Posts Tagged ‘transect’

Cruising Down the Ice Line

March 31, 2011

Original audio post.

Hi! It’s been an excellent and extremely productive couple of days. Yesterday the wind was much lower, so we went out to take cores from our various measurement sites. By the end of the day it was dead calm, and the subjective temperature had jumped by about forty degrees Fahrenheit. I don’t what the actual temperature was, but it felt like summer had suddenly arrived. We took 16 cores, dragged our chairs outside to have dinner in the sun, and went for a walk to enjoy the weather–hence the lack of blog post.

I feel like I talk about the weather a lot, but it really does have a huge effect on both our ability to do science and our general experience of this place. Without wind, there’s nothing to make noise except us and the ice. Last night we could hear the cracking beneath us very clearly. Actually, it doesn’t exactly go “crack”–it makes two different noises that Martin described today as “voomf” and “bloop.” I’m not sure quite what causes these different noises, but perhaps I’ll find out.

The calm also makes it easier to overheat in one’s cold-weather gear, especially when drilling ice cores, which is a labor-intensive job. I wrote a couple of limericks about the day’s activities.

Limerick One:
A day spent in the Allan Hills coring
Could never be useless or boring
The reward for our troubles
Is a bounty of bubbles
Tiny worlds we’ll spend hours exploring

Limerick two:
The Antarctic’s mercurial mood
Demands a relaxed attitude.
Though the morning’s harsh storm
Needs three coats to keep warm
By six, you’ll be more comfortable nude.

So. Today the weather was very similar to yesterday, light wind in the morning falling off to nothing in the afternoon. We retraced our footsteps from yesterday, taking albedo measurements at each site. Sunny weather isn’t ideal for that, but you can correct for the direction of the light, and we didn’t want to risk waiting for a cloudy, calm day that never came.

Snowmobiles and science equipment.

We managed to get all the measurements done by five, so now we’re hanging around camp waiting for dinner (we take turns being Cook for a Day) and sunning ourselves. Sunning yourself must be done with care in the Antarctic, of course, since the ozone hole is just above us, and the sun would be exceedingly bright even without it.

Ah, I forgot to mention–while Ruschle and I were making [albedo] measurements, Mel and Martin were making maps of the cracks in the ice, using the box-and-camera method I described the other day. [It's] now christened the Ice Fracture Observatory, or IFO. They randomized the location of their measurements by the again exceedingly scientific method of turning around three times, taking fives steps, then throwing a glove in the air and taking a picture wherever it landed.

Our randomization procedure.

I am excited to see what tomorrow will bring. We might hike over the hill and do reconaissance on the glacier on the other side. We might make measurements of snow microstructure. We might spend some time investigating the weird, inexplicable features we’ve take to calling “crevasse blisters.” For that matter, we might spend all day in sleeping bags again, hiding from the howling winds.

By the way, I’m not much for self-promotion, but I do think it’s really cool that, thanks to the wonders of modern satellite phone technology, I can give you day-by-day updates of what we’re doing. If you happen to know of anyone else who would also find it cool, I encourage you to tell them about it. Anyway, thanks for listening! ‘Till next time, as my Swiss-German-speaking colleagues would say, [word I cannot spell but which I am assured is the German version of 'ciao'.]

Complex Scientific Equipment

March 29, 2011

Original audio post. Thanks to Lori for the transcription!

Hey! Well, this morning’s weather was pretty unpleasant, although we weren’t sure why it seemed quite so bad. It goes to show how much your points of reference have changed when you find yourself saying “It’s only -15 Celsius with 10-knot winds. Why does it seem so cold?”

So, anyway, we stuck close to camp. Martin and I put together a very sophisticated scientific instrument, which might appear to the uninitiated to be a cardboard box with a hole cut in the bottom.

I transport the device to the field as Ruschle looks on. Photo by Martin.

This allowed us to take photographs of the cracks in the blue ice without the picture being washed out by bright sunlight. Upending the box box on the ice and taking pictures through the hole gave us images in deep translucent blue with a delicate tracery of dark cracks. We’ll use these pictures to try and quantify the effects of cracks on the amount of reflective light.

The cracks as seen under the box.

The weather improved in the afternoon, enough for us to go out and identify sites to measure. I don’t think I mentioned yesterday exactly what we’re looking for. As the ice flows, it moves into the region where wind can scour away the upper layers. So as you walk along the line of flow, you start in an area where the surface is still snow. Then you reach an area where the surface snow has been scoured away by the wind to expose dense old snow from years past (which, as you may recall, is called firn.) Walking further, you reach bubbly ice, and finally dense old blue ice. We are trying to measure along that same line of flow to get measurements from each type of snow and ice.

So, we marked the lines with the bamboo flags that are ubiquitous around McMurdo, and perhaps we’ll get to go back tomorrow and actually measure.

I’ve been concentrating a lot on the science we’re doing here because it’s pretty exciting. But I haven’t talked much about day to day life in camp. The Scott tents alone are worth a whole post, so I’ll try to talk more about that in coming days.

Oh, and we saw a skua!

A different skua, circling over Icestock hoping someone will drop their sandwich.

Skuas are the local scavenger birds. They look like a big brown seagull and like to dive-bomb people carrying food. This one was probably a bit lost. There’s not much to eat out here. But, it was the first living thing besides ourselves we’ve seen in days, so it was pretty interesting. Anyway, until tomorrow, cheers.


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