Sydney Observatory’s Geoff Sims is on his way back from the South Pole

Return from Ridge A
Geoff Sims

Arctic landscape

We have recently returned from 6 days / 5 nights camping on the high Antarctic plateau at a place known as Ridge A: the driest and possibly coldest place on Earth. Our mission was to refuel and refurbish an existing robotic observatory (the Plateau Observatory; PLATO), which supplies power and communications to a 0.6 m terahertz telescope (the High Elevation Antarctic Terahertz telescope; HEAT).

Ridge A
After around a week of weather delays at the South Pole, our Twin Otter pilots were finally given the go-ahead to fly us to this remote location. Although 25 knot winds were forecast, the previous week’s experience had shown us that the winds were typically overestimated, and hence this was not considered to pose any threat.

Around 4 hours after departing the South Pole, we landed at Ridge A. It turns out that the weather forecasts were spot on: -40 degrees C and 20-25 knot winds. If you believe in the “windchill factor”, this pushes temperatures down to near -60 degrees C. A preliminary review of data from an automated weather station at nearby Dome A suggests that this may possibly be the worst (windiest) weather in recorded history! Just our luck.

Geoff Sims at Ridge A
After ripping apart some failed electronic components from the modules (which were sent back via the same Twin Otter to the South Pole for repair), we quickly went into “survival mode”, huddling around in a tent with hot drinks provided to us by our mountaineer/guide.

For the remainder of our time at Ridge A, the winds died down but were still stronger than usual, making work a lot harder than anticipated. Thankfully, we had two large “work tents” designed to shield us from the wind and perhaps even provide a (relatively) warm work environment. The temperatures at Ridge A varied from approximately -45 C at local midnight, to -35 C at local midday (keep in mind the Sun never sets). A few hours after local midday, our tent was usually around freezing (0 degrees C), which meant we could comfortably work in just thin glove liners.
Working on batteries at  Ridge A

We were only meant to spend a couple of nights in the field, but once again weather delays meant we were trapped at Ridge A for much longer than anticipated. Although the extra time was utilised (and in fact proved to be a blessing given the harsh working conditions), nothing can describe the relief we felt on the 6th day when we received word that a Twin Otter was on its way to take us home. The same aircraft would deploy the remainder of our team in the field in a “tag team” like fashion..

I am writing this blog entry from the South Pole, where -25 degrees C has never felt so warm. The past 6 weeks in Antarctica has been an incredible experience. We have slept in an igloo at the foot of an active volcano; watched seals and penguins dance on the ice; spent a couple of weeks at the geographic South Pole; and of course camped at the driest, coldest, and one of the most remote and inhospitable places on Earth: Ridge A. The last of our team are due to return from the Ridge A campsite later tonight. We will all begin the journey back to Sydney tomorrow.

Detailed daily accounts of our adventures as well as view many more photographs and time lapse videos, are available for viewing at our blog.


(Geoff is one the wonderful casual staff that work at the Observatory while he is completing his Ph.D)

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