November 23, 2011: Windy Antarctica

Antarctica is the coldest, driest and windiest continent. Since moving camp to Conrow Glacier I’ve finally got to experience the winds. When first setting up camp we had a hard time putting up the Scott tent because the wind was so strong it kept blowing the tent out of our hands. The day after setting up camp we went out to set up a meteorological (met) station so it could record data for the two weeks we are at Conrow Glacier.

Kate next to our met station once we finished setting everything up. Anemometers are the black instruments at the end of the metal arms.

Our met station was 10 feet (~3 meters) high and had four anemometers for measuring wind speed at different heights above the ground, a sensor for measuring temperature and solar radiation. Measuring solar radiation, or sunlight, lets us know how sunny or cloudy it is on a given day. The anemometers showed that the maximum wind speed was approximately 32 mph, with a daily average of 20 to 25 mph. Temperature measurements give an average of -6° Celcius, meaning that it was relatively warm here at Conrow Glacier. Most days the wind came from the coast, but for a few days there was a wind coming from down valley, originating from the East Antarctic Ice Sheet. There have even been a few days where the wind is coming from Conrow Glacier. East, south and west!

November 26, 2011 : Like Mars

The McMurdo Dry Valleys are an excellent place to study terrestrial geology, but they can also be studied as an analog for Mars. Today the surface of Mars is very geologically active compared to other planets. We can see dust storms, observe the changing shape of the polar ice caps and even image ice sublimating (going straight from its solid state to a vapor) from the surface of the planet. Today Mars is a very cold and dry planet. So when we want to study the geologic processes active on Mars today the McMurdo Dry Valleys serve as an excellent analog because of their low precipitation rate and extreme cold temperatures.

Image of the surface of Mars, taken from the Viking 1 lander.

Image of Wright Valley, taken through my snow goggles to give everything an orange color.

On Thanksgiving Kate, Jen and I decided to walk down to the Onyx River. It flows through Wright Valley and is the longest river in Antarctica. Once we got down to the valley floor we spent some time watching the water flow in the river. It was nice to see something moving for a change. As we were getting up to leave we saw some dust devils form on the opposite side of the river. A dust devil is similar to a mini-tornado, but the winds do not have to be very strong and they are only able to pick up fine particles such as dust and sand. At first there was only one, but a few minutes later another dust devil formed. They only lasted for approximately 5 minutes before disappearing. The appearance of these dust devils gives another example of features found on Mars that have also been observed in the Dry Valleys.

Picture of Wright Valley and Onyx River, taken from the valley floor. Note the beautiful U-shape of the valley, indicating it has been carved by glaciers. Valleys cut by rivers are usually V-shaped.

Dust devil on opposite bank of Onyx River.

Dust devil filmed on Mars by the Mars Exploration Rover Spirit in 2005.

November 23, 2011 : Crazy Rocks

Rock weathering in the McMurdo Dry Valleys is stranger than the “normal” erosion we observe every day. Here at Conrow Glacier erosion is thought to result from a combination of processes. For instance, it is thought that snow sublimates and leaves behind salt that can break down rocks. It is easily seen when parts of the bottom of boulders erode away. Freeze-thaw weathering is important in the Dry Valleys and occurs when water seeps into rock fractures and alternately freezes and melts. When the water freezes it expands, making the fractures larger. Another common process is thermal stress weathering; when rocks get warm they expand and when they are cold they shrink. Eventually the continual expanding and contracting of a rock will cause it to crack.

Crazy dolerite that has been almost completely eroded in its middle. All that is left is a pillar in the center and its base.

Heart-shaped rock. It is a granite located in the second to last moraine at Conrow Glacier.

Large boulder that has been fractured along pre-existing joints. See orange notebook for scale.

November 14, 2011 : Move to Conrow Glacier

Today Kate, Jen and I packed up and moved camp to Conrow Glacier. We spent the morning packing up and a little after lunch a helicopter came to take us from Stocking Glacier in Taylor Valley to Conrow Glacier in Wright Valley. We rode in a Bell 212 helicopter, a large helicopter capable of carrying a lot of weight. Our helicopter had to make two trips. First, the helicopter picked up us and packed as much equipment as could fit in the vehicle with us (about 600 pounds). Then the helicopter had to go back to Stocking Glacier and pick up our sling with the tents and other equipment, weighing around 930 pounds. After the helicopter left we spent the rest of the day setting up camp.

Our Bell 212 flying away after dropping off our sling.

Stocking Glacier from a helicopter. You can see how it is shaped like a stocking you would hang on the mantle for Christmas

Conrow Glacier from our helicopter. Its shape at the terminus, or end of the glacier, is more diffuse compared to Stocking Glacier.

 

Stocking and Conrow glaciers are very different in shape. Stocking Glacier has a very steep cliff face with an ice apron at its terminus. Large blocks of ice fall off the end of the glacier and crash to the ground below creating the ice apron. Unlike Stocking, Conrow Glacier gently slopes down to the ground surface. It becomes difficult to differentiate between the end of the snow apron and the beginning of the glacial ice in Conrow Glacier. This difference is likely due to the wind patterns in this area of Wright Valley.

