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Ancient Buried Ice in Antarctica

Hi Jackie! Brrr- we got cold just listening to your commentary and the wind audio :D Hope you are acclimating better now! You can do this!! My sixth graders just finished their geologic unit and are very interested in fossils and rock records so your expedition is very timely. They have a variety of questions for you and the team: Stephon: How is cemented ice formed compared to sedimentary rocks? Daniel and Lauren: which is better, sleeping in a trench or a tent? what's it like? Andrew: How do you recycle(in camp)? Meagan: Is it fun learning how to do your work? Sam: Is much of that area unexplored? Grant: How is your frostbite? Does it hurt? Shelby: How long has the glacier been retreating? Aaron: What's the coldest temperature right now there? Haley: How far down did you find the volcanic ash that is 4 million years old? Samantha: What kinds of materials keep you warm? Alan: How long before you can shower (if you are camping)? The class is learning a lot about glaciers and ice core drilling from your journals Jackie. We look forward to learning more !! Cheers, Lollie

Mon, 12/08/2008 - 16:40

Jacquelyn Hams

Hi Lollie and Grade 6,After reading this, I'll bet you are glad your stint was on a ship.
Dr. Marchant says that this is one of the windiest years he can remember, so I don't feel too wimpy!
I will answer some of the student questions here, but will leave some of the science questions for later, as we have just started drilling what may be the last hole of the season, and some of the information may change.
Daniel and Lauren: I have never slept in a trench, so I cannot which is better. I can tell you what it is like to sleep in a tent. We have cots in our tents because the ground is covered with boulders and rocks. The cot is layered with a thinsulate pad, then an air mattress and a sleeping bag, so it is quite comfortable.
Andrew: We recycle in camp just as in McMurdo, only on a smaller scale. We have large plastic bags to separate glass, plastic, cans, and burnables. The helicopter picks the bags up periodicaly and brings them to McMurdo. Everything is shipped off the continent of Antarctica for disposal.
Meagan: It is a lot of fun learning about the work that is being done. The team is very energetic and fun and they all love their work. Everyone has fun in spite of the cold.
Grant: Thanks for asking about my frostbite. I was lucky and I had frostnip which is not as serious and I am not having problems. I do not let my hands get too cold, however and I always have hand warmers in my pocket.
Aaron: The coldest temperature right now in Antarctica is at the South Pole. it is -32 C or -25.6 F. That is pretty cold.
Samantha: We are given ECW or Extreme Cold Weather Gear in New Zealand before we arrive on the ice. I wear non-cotton long underwear that is my own. I then layer with the ECW gear. The first layer is a heavy fleece black top and pants. That layer is followed by the wind pants that look like coveralls. Finally, the big red jacket and hat and gloves. You do stay warm, and the only problem areas I have are the hands and sometimes the feet. No other part of my body is cold. When I am hiking and moving around, nothing is cold.
Alan: I went 8 days without a shower. Dr. Marchant and the team have been out for over 30 days! It really is not noticeable in the cold.
Jacquelyn Hams
Los Angeles Valley College

Sat, 12/13/2008 - 17:11

Jacquelyn Hams

Dear Lollie and Grade 6 Redd School,Here are the answers to the other questions you asked.
Stephan: 

How is cemeted ice formed compared to sedimentary rock?
This is a great question.  As you know, many sedimentary rocks form as individual particles, or grains, are cemented together by some type of geological “glue”.  Commonly this “glue” can be clay, silica, or calcite.  In this case, the glue is ice.  Ice-cemented sediment isn’t a true sedimentary rock, but the ice holds the grains together just like clay in a sedimentary rock.
 

Sam: How much of Beacon Valley is explored? 
One of the interesting aspects of working in the Dry Valleys is that so much of it remains unexplored.  There still are places where no-one has walked before.  However, Beacon Valley has been a site of scientific interest for about 30 years, so much of the area has been studied – but very little of it is understood.  I would say that over the last 30 years, only about 25 people have worked on scientific problems in this valley. Dave and his team, however, routinely travel to remote areas (via helicopter) where few, if any, have ever walked.  It is an exciting region with the potential for exceptional discoveries with every step.
 

Shelly:  How long has Mullins Glacier been retreating?
This is a great question, and one that is a little difficult to answer.  From your readings, you may be inclined to think that glaciers retreat back up into mountainous areas.  But, they also retreat by a process called downwasting, where the front of the glacier remains in the same position but the whole glacier thins as surface ice is lost.  This is how Mullins Glacier is retreating today, and it has been doing so, ever slowly, for at least the last 8 to 10 million years. The ice is lost via sublimation, not by melting.  There have likely been minor episodes of ice expansion during this time period, but overall Mullins Glacier has been shrinking (thinning via sublimation) for millions of years.
 

Haley: How far down did you find volcanic ash that is 4 million years old? 
From your understanding of sedimentary rocks, and the law of superposition, you might think that to find a layer of ash 4 million years in age you’d have to dig to great depths. But, this is not the case in Beacon Valley.  Ash up to 8 million years in age occurs right at the ground surface.  The landscape, and glacier ice, are ancient. Dave likens them to museum pieces, frozen in place and time.  So, things like volcanic ash that fell on the surface millions of years ago remain there today. Some of the ash, of course, blows away.  But, ash that falls into deep polygon troughs may be protected from wind erosion.  The ash can remain in ancient polygon troughs for millions of years.  It is one of the things that makes Dave’s work possible in this, the coldest and driest region of the Dry Valleys proper.
 
 
Jacquelyn Hams
 
 
Los Angeles Valley College