Polar Passport

A Day in a PMV

It's been a busy few days.

On Friday we installed one GPS receiver at Wewak airport, and arranged batteries and transport for the other sites.

The equipment here is quite similar to what we were installing in Antarctica: a GPS receiver and antenna, powered by batteries and a solar panel. But here the antenna is on a tripod, not bolted to the ground like in Antarctica, because it only has to stand a few days, and because we are measuring the horizontal movement of the earth, and not the vertical (it's hard to measure the height of a tripod accurately enough to measure vertical positions). And we don't need to transfer the data
by satellite here - we just download it from the receiver every day or two.

On Saturday we made a trip along the inland road east from Wewak about 120 km, to the town of Angoram, on the Sepik River. We installed two more sets of equipment on the way, in Angoram and the village of Tring, both on survey markers that have been measured several times in previous years. We leave the equipment in a small tent to shelter it from the Sun and rain, and ask the local people to take care of it until we come back again.

The sites are left to make measurements for four days, but today we went back to check them. When we don't have all the gear to carry (each site weighs about 80 kg in total), we don't need to have our own vehicle. I prefer to travel by PMV, or 'Private Motor Vehicle', which are the private transport services operating all over Papua New Guinea. They vary from small vans in the towns, to trucks in the countryside, and 4WD vehicles for the mountain areas with rough roads and river crossings. It's a good way to travel and talk with the local people, and see where they are going and what they're doing.

Today our PMV had bad luck, with several flat tyres to be changed and fixed along the way, but we checked both sites, which were operating normally. Due to the travel delays, we got back to Wewak after dark, but the apologetic driver dropped us at our door. And it was nice coming back through the hills at dusk - the road deserted compared to daytime, the smokey smell of cooking and the glow of small fires in the jungle across across the valley, at huts invisible in the darkness.

Better luck next time,

Dan

Looking Up

As the summer is ending, the Sun is now below the horizon for about eight hours per day. I can hardly believe that just two weeks ago, when I was in the Grove Mountains, the sun just touched the horizon, and we had 24 hour daylight. But that was 500 km further south, and the seasons move quickly!

So we have a real dark night again now, and when the sky is clear the stars are wonderful. We've even seen some faint auroras. But recently I was thrilled to see the Davis LIDAR working.

LIDAR stands for "Light Detection and Ranging", which is the same as RADAR, except that it uses light instead of radio waves. That means it can look for different things: radar can detect bigger heavier objects, like planes, or rain; lidar can study the air itself, how cold it is and how much wind there is.

It is particularly interesting to measure the temperature of the atmosphere high above us, because that is where we expect to see some of the effects of global climate change. As greenhouse gases make the lower atmosphere warmer, they also make the higher atmosphere colder. So the lidar will help scientists test their predictions of climate change. You can read more about it on the AAD website.

The lidar is one of many interesting science studies being done at Davis, but the reason I wanted to write about it is that it looks so cool!

Photo by Mark Tell, courtesy AAD.

When it's running, a bright green laser points straight up into the sky. It looks like a real light sabre, or an enormous beanstalk. And it goes up and up and up... it makes measurements up to almost 100 km altitude, but when you look up, it just disappears into the distance, where the stars are.

Happy stargazing,

Dan

The Tent

For me, one of the most important symbols of Antarctica is the "Polar Pyramid" tent. The design has hardly changed in 100 years - a double skin for warmth, a strong pyramid shape with a pole at each corner, and a circular tube door that can be tied shut. They are proven as strong, safe and reasonably comfortable in the worst conditions, and are used by almost every country conducting research expeditions in Antarctica.

I just added up all the days I've spent in these tents over the years, and it comes to 36 weeks in total! So I feel right at home when I crawl inside and get into my sleeping bag.

The reason it's such a powerful symbol to me, is that the tent allows people to enter this enormous wilderness and survive. Smaller than a station or a hut, it provides only the minimum necessary shelter and comfort, and has no impact on the landscape.

Inside a tent, you still feel the cold, and hear the sounds of Antarctica. Its small size highlights the contrast between the vast inhospitable environment and the tiny human presence.

