Antarctica, Macabre and Sublime

We’d originally planned to stay in on Wednesday and analyze our results from previous trips. When we learned the forecast was for clouds, though, we realized it might be our last chance for a while to make good measurements, and headed out to the ice. Upon getting to our planned site, however, we found that the day was beautifully bright and sunny, with barely a hint of the “partly cloudy” the day’s forecast had promised.

SCIENCE INTERLUDE: Why, you may well ask, do we need cloudy days for our measurements? Here’s a series of pictures I took on Wednesday, showing the same patch of ice from different angles:

You can see that the amount of light reflecting from it is radically different depending on what direction you’re looking. If we tried to determine the amount of light reflecting from the surface, we’d get similarly variable results. So we need a cloudy day, when the light is diffused and comes in equally from all directions.

Given the weather, it was clear that the day was entirely inappropriate for taking measurements. Happily, that made it an ideal day for a hike. We parked the pisten bully on some multi-year sea ice near an outcropping called Turk’s Head and set off to explore.

Our first discovery was something that looked a bit like a rock sticking out above the ice, but upon closer inspection proved to be the frozen corpse of a small Weddell seal. A little more searching turned up two others. Below is an image of the third one, which shows evidence of having been scavenged, probably by large gull-like birds called skuas. (Skuas are a big problem around McMurdo in the summer, apparently–they’ll divebomb anyone who appears to be carrying food.)

I later learned that the head was probably removed by local biologists.

Bits of dead seal scattered around the ice nearby had protected the ice beneath them from the sun, leading to these strange structures with a small stem of shaded ice holding up a scrap of frozen skin.

Fungoid, alien forms gradually emerge from beneath a residue of death.

Rich and Steve deemed the loose scree on the side of Turk’s Head to be suitable for climbing, so up the slope we went.

Unsettlingly steep, but lots of fun nonetheless.

We ran around on the top for a while admiring the view and plummeting down snow slopes so I could practice stopping an uncontrolled slide using an ice axe (a useful life skill.)

Tent, Inaccessible, Big Razorback and Little Razorback islands. From here you can see that they are actually parts of the rim of an ancient volcanic caldera. They say it's extinct, but you can tell it's merely biding its time beneath the ice.

As we descended, the pressure ridges in the sea ice showed up beautifully in the low light of the sunset. Pressure ridges are formed, as the name suggests, when currents and winds press huge slabs of ice up against each other. The combination of pressure, wind, and sun creates these grotesque and fantastical forms–I’m a bit vague on the specific mechanisms.

Ominous eldritch being or Muppet?

The ice fog rolling in at sunset produced a sundog, a circular rainbow around the sun:

The sundog touches down in the ice fog around Tent Island.


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4 Responses to “Antarctica, Macabre and Sublime”

  1. Migrating « Psychroteuthis Says:

    […] Antarctica, Macabre and Sublime (more pics on Picasa.) […]

  2. Ramon Says:

    You know, I’ve seen people stop an uncontrolled fall with an ice axe all the time in movies. And never once did I wonder if they’d had to practice that skill beforehand.

    • psychroteuthis Says:

      It is fairly straightforward, but there are a few tricks to it. For instance, if you’re switchbacking up a hill (and you probably are if it’s so steep you might need to use the ice axe) then you want to hold the ice axe in your uphill hand. Also, you want to hold it so that when you fall, the pointy bit goes into the snow/dirt and not into, say, your leg.

  3. Sara S. Says:

    Are there ever earthquakes in Antarctica?

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