Weather and Sea Ice
Sunday, 10 September 2000
It is amazing how quickly the days change. When I arrived
here a little over a week ago, it was dark when I began work in the morning.
Actually, the sky did not begin to lighten until around 8:00 A.M.
and the sunrise wasn't until after 10:00 A.M. The sun would set a
little before 4:00 P.M. and the sky was dark before I finished
work in the afternoon. Barely a week later there is light in the sky when I wake
up in the morning and I can watch the sunset after I finish work at 5:30. It
will not be too long before I will be sleeping through both sunrise and sunset,
and by the third week in October the sun will stop going down altogether.
McMurdo Station sits in a little valley right on the coast.
It is a somewhat protected position, although we do sit in the shadow of Mount
Erebus, the world's southernmost active volcano.
When the sun comes up in the mornings it rises behind Mt. Erebus, and there
is the most gentle light hitting the mountain range across the bay. It is
very subtle and difficult to photograph, but quite lovely. The Royal Society
Mountains (a portion of the Transantarctic mountain range) are bathed in pink.
The sound between us is not yet lit, so is a lovely shade of blue.
In the evenings the sun sets behind the Royal Society Mountains putting
them in silhouette against a red sky. Because the sun is traveling at such a
low angle, the sunsets last for hours.
There is a phenomenon down here called nacreous clouds. I do
not know if this is something which is indigenous to Antarctica, or to very cold
climates in general. I suspect it is as it has to do with ice crystals in the
sky and some cirrus cloud formations. The clouds look like mother of pearl with
many colors and lovely patterns. I saw a few of these last season and was very
impressed, but what I saw then cannot begin to compare with what I have seen
this year. I am guessing that it's because I am here earlier in the season when
the sun drops below the horizon and the temperatures are colder. The sky is
reminiscent of a science fiction movie, but I am seeing it with my own eyes. Of
course the photos don't begin to do it justice. It is truly breathtaking.
Last season when I was here we began doing renovations on
building 155, the main building in town which houses the galley, the store, the
barber shop, the ATM machine,
the television and radio stations, the library, etc. Down here whenever people
complain about things being hard or difficult the standard reply is, "Antarctica
— it's a harsh continent." It is a phrase you hear frequently in response
to many things. When there are no fresh vegetables for several months, or when
you have to work outside in severe weather conditions, or even when you can't
get the computer to work right, someone will invariably say, "It's a harsh
continent." One of the projects the winter crew had to do was to renovate our
galley. They did a beautiful job. We have all been joking about how McMurdo is
turning into a regular "Club Med" these days. Some things have really become
quite comfortable. Even the Coffee House is serving "smoothies" (from a frozen
base of course). Now when someone complains that the sauna is not hot enough,
you hear, "It's a harsh continent!"
In the big picture, however, Antarctica still is a harsh
continent. Storms can come up without warning. It is amazing how quickly the
weather can change. Last season, I saw a few storms, but nothing like what I
have heard stories about. I decided to come down earlier this year in the hopes
of experiencing just one of those storms. So far this year the weather has been
pretty mild, although at times rather cold. I have worked outside several days
this week, including one day when the wind–chill dropped down to
–67°F. Surprisingly, when properly dressed, I was not too
uncomfortable. On Friday we had a small storm with winds of 33 knots which blew
a lot of snow into town.
There are still many dangers and we are constantly being
warned or trained for one thing or another. On Friday I had to attend Sea Ice
training. People began studying the behavior of sea ice in the 1950's after
Willy Williams, for whom our Williams Field is named, died when a crack formed
in the sea ice and the tractor he was driving fell through. Since that time they
have learned much about how sea ice behaves and no one else has died. There have
been a few accidents, but not too many, and all have survived. Anyone who has to
spend time out on the sea ice must go through training. We learn about where and
why cracks form in the ice, what shapes they will make and how to identify them.
We spent half a day in the classroom and then got into a Hagglund, a tracked
vehicle which is also amphibious, and went out on the ice to look for and test
various cracks.
If you think that driving over the sea ice is a smooth drive,
think again. It is a terribly bumpy ride. Several of us have large bruises from
being banged around inside the Hagglund. There are windows, but they get
terribly frosted up. You can scrape them, but the ice is hard and it is
difficult to get off the glass. It may take a good 10 minutes to scrape down,
and then will freeze again in under 60 seconds. The front cabin of the Hagglund
has some heat. The back section has no heat, and although you are out of the
wind, it is still uncomfortably cold. When we find a crack we stop and drill in
various areas to test the thickness of the ice. Unfortunately the weather was
very overcast, so the photos are not very clear. Shooting white snow on an
overcast day does not offer much contrast.
If a crack is less that 30 inches deep for more than 3 feet,
then we are forbidden to drive across it even in a tracked vehicle. We found
several cracks which were only 12 inches deep, but not very wide, and the ice on
either side of it quickly grew to thicknesses from 4 to 12 feet.
If you see seals on the sea ice, you can be sure that a crack
is nearby. The seals have to chew holes in the ice so that they can come up to
breathe and to get on top of the ice. Chewing through 6 to 10 feet of ice is
quite a job, so they will look for the thinnest ice to chew through. That, of
course, would be where the cracks are. Sure enough we found a few seals lying
on the ice and went over to investigate. They were not too concerned with our
presence. They looked at us, but did not bother to move. They are quite adorable.
As the weather can change without warning we never leave town
without survival bags. Each bag contains a tent, a sleeping bag, a shovel, ice
pick, food for 3 days, a small gas stove and several other things. It is pretty
bare necessities, but designed to keep you alive in a severe emergency. Our last
order of business for the day was to learn how to pitch and secure a tent on the
sea ice. As we were pitching our tents the weather did take a turn for the
worse. The wind picked up and things got very uncomfortably cold. Our fingers
were all aching before those tents were finished. But we got them up. We had to
use the G.P.S. system to get us back to town as the visibility out on the ice
had gotten so poor. All in all, it was an interesting day. I hope I never need
to use those emergency skills, but I am awfully glad to have had the opportunity.
There should be some exciting things coming up which will make use of our sea ice
training, but I will save that for future stories.
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