It's an unusually cloudy day here at Lake Joyce and the weather is making it feel cold. We have a morning of drilling ahead of us, and an afternoon of diving – a busy schedule! However, I have a few minutes now to respond to some really wonderful questions from Natomas Charter School students in Mr. Bae's class!
Ice melting into a strange, hollow shape.
There were LOTS of really good questions about the colors and shapes of the ice on Lake Joyce – about why there are different colors and shapes of ice, and how the ice will change as it gets warmer. I'll answer these in one go:
The ice on the lake is quite variable and complex. Generally, it's about 4 meters thick, and that will not change anytime soon. In some places, the ice is milky white and very reflective of light where there are more grains of sediment in it. In other places, the ice is clear and a little bit blue, indicating a lack of sediment (good for drilling!) and it's like looking down through a window, although it's still too thick to see water below. In some places the ice is brown where there is a lot of sediment. Sometimes sediment is blown by the wind onto the top of the lake and forms drifts. These absorb more energy from the sun, get warm, and melt the ice underneath, and the sediment sinks through the ice and forms a pocket, that can then be covered over with ice on top. Then when it's a little warmer, the upper edges of the ice melt and the wind blows it into different shapes where it freezes again. The result is a twisted jumble of weird shapes in some parts of the lake. Great for hide and seek, not so good for Marco Polo!
Jumble of ice on Lake Joyce shaped by cycles of freezing, thawing and wind.
Ice and sediment on Lake Joyce.
Some other questions that came up are as follows:
We saw the picture of the Taylor Glacier, and we wanted to know how tall it is in feet from the surface of Lake Joyce to the top of the glacier.
That's a great question, but unfortunately, I don't have a way to measure that for you. The glacier is enormous, and we actually can't see most of it from where we are. When we look at the edge of the glacier that borders the lake, we only see the end of one small arm of it. The rest of the glacier is miles and miles long. Here's a photo of Megan next to the face of the glacier for scale. She's 5'1".
Megan in front of Taylor Glacier.
We wanted to know about the helicopter resupply in one of your recent posts. Do you already know what will come in the resupply, or expect it to come with the supplies you need?
The helicopter resupply was planned... sort of! We told them what foods we wanted based on what we were running low on, so we knew what to expect. In a couple of cases, we got substitutions for what they no longer have at McMurdo. (This inspired a lengthy debate over whether Slim Jims are a substitute for real beef jerky. The conclusion: NO.) However, we didn't know when the helicopter was coming and it caught us off guard, but that wasn't a big deal.
We read your article from October 31st, and we want to know how long it took to set up camp and begin working. Were you guys working faster or slower than you expected. See you in December!
We arrived at Lake Joyce at about 10 p.m. and it took us until about 3 or 4 in the morning to get to the stage of having tents set up and things tied down enough to go to bed. It was a long night! Over the course of the next 2-3 days, we got much more settled and set up. I think it took us about the amount of time we were expecting. The lack of wind that night really helped a lot!
Thanks for your great questions! I hope to hear from Natomas Charter School again soon – I miss you all!
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