Imagine a flight from Davis Station to our most recent campsite, in the Grove Mountains: after taking off from the ice runway, you fly south towards a flat white horizon, leaving behind the coast, liquid water, and the life in the sea and the heated buildings.

For two hours you pass over nothing but ice and snow, blown into drifts that show the prevailing wind direction, but otherwise featureless and untracked.

Finally the mountains appear over the horizon, specks of black between the white disc below and the blue dome of the sky.

When you reach the mountains, it's a fairytale landscape: smooth rock faces hundreds of metres high, ice-carved spires forcing the glaciers to divert around them. And even though the Sun is shining, it's -15°C and the continuous wind that blows across the ice is funnelling between the mountains and blowing clouds of drifting snow 20 m into the air. You see nothing living.

But there, on a sheltered patch of snow beside one of the smaller mountains, there is a tent: a small angular speck, cheerful red and yellow in this world of white ice, blue sky and dark rock. And inside is a spark of life: two people in sleeping bags, warmth, food and friendship. The contrast is awe-inspiring - we can live and work here, but we are aliens here just as much as we are on the Moon.

A quick word about our trip to the Grove Mountains: after a delay at Davis due to bad weather, the planned trip was reduced to two people, Alex and me, leaving behind Nick and two other who were hoping to join us to help with the work and enjoy the spectacular mountains. A pity they couldn't all come, but we always have to adapt to the weather...

We had a couple of days hard work; Alex maintaining a GPS site, and I removing a seismic installation, both of which were last visited two years ago.

It's a spectacular place to work, surrounded by a magical landscape of steep mountains and ice, but it was also the coldest and windiest place we've been this summer, and I used my warm down jacket and thicker 'winter' sleeping bag for the first time.

After working late nights to get the jobs finished, the weather got worse and we had to wait another day before the CASA could fly from Davis to bring us home. We used it catch up on our sleep - Alex went out once to check his GPS site, but I actually stayed in my sleeping bag for 36 hours!

Alex is also writing a blog about his time in Antarctica, which includes some nice pictures of the Grove Mountains.

Goodnight from back at Davis,

Enderby Land

I spent the last few days far from here; camping at Mt Riiser-Larsen, in Enderby Land, about 1000 km west of Davis.

We flew there in the CASA planes; after leaving Davis we headed across the sea. It was wonderful to look down on the patterns of ice in the water, made by winds and currents.

After two and a half hours of flying, we arrived at another Australian base, Mawson, to refuel and pick up a couple of passengers. It's a beautiful place: the station is built on a rock perched between the ice sheet and the sea, and the plane landed near the Framnes Mountains, jagged ridges of rock poking through the ice.

From there, we flew west for two more hours, over hundreds of kilometres of smooth ice sheet, enormous glaciers flowing into the frozen sea, barren islands of rock surrounded by ice or ocean, and sharp mountain ranges extending to the horizon. Antarctica is wild and beautiful almost everywhere you look at it, but from an aeroplane you can appreciate how enormous and bleak it is...magnificent!

We landed on a frozen lake, unloaded our equipment, and looked for a place to camp. One of the CASA's stayed with us, while the other flew further along the coast to the Japanese station, Syowa, where one of our colleagues had some work to do. We used a sled to carry our tents and food to the shore of the lake, while the pilots, Dan (not me!) and Troy, tied the plane to the ice, in case there was a storm while we were there. We also had an AAD field officer with us, Mick from Mawson.

We put up our tents on the snow not far from the plane, with a great view of Mt Riiser-Larsen on the other side of the lake, and made a place among the rocks to use as a kitchen - usually it's not too cold to eat outside, and the view is much nicer than inside a tent!

Like at the Bunger Hills, our job here was to install a GPS receiver, to measure how the land of Antarctica is moving. Nick and I did that together over the next two days.

While we were working, the other guys did a couple of long walks, and came back in the evening to cook dinner.

