Posts Tagged ‘antarctica’

Other people talk about ice!

June 25, 2011

I’ve been trying to do more with this blog than just write text and post it—WordPress offers a wide variety of features, and blogging is at its best when it’s part of a larger ecosystem rather than just one person talking in isolation. So I’ve been adding links to the blogroll. Allow me to present a few here:

From a Glacier’s Perspective offers detailed descriptions of glacier retreat around the world, with each post focusing on a different glacier. This post describes how a glacial feature called ogives can be used to help measure glacier velocity. (Ogives are “ripples” in the glacier that form due to the influence of icefalls: the area of ice that happens to be going over the icefall during the summer melt season melts faster than the ice around it, leaving a trough that then moves down the glacier.)

The IceBridge Blog recounts news from NASA’s IceBridge Campaign. The aerial surveys of IceBridge use a variety of instruments–lasers, radar, even a gravimeter–to survey the Earth’s ice. The information gathered from IceBridge will “bridge” the gap between IceSAT-1, which stopped taking data in 2009, and IceSAT-2, which is scheduled for launch in 2016. The blog includes both pretty pictures of icy landscapes and discussions of the science behind the work, such as this post on how airborne gravimetry can tell us about the shape of the land below water and ice.

For those of you wanting to see more of Antarctica (one of my favorite continents!) there’s the “Landsat Image Mosaic of Antarctica (LIMA)” which allows you to pan and zoom all over the continent. Anthony Powell’s photography shows the place on a slightly more intimate scale, mostly around McMurdo and including some justly famed timelapse films. Or Maria Coryell-Martin’s Expeditionary Art captures both the Antarctic and the Arctic, capturing the feel of the icy realms in a way photographs sometimes can’t.

I’ll be adding more as time goes along! In particular, I want to find some good resources on ice elsewhere in the solar system, which is a fascinating subject I haven’t even gone into yet.

The Voyage of the Endurance

June 11, 2011

Hey guys! I wrote you a song! It’s about the epic tale of survival that resulted from Shackleton’s attempted Trans-Antarctic Expedition; I used this website as a reference for some of the events, or you could read Shackleton’s own book on the experience, South. Be sure to check out the pictures, which are widely and deservedly regarded as the best part of the book.

Sung to the tune of (The Bonnie Ship) The Diamond.

The Voyage of the Endurance

‘Twas early in the century
The world prepared for war
But Shackleton intended the Antarctic to explore.
Some men sail for profit
Some sail for renown
But this one sailed for Science and the glory of the Crown.

Through the icebergs that clash, through the great waves that roll,
The mighty ship Endurance went a-sailing for the Pole.

The whalermen had warned them
That the ice would be severe
They were still above the Circle when the first floes did appear
Still bravely they sailed southward
But soon they were beset
Imprisoned in the heaving ice, but not defeated yet

Through the icebergs…

They whiled away the winter
Drifting ‘cross the Weddell Sea
When finally the sun arose, they thought they’d soon be free
But the mounting pressure of the ice
Was more than she could bear
In just days the stout Endurance was crushed beyond repair

Through the icebergs…

They loaded up the lifeboats
With provisions piled high
They watched her sink beneath the ice as, helpless, they stood by
The men camped on an icefloe
Let it take them where it would
It brought them near an island before breaking up for good.

Through the icebergs…

The isle was cold and barren
Inhospitable to man
So Shackleton devised another daring rescue plan.
He’d sail eight hundred miles
‘Cross the world’s most stormy sea
To the whalers on South Georgia he would make his earnest plea.

Through the icebergs…

A thousand times the pounding waves
Near sank the tiny boat
They lost most of their gear and food, yet somehow stayed afloat
When the party reached South Georgia
Thirst-tormented and sore
They realized the whaler-camp was on the further shore.

Through the icebergs…

They scaled the craggy mountains
And crossed crevasses deep
They stumbled into whaler-camp half-crazed from lack of sleep
The whalers were astonished
When these strange men came in view
Soon Shackleton secured a ship to rescue all his crew

Through the icebergs…

Let Shackleton’s Antarctic fame
For centuries survive
For with all their trials and troubles, every man came back alive!

A Field Scientist’s Work is Never Done

April 7, 2011

Original audio post.

