mlml logo

nsf logo Powered by Blogger.
Thursday, October 4, 2007: Wicked Cold
Nick and I took a hike this evening up Observation Hill behind McMurdo Station, and in addition to taking in an amazing view and reflecting on the fragility of the human condition, we learned an important lesson about electronics in the cold: they don't work so great.


It's very easy to lose perspective and orientation in Antarctica, both because the air is so clear that distant objects are clearly visible, and because those geographical objects are frequently gianormous. It's also easy to get slammed with a total whiteout blizzard in a matter of minutes. In any case, the global positioning system is an invaluable tool to know where you are and how far you have to go to get back into a warm bed at the station. My personal GPS doesn't have any predefined maps or waypoints for the Antarctic region, so I brought it along on a hike up Ob Hill to record its position. When I got the top however, the device barely powered up, couldn't connect to satilites, and after showing some strange streaked messages on the LCD screen, shutdown in less than a minute.

Pretty much any type of battery performs poorly at temperatures around -23 degrees celsius (-10 fahrenheit), and the old alkaline batteries (unfortunately non-rechargable) from the last trip I took with the GPS wimped out fast. Good thing we could see our way home!

In contrast, the cross memorializing the last expedition led by Robert Scott (all members perished, most a mere 11 miles from a supply depot after a several hundred mile trek to the south pole and back) which was erected in 1903 was in remarkably fresh condition, preserved by the cold dry environment. Wind has eroded the wood a few millimeters, but the paint used to inscribe a message was tougher and is now raised up from the wood.

A couple seconds after snapping these shots the batteries in my camera died as well, so no more photos for today!

In addition to draining batteries, extreme cold can explode capacitors, cause microchips and clocks to lose timing, and freeze up motors; doesn't sound like a welcome environment for SCINI, which is packed with all these electronics components. Fortunately, SCINI will be submerged in liquid salt water, the temperature of which averages around -2 degrees celsius (29 fahrenheit; the salt lowers the freezing temperature of water). If the water was any colder it would freeze, so we are assured it won't get so cold our electronics would be seriously harmed. We do have to watch out for fresh water crystallizing on our camera or around the waterproof o-rings, but this temperature actually has some real advantages: most electronics waste less power when running at low temperatures, and the excellent cooling means we don't have to worry about overheating.

So SCINI will be happier in these near freezing waters, but I think our divers will be wishing they were high and dry in their Extreme Cold Weather (ECW) gear on the surface: water wicks away heat much more efficiently than air, so they'll be chilly even inside insulated dry suits.

Post a Comment!

Subscribe to Post Comments [Atom]

<< Home
Subscribe to Posts [Atom]

This material is based on work supported by the National Science Foundation under Grant No. ANT-0619622 ( Any opinions, findings and conclusions or recommendations expressed in this material are those of the authors and do not necessarily reflect the views of the National Science Foundation.