November 9, 2011 : Camp life in Antarctica

Camping in the Antarctic Dry Valleys is very different from a normal camping trip in the woods- no campgrounds here. We cleared an area of boulders and small rocks and then began to set up camp. We have two tents, a yellow Scott tent and a multi-colored Endurance tent. The Scott tent we are using today is basically the same tent used by the famous Antarctic explorer Robert Falcon Scott. Two people sleep in the Scott tent and the third person sleeps in the Endurance tent where we cook meals and hang out at the end of the day. 

Camp 1, located southeast of Stocking Glacier.

Camp 2, located northeast of Conrow Glacier.

Inside the Scott tent. Cots are on the left and right and the stove used for heat is straight ahead.

Kate cooks us dinner inside the Endurance tent.

We have several meals we make every week and then we have “special” meals that we’ll make every once in a while. For instance, we make spaghetti, veggie stir fry, and burritos almost every week. Our special meals include hamburgers and bagel pizzas. The food tastes delicious after spending a long day collecting samples and making measurements.

After dinner we listen to music (and dance around), talk and read books before bed. To get ready for the next work day we make sure to charge any science equipment using the generator. On special occasions, such as Thanksgiving, or when it has been a tough day working we will watch a movie on one of our computers. In the evenings when we are hanging out after dinner we turn the stoves on to heat up our tents. The average temperature at Conrow Glacier has been about -6° Celsius.

 

November 6, 2011 : Upside-down Moon!

When most of you look up at the Moon at night you see it’s nearside with dark and light patches. The dark patches are large deposits of basalt (the volcanic rocks you find in Hawaii). In the northern hemisphere these basalt patches appear to be concentrated near the top and left side of the Moon. When you can see the Moon clearly in the southern hemisphere it appears upside-down! The basalts are concentrated near the bottom and right side of the Moon (according to a northern hemisphere reference). This is because in the southern hemisphere you are basically standing upside down on Earth

Picture of the Moon over one of the Stocking Glacier recessional moraines. In this particular picture it is difficult to make out the light and dark patches.

  

November 5, 2011 : Glaciers: Moraines

We made it out to our first camp in the McMurdo Dry Valleys on November 3. The first day was spent making camp in Taylor Valley and since then we have been walking around the base of Stocking Glacier collecting samples from the terminal and recessional moraines deposited in front of the glacier. A moraine is a long narrow pile of rocks deposited at the end of a glacier as it melts away (see image below). Terminal moraines mark the farthest point a glacier flowed and recessional moraines mark the locations a glacier pauses during its retreat.

Diagram of a retreating glacier. Image shows terminal moraine and a recessional moraine. Other glacial features are labeled on diagram as well.

Picture of one of the recessional moraines at the end of Stocking Glacier. This moraine is the most obvious moraine because it has a clear concentration of large boulders compared to the surrounding areas.

 

Glacial moraines can be seen all over the world. Moraines occur in regions that have glaciers today and areas that used to have glaciers. Some good examples in New England include Long Island, NY and Cape Cod, MA. These two areas were formed from terminal moraines almost 21,000 years ago! These moraines in New England are much larger than the moraines we will be sampling in Antarctica. The moraines we are sampling at the base of Stocking Glacier are <1 km long while those in New England are 250-300 km.

: Illustration showing the location of terminal moraines near Rhode Island. Long Island, NY and Cape Cod, MA are both formed from large terminal moraines deposited during the Last Glacial Maximum.

First animal sighting!

The weather has been terrible here in McMurdo the last two days. Visibility was down and there were very high winds. As a result, all of the helicopter flights out to the camps have been pushed back. Since we had an extra day on our hands, Jen, Kate and I decided to go to the Ob(servation) Tube. It is a hole that has been drilled into the ice just outside of McMurdo. A shaft goes down through the ice and there is a little capsule to sit in at the bottom, below the ice and observe the aquatic wildlife. The Ob Tube is located next to several cracks in the ice where seals are likely to come up for air and rest.

Jen heading down into the Ob Tube.

Once we arrived at the Ob Tube we spotted a Weddell seal laying out on the ice. He did not move the entire time we were there. Then a few minutes later a skua flew by! They look like big brown seagulls. Apparently in McMurdo you have to be careful carrying food around. If a skua spots you carrying food he is going to try and steal it right out of your hands. 

Weddell seal laying out on the ice shelf.

Skua flying by.

Then it was my turn to head down into the Ob Tube. The observing area at the end of the tube is basically all windows. Near the bottom of one window I found a little fish hanging out. I was on the lookout for seals swimming by, but no luck. There were a bunch of fish swimming in the distance as well.

Tiny little fish near observation window.

View from bottom of Ob Tube. Lighter blue area in center of image is a crack in the sea ice where sunlight was penetrating though. I was keeping my eyes open for a seal here. Maybe next time.