Today’s science fell a bit flat, at least on my end. Ruschle and I went out to re-take some albedo measurements, but were frustrated by rapidly-changing cloud conditions that confused the instrument.

Ruschle covers the Sun so I can photograph the clouds around it, in an effort to compensate for their effects; eventually we just gave up.

Mel and Martin had better luck making snow measurements and taking samples. Right now, Martin is sitting behind me with his makeshift lab, pouring diethyl phthalate into snow samples to preserve them. We’ve been having a little trouble getting the stuff cold enough to set, but that’s another post, I think.

Anyway, I figured I’d talk a little more about the rhythms of life in camp. Life in any camp seems to be defined by its chores, so I’ll start with those. Thinking about chores, actually, I was surprised at how few I could come up with. Perhaps that’s because a lot of chores at normal camps involve cleaning things, and we happen to be living in a place with essentially zero dirt.

Responsibilities begin in the morning, when whoever slept with the satellite phone (it has to be kept warm, so it’ll work when it’s needed) calls McMurdo to let them know we’re still OK. Every field camp does this check-in. It’s a sort of failsafe, in case something disastrous happens and we aren’t able to contact anyone to call for help.

Whoever’s cooking breakfast–or sometimes whoever’s in the kitchen tent first–collects a bucket of snow from outside to melt for water. Melting snow is probably the most constant and time-consuming chore. All the water for cooking, drinking, dishwashing, and other miscellaneous uses must be melted in the big pot on the propane stove. Notably, bathing is not really on the list of uses. Living in unheated tents means that getting wet is more or less courting hypothermia, so we mostly do without. I’m sure there are ways to manage it [bathing], but for three weeks, in a place without dirt, we think we can get away with it.

The water-melting pot, which was in near-constant use when we were in the tent.

We hold an informal meeting after breakfast to decide, mostly based on the weather, what to do with the day. If we’re going out, we need to take the covers off the snow machines and inspect them before heading out to the field to do science. Coming back, we re-fuel and re-cover the snow machines. Without the covers, the engine compartments fill with drifted snow.

Snowmachines, neatly put away.

The cook for the day (tomorrow, that’s me) starts dinner while everyone else puts away the scientific instruments. (I’m thinking I might make some kind of Malaysian-style curry.) More snow is melted–again, usually by the Cook for the Day. Someone might sweep the kitchen, if it’s filled up with drifted snow again. Snow is kind of our equivalent of dirt, but it’s much less bothersome, since it generally evaporates if you leave it long enough. Still, when it accumulates in the kitchen, it becomes somewhat irritating.

Supplementary audio post.

Hey, sorry–I think my last post got cut off when the satellite phone went out. Somewhere around where I was talking about how it’s irritating when the kitchen fills up with drifted snow. I’m actually rather surprised that the satphone hasn’t cut out mid-post before now. Unfortunately the WordPress voice-post function is a bit primitive; the only option is to call, leave a post, and hang up. You can’t really edit it afterwards. So, I won’t try to re-record the whole post this time, since I was mostly finished anyway. After dinner, pretty much all that’s left to be done is to wash the dishes and decide who’s going to sleep with the satphone. So, uh, it’s about time for bed here, so I will bid you all goodnight and talk to you soon. ‘Bye.

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’.]

Great Scott!

March 30, 2011

Original audio post.

I mentioned Scott tents yesterday, and, since this morning dawned with 25-knot winds, I spent a lot of time contemplating the interior of mine today, cozied up in my sleeping bag. So, I thought I’d say a bit more about them.

Our three Scott tents.

Scott tents look rather like a child’s drawing of a tent at first glance. It’s nothing like the complex geometric curves of the tents you see marketed to backpackers nowadays; it’s a simple pyramid, four triangular sides sloping steeply to a pointy top. And most of them–most of the tents, that is–are bright canary yellow. I don’t know if the original version of the tent actually used by Scott was this color. It would seem terribly incongruous with the tragedy of their polar journey, Scott and his men dying slowly in a cheerfully sunshine-yellow tent.

Anyway. The setup process for a Scott tent is likewise simple, at least in theory. The edges of the pyramid are supported by four legs, which are joined together at the top. To put up the tent, simply stand it up and pull the legs away from each other until the walls are taut, then stake down the edges and guylines. This process becomes somewhat more complicated in windy conditions, as the rest of my team found out.