Cooking can take a long time in Antarctica, when you have to melt you water from snow, and cook on a small camping stove, so having Mick, Dan and Troy to help us meant that Nick and I could work several more hours each day. It makes a big difference to how much we can do - thanks guys!

The GPS system has an antenna which is bolted to the rock, and protected by a plastic dome so it doesn't get covered in snow in the winter. Solar panels provide the electricity, and all the batteries and instruments are inside an insulated box, to keep warm. Every day, a computer in the box uses a satellite telephone to send the GPS data back to Australia. It was working perfectly when we left... I hope it stays that way for the next few years!

Yesterday, our work was finished and we flew all the way back to Davis, stopping again at Mawson to drop Mick back there and refuel the plane. Late yesterday evening we were back at base, heated up leftovers from dinner, and had a good shower! It seems like a very short trip, but we worked hard all the time, and did everything we planned to.

This summer's field work is going well!

Already preparing for the next field trip,

Dan

The Bunger Hills

Finally, we've started our work!

Last week I was in the Bunger Hills, an area of rocky hills not covered by snow or ice, about 20 km across. It's one of the largest ice-free areas in Antarctica, so it's called an 'oasis', where there are some lakes and a few mosses growing on land. It's between two of Australia's stations: about 1000 km east of Davis, and 500 km west of Casey. I'll try to post a map soon, with all these places. Not many people visit there, but the AAD has four small fibreglass huts, which they call "Edgeworth David Base", where we stayed.

We flew there in a CASA aircraft, with all our gear and several hundred kilograms of science equipment, and landed on a frozen lake in front of the base.

I call it a lake, because it's fresh water underneath the ice, but one side of the lake is a glacier, which is floating on the sea. The glacier goes up and down with the tide, and so does the lake, and the ice on top. So to walk from the plane to the huts on land, we had to cross the 'tide crack', where the ice moves against the land. Not difficult or dangerous, but there are some pools of water where you could get your feet wet. You can see it in the picture below.

At the left of this photo you can see the frozen lake, and the CASA plane that took us to the Bunger Hills. Between the plane and the land, you can see the 'tide crack' On land, you can see the four small huts (called 'apples') of Edgeworth David Base, and then on the right is the GPS equipment that Nick and I installed. You can see the solar panels, and the wind generator, which we hope will power the instrument all through winter.

Photo credit: Dan Colbourne (CASA pilot).

There were five of us working there: Nick and I were installing surveying equipment, Pat and Krystyna were collecting moss samples, and Mel is a "Field Training Officer" who works for the AAD, and was there to make sure everything was done safely.

Ill be working with Nick for the next couple of months. He's from Geoscience Australia, and I'm from the ANU, but we do similar work, so it makes sense to cooperate for the field work. In the Bunger Hills we installed an instrument for GA, and the next place will be for ANU. Nick is also keeping a blog about his trip to Antarctica.

We installed a GPS receiver, which we hope will operate there continuously, 24 hours a day, 365 days a year, for several years.

Like the GPS some people use bushwalking, or in their car, this one uses signals from satellites to measure its position on the ground. But it's more precise than normal GPS's: with a normal one, you can get your location accurate to about 10 m. That's good enough for walking or driving, but we need better accuracy: this one can give us the location to within 1 cm!

With that precision, we can study the movement of the Earth's tectonic plates, and also how Antarctica moves because of changes in the amount of ice there. That is my main interest here, and I'll write more about it later.

The GPS receiver is powered by six big batteries (like car batteries, but special ones for the cold), which are charged by solar panels in the summer, and a wind generator in the winter (when there isn't any Sun). It sends the measurements back to Australia by Iridium satellite telephone.

We celebrated Christmas while we were there: we had a few decorations in the hut, cooked a huge meal, and opened presents from home. A Perfect Antarctic Christmas!

Merry Christmas,

Dan

Welcome to the blog!

Over the next few months, I'll try to show you what it's like to work as a scientist in Antarctica. I'll tell you about the whole process: the preparation, travel, food, and daily work. If you want to know something special, just post a comment on the blog and ask.

I'm still in Australia, enjoying the hot weather, but getting excited about the summer ahead.

Dan