Once again, we're back at Davis after some days 'in the field'.
Technically, I would be able to write an entry for the blog while we are out there, but it would be complicated: my laptop doesn't work very well in the cold, so I have to get it warm in my sleeping bag, and connect it to a bigger battery. Then I have to use a satellite telephone to send the email; the connection is too slow to send pictures, and sometimes drops out suddenly. And we're usually pretty tired - working outdoors all day and living in tents takes a lot of time and energy.
So really, it's just easier to wait 'til I get back to base, where I can use a computer in comfort, indoors, and have a good internet connection. Sometimes I have used email to communicate with my colleagues in Australia while in the field, but mostly we talk on the satellite telephone, or use it to send SMS messages.
It's hard to describe how big Antarctica is, and how empty: the place we were working last week is about 750 km from Davis, that's about the same as from Melbourne to Newcastle, in Australia!
You can download a map of this area from the AAD (pdf, 3.6 MB). Davis is at the top right of the map, and we were at Wilson Bluff, almost the furthest south bit of rock in this region, at 74.3 S, 66.8 E.
There were three of us on this trip: Nick and I were joined by Alex, who works with Nick at Geoscience Australia. They were going to Wilson Bluff to do maintenance on another GPS station, and I had a new job: to service a seismic station installed there several years ago by Anya, a colleague at the ANU. Her instrument has a sensor in the ground recording earthquakes from all over the world, which she uses to study the rocks underneath Antarctica.
It's always exciting to arrive at an instrument site: to see whether it's still working, and what effect the storms of the previous winters have had.
At Wilson Bluff, we got a nasty surprise: both sites were crippled. Their solar panels had been blown over, a wind generator had broken off its mast, cables were snapped and instrument cases filled with ice.
Oh dear... we had a couple of days hard work to repair everything, and when we left, both sites were working again, and made stronger than before. We hope they will survive the next winter!
Clearly, the weather can be pretty bad at Wilson Bluff, but we were lucky: one day with a bit of wind and snow, but mostly fine and sunny. Quite comfortable for living in tents, even though the temperature was 5 to 10 degrees below freezing. And we had time to go for a couple of walks in the evening, to enjoy this magnificent place. It's beautiful, but harsh and barren: we didn't see any plants or animals while we were there, just one tiny square centimetre of lichen.
After three days at Wilson Bluff, a CASA plane came and took us about 100 km to another site, called Dalton Corner.
A funny name for a mountain, but if you look on the map, you'll see that it's at the southern end of the Mawson Escarpment, a north-south chain of mountains about 100 km long. On their east side, the ice flows right up to the Mawson Escarpment, but on the west side, it's a spectacular long line of cliffs about 1000 m high.
At Dalton Corner, we have another GPS site, which we had to service. Here, the news was all good! We had lost contact with the instrument two years ago, so we didn't know if it was working or not, but when we arrived it was running exactly as it should be. I checked the data it had stored, and found that it had worked beautifully, turned itself off in the winter to save power, and on again in the spring when the sun returned, for the last two years, without anybody checking it!
Fantastic - it's a very nice feeling when equipment works correctly! So it wasn't much work to collect the data, upgrade some of the instruments, and replace the batteries with new ones.
After finishing our work here, a CASA came to give us the most marvellous ride home, northwards along the Mawson Escarpment, above the Lambert Glacier. This is the largest glacier in the world, about 80 km wide and 500 km long, an enormous river of ice, slowly draining 35 cubic km of the Antarctic ice sheet into the sea every year.
When you fly over it, it doesn't seem to be something that can move, but it creeps along at one or two metres per day, and where it turns corners or stretches over buried mountains the surface breaks into vast crevasse fields, gaping chasms big enough to drop a house into. Some areas are smooth snow; others are covered by streams of meltwater. It's all beautiful.
We had one more job to do before going back to base: the CASA stopped to refuel at Beaver Lake, and Alex, Nick and I raced up a hill to another GPS site, about 4.5 km away. At this one, we only had to remove all the instruments - it's not going to be used for another couple of years.
Three hours later we were back at the plane, pretty tired from a hard fast walk! Then a couple more hours flight, along the coast in gorgeous low evening sunlight.
Happy Australia Day,
Dan