Once you’ve managed to stop the tent from blowing over, you can weight the edges with snow and put in the floor.

Now comes the tricky business of actually getting into the tent. The Scott tents are double-walled, which helps with insulation and prevents the kind of condensation-based indoor rainstorms we’ve been having in our kitchen tent. The entrance consists of two fabric tubes, one attached to the outside wall and one to the inside. The ends of the tubes can be cinched closed with drawstrings to keep the wind [and, just as importantly, drifting snow] out.

So, to get in, you first find the toggle for the outer drawstring, pull it out over the snow-encrusted string, wrestle the end of the tube open, crawl in, get the edge of the tube caught on your hat, trip over your boots, find the drawstring for the inner fabric tube, repeat the whole process, and finally fall into the tent with the outer tube caught on your boot and the inner one still lovingly wrapped around your shoulders.

Mel and Martin insist that this process is simplicity itself, and I am making a fuss about nothing. I think perhaps they have some weird arcane bond with their tents that I just don’t understand.

Mel, master of the Scott tent tube entry. Photo by Ruschle.

Don’t get me wrong–I do like the Scott tent. My tent is a snug home, and it contains my wonderful two-foot-thick down sleeping bag. Indeed, I think I’ll head there now. So, ’til tomorrow, ciao!

Ruschle happy in her down sleeping bag. These bags are so thick and fluffy that it is difficult to tell whether someone is actually sleeping in one until you peer into the face port. Picture by Mel.

You can string a clothesline inside the tent for drying your wet clothes--useful and decorative! Photo by Mel.

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.

Farewell, McMurdo

February 14, 2011

And so my time here ends; I’ll be boarding a C-17 early this afternoon to head to Christchurch. I’ve still got plenty of posts to transcribe and photos to upload, so keep looking out for updates. Right now I’m just running around taking care of numerous small errands that have to be done before I leave.

I’ll leave you with a few nice pictures I took around 4:30 AM during a bout of insomnia the other night:

From Early morning McMurdo

Vessel 2: The Evolution

February 12, 2011

The fuel tanker was pretty much done with its duties here as of a few days ago, but it ran into some minor issues when it tried to actually leave. Last year’s ice pier had broken free of its moorings and drifted out in front of the ship. They had to send some people out to attach cables and retrieve it:

People in survival suits ('Mustang suits' designed to allow a human to survive even in frigid Antarctic waters) attaching cables to the old pier.

The icebreaker Oden escorted the tanker out the next day.

The Oden escorts the tanker out.

Shortly afterward, the resupply vessel–which had been waiting a few miles out, past the edge of the sea ice–came in.

The BBC EMS. Apparently it is quite hard, these days, to find container ships small enough to fit McMurdo's harbor.

The people on station who deal with Stuff have been working around the clock for the last week to get everything off the vessel and reload it with the things that go back to the States. First the folks in supply jobs offloaded what was on the boat–food, parts for vehicles, new equipment, things to sell in the store, more food, and so on. Large areas of the station were roped off as staging areas for all this stuff while people got it where it needed to go.

A central staging area, right outside the Galley.

A thousand people eat a lot of food in one year.

A chart of the off-limits areas, modified slightly by dorm residents.

Then other groups of people swung into gear to get things back onto the vessel–science samples going back to the States (including some of ours!) and all the waste generated by the station in the past year, which will be recycled or incinerated as appropriate. Supposedly they’re done, or close to done, and the vessel will leave this evening, and everything can go back to normal (or as normal as it gets around here.) We’ll see.

My friend Jessie has a great post about the vessel with photos from alternate perspectives and some time-lapse videos of the whole process. Check it out!

Repost: The Snow Device

February 8, 2011

Original post, called in on January 14, 2011. Transcription thanks to Jonathan Beall.

(Sorry it’s taking me so long to put these up, by the way. Believe it or not, adding photos is the most time-consuming part of the process. Maybe I need to work on my methods.)

