Turning ice into water

Text and pictures © 2006-2024 Guillaume Dargaud
Last updated on 2021/11/05

"Tonight's piss is tomorrow's Tang."    — An American astronaut.

Filling the melter

Left: The melter in the winter night, with Concordia in the background and smoke coming out of the power plant chimney on the right. The access ramp allows loading with the Caterpilar.

Right: Claire driving the Cat, loading the melter with fresh snow. In winter it's enough to load it once a week, but during summer there's not only an influx of people but also increased outside activity (more sweat !), thus more showers.

Just like everywhere else, water is crucial to life. The problem is that in Antarctica there is no drinking water (*). It's either sea water on the shore or frozen ice. We are sitting on top of 3.5km of water and there's not a single drop to drink ! On the shore the main technique is to desalinate the sea water, and inland we melt the snow. (*) this is not entirely true as there are sub-glacial lakes (such as Vostok) and sub-glacial rivers running the meltwater from the huge ice pressure away from the center to the coasts; the problem is that it's impractical to use as basically unreachable.

Left: Jean filling the snow melter, something that needs to be done several times a day in summer, otherwise the level drop down too much or the water heats up too much. The heating is provided directly by the power generator through pipes running at the bottom of the melter: we try to recycle heat as much as possible.

Right: Loading the melter in summer. For the winter we weren't sure that the Cat would operate in extreme cold, so we had a pile of shovels ready...

The melter is one of the crucial elements of the station. Its only purpose it to melt snow and produce water, if possible without wasting too much energy. If it fails we are left without water.

Left: Doing maintenance in the empty melter.

Right: Cleaning snow off a heat exchanger.

Left: Loading the melter in winter.

Water from the melter is actually too pure and needs some ions added to it, mainly sodium and calcium.

Water uses

Right: Claire holding a bucket to catch the dripping water while Jeff tightens up the pipes.

Left: Stef and Michel tightening the joins along the dripping water pipes, inside a double ceiling.

When we started the winterover, the main buildings of Concordia weren't operational yet. There was no heating, no electricity, no toilets and no running water. The last plane had already left and we were still sleeping in tents... The priority was to activate the generators and then heat the place so we could work better indoors. The day we sent water inside the pipes was hectic as there were many seals which had been forgotten to tighten.

Right: Jeff reporting on the status of the water distribution system.

Left: Jean monitoring the motopump sending water through the fire hose during a fire drill. The input water comes directly from a tank outside, which has water always maintained at warm temperature.

Right: Water being sprayed out the window during the fire drill, in other words a very expensive way to add some snow to Antarctica... The main problem with this outside tank method is that the pipes running from it are cold and if you stop the flow, the water freezes instantly.

It is interesting to note that toilets in Concordia don't use water. It's either outside in drums in summer, where it's left to freeze; or inside into an 'Incinolet' burner toilet.

Recycling

Right: Introducing the water recycling plant inside its container above the power plant (Photo Hubert Sinardet).

Left: Introducing the water recycling plant inside its container above the power plant (Photo Hubert Sinardet)

Melting snow works fine, but it requires a huge amount of energy from the generators, so as a way to save energy we use a recycling system designed for spaceships by the European Space Agency. The system is designed to eventually recycle everything (the so called 'dark water' which also contains toilet water), but only the 1st half was installed in 2005, so it would recycle only 'grey water', which means showers, kitchen but not toilets. Since we drink it, it made us feel slightly better...

Right: Stéphane fixing tubes in the water recycling plant.

Left: The map of the system and the filtering membranes in the background. The membranes are rolled inside the big green tubes.

Right: Michel Galland, Michel Munoz and Jeff checking the water network in the back of the Concordia power plant.

Left: Claire inside one of the water recycling tanks, cleaning goo off the inside.

Right: Claire passing one of many buckets of goo to Christophe from the inside of the tank. She started knee deep in goo and had some rain down on her head when she touched the ceiling.

Left: Cleaning goo off from the inside.

Right: An example showing the use of a fisheye lens to take a picture of a round object, in this case a duct opening (okay, this is not perfectly framed, but you get the point). Claire inside a water recycling tanks, cleaning the mud from the bottom. See and compare the similar straightened image farther down.

Above: Claire's head sticking out of one of the water recycling tanks, with Christophe helping her out to clean the tank from all the goo accumulated after 6 months of activity. This system recycles only what we call 'grey' water, that is any water what doesn't contain urine or feces (aka 'black' water). In a year or so another part of the system will be added to recycle also the black water and then the station will be self sufficient. And indeed the designer of this system is the European Space Agency and they develop it with space missions in mind, where the recycling will need to be complete. The door is hidden behind Christophe.

Left: Claire performing her regular tests on the water to ensure its quality.

Right: Claire (with hair) performing chemical analysis of the recycled water.

Left: Claire (without hair) purging one of the tanks of the water recycling plant.

Right: Fine tuning the settings on this experimental system designed by the European Space Agency.

Right: he 'mud' tank below the stairs, where all the urine and leftover water from the water recycling process gets dumped (pipe clearly visible). It freezes in place in the cardboard box which needs to be replaced about every other week.

Melter bath

Right: Michel looking down the melter, with one trapdoor raised, under the light of a powerful projector.

Left: Michel watching from the trapdoor while the other Michel and Claire are inside cleaning the melter to get it ready to become a Jacuzzi.

Right: Yours truly, taking a bath in the snow melter... and freezing my head off at the same time !

Left: Jeff and Michel taking a bath.

Right: Doing laps inside the melter/jacuzzi.

Left: Yes, we are insane and we enjoy every minute of it. Outside temperature: -65°C, requires special survival gear. Water temperature: way too hot to stay inside more than a minute, requires bikini. The only question left to solve is: how do you get in and how do you get out without freezing your butts off ?!?

