Archive for February, 2011

Disruptions

February 26, 2011

I am far behind on transcribing posts; I’ve been traveling around New Zealand, so Web access has been difficult to get.

Most of you have probably heard about the major quake that struck Christchurch on Tuesday. I was well away from it at the time, but since Christchurch is the “gateway to the Antarctic”, quite a few people from the US Antarctic Program were there when the quake struck. Most of them have been accounted for and are alive and well, although many of them have been left with nothing but the clothes on their backs, and several have hair-raising escape stories, including one person who apparently had to dig himself out of the wreckage of his hotel room and another who rappelled down the side of a building on bedsheets. The USAP personnel in Christchurch have been exceptionally helpful, starting up a makeshift refugee camp in the Clothing Distribution Center and adjoining flight terminal.

Meanwhile, down at McMurdo, the sea ice has broken out of the sound for the first time in a decade and a half (not because of the quake, it’s just coincidental.) Probably as a result, pieces of the ice shelf are breaking off. This may prove problematic, as the ice shelf is where the planes land to take people to and from the station. Right now the station staff are hurrying to move the road so that they’ll still be able to access the runway, in hopes that the summer crew still on station won’t be obligated to winter over.

So it’s exciting times at the USAP. Everyone’s thoughts are with the quake victims, of course, and with Christchurch as it struggles to rebuild.

I’m about to leave for a four-day hike, but I’ll be back in touch when I return.

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.

Cheers!”

Waiting For My Ship to Come In

February 3, 2011

The vessel is coming.

Every year, McMurdo—enormous Antarctic city that it is—uses far more supplies than it would be economical to bring down by plane. So once a year, at the end of the season when the sea ice is a bit more navigable, ships come in bearing fuel and other necessities. Food, materials, parts, T-shirts for the store, you name it. An icebreaker (the Oden, this year) makes a path for the resupply ships through the remaining sea ice near shore.

This is an enormous undertaking. The fuel tanker arrived a few days ago, shortly after we got back from the field, and the fuelies (e.g. the people tasked with moving fuel around and getting it where it’s needed) have been working long hours all week to get it offloaded.



The enormous fuel tanker looks into the midnight sun. Scott's hut is visible behind it, a little ways to the right of the No Smoking sign.

Tomorrow, or so I am given to understand, The Vessel is due to come in. I don’t know much about The Vessel (as it is universally known) except that it will be taking many of our ice cores back to the States, but I do know what effects it’s having on the town. Dozens (hundreds?) of temporary helpers from the U.S. Navy have arrived to help offload it. The town’s supply staff will be working practically nonstop. Some of the inessential functions of the station are essentially shut down for the week to ensure that everyone concentrates on the enormous task at hand. Big areas of the station are restricted or entirely off limits.

In the meantime, we’re still busy processing all our samples to get them onto the vessel (we cut up the ice cores in record time, actually) and making pictures of bubbles–which I ought to post about soon.

Bubbles!

Oh, by the way, the resupply ships dock at a pier that is made largely of ice—it’s just seawater pumped into the shape of a pier during the colder parts of the season, with a little bit of a framework (I think) to help it keep its shape. It’s several meters thick. Here they are blasting the edge off of it to get it ready for the tanker, which is visible in the background.

BOOM

Repost: Blue Ice Reconnaissance

February 3, 2011

Original post, called in on January 12, 2011. Click on the links beneath the photos for their accompanying Picasa albums. Thanks again to Jonathan Beall for the transcription!

“Hey folks. It’s been another beautiful, sunny day here in the Allan Hills. We mostly don’t seem to have any other sorts, although we did have a little cloud this evening. We also had some rain, a type of precipitation I did not expect to find out here. You see, melting snow for drinking water, cooking, and in fact just hanging around and breathing in our kitchen tent creates a lot of moisture which condenses on the ceiling and freezes. When the wind dies down, the sun warms up the tent and there’s a minor deluge.

From In the Endurance

Pouring melted snow into a thermos to keep it warm/liquid during the night. These thermoses are pretty excellent, actually--water poured in at 90C (the boiling point at this altitude) will still be hot the next morning. The orange color is not a filter or special effect, it's just what things look like inside the orange Endurance tent. Pictures look a little more natural in black and white, but I thought I should give you the full experience of being there and having your color sense altered.

Aside from that, it’s been a pretty exceptional day. We headed out on snowmobiles this morning to survey our field site. We covered about 30 kilometers all told, visiting several fields of blue ice and some rocky moraines sticking up above the ice field. (A moraine, for the non-glaciologists among you, is a pile of debris that a glacier plows up as it moves, pushing rock to its front and sides.)

It’s neat to be out here. You get the experience of being on the ice sheet, with snow and ice stretching out for miles, yet there’s still enough mountains and hills to make for interesting topography. The mountains are beautiful—in that stark, lifeless sort of way that Antarctic mountains are beautiful. The ice fields are mottled blue and white with patches of snow. Driving across them in the sunlight is kind of like driving across the cloud-flecked sky, except when you’re driving into the sun, when the whole thing turns to liquid silver stretching out to the horizon, with ripples like the ocean.

From First Day Out – Allan Hills

A little liquid silver on a small ice promontory. Also a good illustration of an Antarctic photographer's dilemma: how to tell your subjects apart? Fortunately Big Red comes with a nametag, so I can tell you (using the hi-res version of this photo) that Ruschle is on the left and Martin on the right.

I even stepped into a crevasse today. Too small to fall into, but large enough to be a good object lesson about the importance of watching where you step. So, that’s your moral for today.

From First Day Out – Allan Hills

The hole I made in the snow bridge over the crevasse.

Until tomorrow, signing off…”