“Well, the wind is blowing just about as hard today as it did yesterday, but a helpful meteorologist at McMurdo told us that things are only going to get worse over the weekend, so we figured we had better make the most of it. We headed out on snowmobiles into the ice field to choose a new place to take measurements. We can’t actually make albedo measurements when the wind is this strong because blowing snow interferes with them. But we can select good sites to measure, which saves us time later on. Once we get a calm enough day, we’ll jump on our snow machines and spend it running around to different sites with our albedo measuring device. (I made a post about this instrument, the ASD, some time last year. If I had internet access, I’d link to it, but since I don’t perhaps some helpful person will do so in the comments. [A couple mentions, but I don’t see a post all about it.–Jonathan] [He’s right, I misremembered. Sorry! I’ll have to make one. — me]) We marked a site and took an ice core or three, and then went home for lunch.

In the afternoon, we tested out Martin’s device for measuring snow surface areas, which he made himself. It’s a sort of framework meant to be inserted into the snow. Then you dig the snow out of it to make a pit and take a picture of the wall of the pit using near-infrared light.

Ruschle, Mel and Martin working on the pit.

Snow grains of different sizes reflect different amounts of near-infrared light. They reflect different amounts of other light too, but the differences are easier to see in the near infrared. It’s a little bit of a simplification to say that the amount of reflected light tells you the grain size. It really tells you the surface area, because it tells you how many surfaces the light has bounced off before it reaches the camera. Once you’ve taken that picture, you dig a second one, leaving just a thin wall of snow, and shine a light through that wall to see how much gets through. This lets you calculate the density of the snow.

Snow structures.

It also happens to be beautiful. The different layers in the snow make delicate strips, shading from light to dark, depending on the time of year they were deposited, the weather when the snow fell, and various other things.

So, that’s what we were trying to do. However, things didn’t go quite as planned. We soon discovered that the snow here is much harder than the snow in the Alps, and we couldn’t insert the frame without damaging the snow we wanted to measure. Finally, we figured out that we could drill holes in the snow with our auger, which allowed us to set up the device with relative ease, although it still took a lot of hard shoveling to dig out the pit. And then, at some point, as we tried to get everything set up, we made the unwelcome discovery that Martin’s supplier for frame connectors had been somewhat mistaken about their tolerance for cold, and the frame snapped in half.

A broken fitting.

And of course, remember, that we’re doing all this in twenty-knot winds. But we finally managed to get everything set up, we took our measurements, and we went home feeling like scientific heroes. We got to take an item off the list of tasks that Ruschle wrote up for us, so we’re all feeling pretty good about ourselves.

The wind meant that we had to put a tarp over the site to prevent everything from being covered with fine drifted snow.

It’s supposed to snow tonight. It should be an interesting weekend. Until then, ciao.”

Repost: Cracks and Bubbles

February 8, 2011

Original post, called in on January 13, 2011. Thanks once again to Jonathan Beall for the transcription!

“Hi. Today was a quiet day. Well, in terms of activity. It was a quiet day in terms of activity because it was a noisy day in terms of wind. We had a good day of spirited scientific discussions in the tent instead. We were mostly discussing bubbles and their contribution to the amount of light reflected from ice, or its albedo.

Bubbles are awesome.

Ice is very transparent. Light can travel a long way before it gets absorbed. If there are no bubbles in the ice, most light will just travel straight through, and the albedo will be low. If there are bubbles, though, light can hit the bubbles and bounce away in a different direction. A lot of the light that goes into the ice will end up bouncing right back out, which is why bubbly ice has a higher albedo than clear ice. Ice in glaciers and on ice sheets, like where we are, has lots of bubbles because it’s formed from compressed snow. The spaces between snowflakes at the surface will turn into bubbles as the snow is squeezed into ice and a small amount of the air remains behind as bubbles form.

Complex bubble shapes are partly a result of the complex shapes in the snow crystals that formed them.

We also talked about cracks in the ice, which can increase the albedo just like bubbles do. The blue ice here has lots of cracks in it, mostly quite thin. We think they form partly because the ice is cracking as it moves, and partly because, as the top of the ice erodes away from the constant wind, the ice lower down is no longer under as much pressure, and it expands creating more cracks.

Cracks in the ice (picture taken using the Crack Box, an invention I'll explain in a later post)

We actually put on our parkas and went out to look at the ice near camp to see how the cracks behaved and to figure how we might account for them in our measurements. We probably looked a little silly lying face down on the ice and wriggling along the ice like seals, but then science is frequently a little silly; that’s one of the reasons I like it.

Another incident of science being silly.