lingo, we call that going back to "Mactown." There, I met up with two more of my group members that have just arrived in Antarctica. Here we are, all three together!We will be a three-member team until early January, when Ross (our fourth member) arrives.

During my two days in town, I've been processing the samples I collected from F6 and Cape Royds. One of the things I have to do is clean the soil off of the moss I've been collecting, so that I can measure the nutrient content of the moss back in the U.S. To do this, I have to place the moss in a dish under the microscope:
I showed you before what patches of moss look like in the field. It looks like a piece of carpet, and it's hard to tell the individual plant stems apart. This is what a piece of that patch looks like through the microscope lens:The green parts you see are just a small part of the moss. Those are the leaves, which grow on a stem. Below all of those green tops are a large mass of brown rhizoids, that work like roots for keeping the moss in place and collecting nutrients. In this picture, the stems are bigger than the rhizoids, but in the moss I work with, there's a lot more rhizoids than stems. There's a lot of soil stuck in that tangle of rhizoids, and I have to wash all of that out. If I don't, when I take my nutrient measurements, I won't be able to tell the difference between what nutrients are in the moss versus the soil. It's very time-consuming, and requires a lot of patience!

Once the moss is clean, I put it in an oven (at a low temperature) to dry it out so that I can safely ship it back to the U.S. for analysis.

This is just one of the chores I've been doing since I've been in Mactown. It's been busy, because tomorrow I head back to F6 on Lake Fryxell for more field work!

[Photo credits: Moss diagram from http://www.botany.hawaii.edu]

The Wonders of Penguin Poo

Yesterday evening I left Lake Fryxell and flew to Cape Royds, one of the penguin rookeries on Ross Island.

While I am here, I will be measuring respiration from soil covered with penguin poo! When most soil organisms respire, they produce carbon dioxide (abbreviated CO₂). Humans do this when we breath, too. By measuring the amount of CO₂ coming out of the soil, we are measuring how much the soil organisms are respiring. Since penguin poo has a lot of nitrogen and phosphorus, I expect much more CO₂ to be respired from these soils than the dry valleys. (Just think about what you would do... if someone gave you a lot of yummy things to eat, you'd run around and be more active, and therefore respire more. The same thing happens for soil organisms!)

Here's a measurement being taken at the rookery. All the light-colored pink and tan stuff... that's penguin poo! The small machine down by the lake edge is what measures CO₂ coming out of the soil.

The penguins are very funny to be around. Many of them are very curious... just as curious as we are about them! Here's Adrian, who volunteered to help me with my measurements today. Who's studying who?