Right: The water on the skin freezes instantly when you get out.

Left: Claire enjoying a vivid snow friction.

Rodriguez well

Right: Raising a casing tube.

Left: Lowering the casing tube for the construction of a Rodriguez well.

Right: Getting the casing tube in position.

So melting snow and recycling the water works well, but could there be a better method, on that doesn't involve moving tons of snow with a Cat ? Actually there is. The americans facing the same problem at the Amundsen-Scott base of South Pole invented the technique of the 'Rodriguez well', named after its inventor. Simply said, it melts the ice underground and pumps it up. Obviously the devil is in the details. You have to go deep enough that the ice is actually waterproof: too near the surface and it's still dense snow and not ice.

Left: Lowering the casing tube into a drilled hole in order to create a Rodriguez well, Dome C, Antarctica. HDR image created from several scans of the same slide in order to compensate for bright snow.

So the technique is to drill a 30m deep hole in the ice using the same technique as for the glaciology projects and encase the upper part so that it doesn't collapse. Lower either a heating resistor or a recirculation pipe (reheated by the generator) and a pump inside the hole, heat up until water starts melting and pump some of it away, always leaving some water so that the hole enlarges itself as it goes down. Once it gets too deep (after about 7 years at SP), the pump won't work well and a new hole is started. The americans use the abandoned wells as sewers, but we bring all our wastes back to the shore. More info here.

Right: Attaching casing tubes to each others.

Here in the summer of 2005, Alain is just getting started on the construction of the well.

Left: Getting another tube ready until the wanted depth is reached.

As a bonus you can find micro-meteorites at the bottom since they sink when the ice they fell in long ago gets melted. Just scoop them out (easier said than done, a special robot had to be designed to do just that).

Lakes

Right: A glacier drying up and turning into small streams and freshwater lakes in the Dry Valleys, Antarctica

With all this snow and ice, you'd expect that some of it would melt and form rivers and lakes. Well, some does, but not as you'd expect. The main reason is that it's just too cold. Even in summer on the warmest places of Antarctica, only minutes amount of ice manages to melt. One of the few places where this melting occurs is in the Dry Valleys where small streams manage to form some strange lakes such as lake Vanda, a hypersaline lake with a perpetual frozen surface. This high salinity, ten times that of sea water, ensures that the lake never freezes completely even in winter as the salt lowers the freezing temperature of water. It's probably the saltiest lake on Earth. The bottom of the lake is actually a balmy 23°C. Life in the lake is limited to bacteria and tiny algaes.

There are actually a few short rivers in Antarctica, the longest being the Onyx River which flows down one of those Dry Valleys and feed lake Vanda during the summer months. It is only about 30km long and does not reach the Ross Sea but goes under the Wright glacier which blocks the bottom of the valley.

Left: Example of a water tube inside a glacier, as seen on the Glacier Noir.

Now the Onyx River is a rare example of a 'classic' river with a surface flow, but there are many subglacial flows. Glaciers anywhere have water running at their bottom, with the flow forming paths and even large rivers when they collect farther downstream. Depending on the underlying geology they can form large 'lakes' in depressions, those lakes being permanently covered with kilometers of ice. Here the combination of high pressure from the weight of the ice and geothermal flow from the center of the Earth manages to keep the waters in liquid form.

Lake Vostok is the largest of all subglacial lakes and has an interesting history. As the Russians were trying to reach the geomagnetic pole during the first IGY (International Geophysical Year) back in 1957, they came across a remarquably flat area, even flatter than the already depressingly flat Antarctic plateau. After driving for 250km on it they stopped before starting up on new hills and started drilling. It was the first deep drilling, way before Epica and it was also long before sounding and radar imagery showed the presence of a 250km lake underneath nearly 3km of ice.

So the russians drilled and went back in time with increasingly older ice going back about 400 thousand years but they stopped short of breaking into the lake. There are many reasons. One reason is that the last few meters is not ice from surface snow but from refrozen lake water and as such it is wet and soft and may get the drill stuck. Another reason is that it is expected to find some form of life in the lake but it is difficult to avoid contaminating the lake from the drill or the drilling fluid (tons of special fluid poured into the drilled hole to keep its pressure high to keep it from closing).

Finally in 2012 the lake was breached, and the pressure in the hole was dropped while the drill was quickly pulled up, getting the lake waters into the hole to refreeze for 600 meters. Now work is underway to drill again this frozen water and analyze it. So far results are inconclusive as most DNA found seems to be from external contamination in the lab. We'll know soon. If I remember to update this page.

One of the interesting first findings is that the lake waters are highly oxygenated, which may seem counterintuitive for a closed system that never sees sunlight (remember that oxygen comes from photosynthesis of CO₂ by plants). The reason is that the snow that accumulates on the surface contains oxygen which stays trapped in the ice until, after hundred of thousands of years, it joins and melts and accumulates into the lake. It also implies that there's isn't much respiration going on in the lake which doesn't bode well for the discovery of strange life forms...

The brits are trying to use a different drilling technique to reach the waters of Lake Ellsworth, another of those large and deep subglacial lakes: they used boiled water which is both sterile and used to drill the hole by simply melting the ice.

And yet another lake is lake Vida, similar to lake Vanda: permanently covered by 20 meters of ice the temperature of its water is -13°C while remaining liquid due to its salinity being 6 times that of sea water. The thickness of the ice doesn't let any light through and there's no oxygen. The waters from the lake have been separated from the outside by this thick layer of ice for at least 3000 years. Despite all that there's a great variety of bacteria which a very slow metabolism evolved to use the iron dissolved in the water while producing H₂, which in turns feed other bacteria in this enclosed ecosystem.

As you see from those very different examples of lakes, life finds a way.