May 31, 2006, The Sandy Site
May 31, 2006, The Sandy Site
Jun 3 2006, 12:59 AM
Group: TREC Team
Joined: 12-April 06
Member No.: 25
High Temperature: - 11 degrees Celsius
Low Temperatuer: -26 degrees Celsius
The Sandy Site
Today I had a chance to check out some of the other research going on in the camp.
Bob was my tour guide for the morning. We were going to go to “Sandy Site”. Sandy Site was named after a graduate student who was doing her snow and ice experiments at this location last year. It is about a 20 minute snowmobile ride from camp.
Bob first explained some safety tips for riding snowmobiles. I learned how to turn on the snowmobile and shift gears. I also learned that is important to stand up on the snowmobile and rock the snowmobile from side to side before you start your trip to loosen any parts that might have frozen together during the night. Bob was a good instructor. The most important tip he gave me was to literally follow his snowmobile tracks. We only wanted to make one set of tracks in case we got lost. If we got lost, we could turn around and follow the track back to camp. What a smart idea. It was like leaving a trail of bread crumbs. Instead of crumbs, we were leaving a snowmobile track.
The ride out to Sandy Site was awesome. We left camp and rode on the skiway (the runway for the plane). It was very smooth so the snowmobiles went fast. At the end of the skiway, we made a right turn and followed the snowmobile tracks over small bumps until we reached our destination.
As soon as we arrived, Zoe was pulling out an ice core sample from 76 meters below the surface of the ice sheet. What perfect timing! The ice cores will be sent back to the United States so Zoe can examine the structure of them.
Can you see the ice core? How long do you think it is? 1 meter or 3 meters long?
Here is a picture of the drill that is used to collect an ice core sample.
Sometimes, the ice core will break and you will get a chip. The chip is very brittle. It will break easily. Can you see the air bubbles trapped in the ice chip? These bubbles contain the air from many, many years ago. By extracting the gas from these bubbles, scientists can learn about what Earth's atmosphere was like back then.
An ice chip from an ice core
Here is an experiment for you to do. The next time you have a piece of cake, take a straw and stick it into the top of the cake about 1 centimeter. When you lift up the straw, you should have a piece of the cake stuck in your straw. Remove the piece of cake (or get a new straw) and do it again. You should now have a piece of the cake that is a little closer to the bottom of the cake.
This experiment is very similar to drilling an ice core. The cake is like the ice sheet that we are on. The straw is like the ice core drill that pulls up cylinders of ice ranging in size from 1 meter to 4 meters long. The drill first gets ice core samples from the top of the ice sheet. The type of drill in the photograph can go to depths of about 300 meters. Other types of drills are used to go deeper into the ice sheet.
As soon as Zoe was finished, it was Mark’s turn to take his measurements. Mark is studying the air that is "flowing" in the snow beneath the surface of the ice sheet. To study the air "flowing" in the snow, Mark sticks a tube that looks like a fire hose into the ice core hole. He lowers it down to a certain depth and then inflates it. It traps the air deep in the hole. He then turns on a pump and sucks up the air that was deep within the ice sheet. You may have noticed that I put quotation marks around the word "flowing". The air beneath the snow doesn't flow like it does in our atmosphere. It moves by something called "diffusion". It is like what happens when a small drop of food coloring is dropped in a cup of water. The food coloring starts to spread throughout the water. The air trapped in the gaps between the snow moves in a similar way.
Today, Mark observed that air is still flowing through the snow at 76 meters below the surface. He also observed that the amount of carbon dioxide gas at a depth of 76 meters below the surface was lower than the amount of carbon dioxide gas currently in our atmosphere. Mark will continue to check the gases deep into the hole until he finds that air is no longer "flowing" through the snow.
A third scientist, Xavier, from France, was also at Sandy Site. He is measuring the amount of mercury that is in the air flowing through the snow. It was neat seeing how all three people worked well together.
Arctic Fact of the Day: The 4th International Polar Year will take place in 2007 – 2008.
|NSF Acknowledgment & Disclaimer||Time is now: 23rd May 2017 - 10:39 AM|