Several years ago, I had a watch with a barometer in it - presumably designed for people who ski a lot, and want to know how much they've gone up and down in a day. I forgot about it completely the one time I went snowboarding with it on, and mostly used it to time how fast lifts went, and to try to figure out which airlines had the best air pressure at cruising altitude. I never made notes, but I vaguely remember that ANA kept the pressure equivalent to being just below 2000m above sea level. Singapore Airlines were 100-200m higher, and budget airlines went up to about 2300m equivalent. The flight we took on SKY from Santiago to Lima on Boxing Day went to about 750 millibars, or 2350m above sea level, according to the free app that I downloaded on my phone.
Which makes one think: what happens when the place you land is higher than the cabin pressure? Does the airline only pressurise the plane to that level, or do they have do let air out before they can open the doors? This is relevant because San Pedro de Atacama is not only a literal oasis in the driest desert on earth, but also around 2450m above sea level, so the air there is very much like being on a plane, all the time. Apart from the smell of the digestive systems of your fellow passengers, and the crying baby in the row behind you, but you get what I'm trying to say, hopefully. The humidity is negligible: maybe as much as 30% on what passes for a damp day there, and water boils at around 92 degrees C, so it's hard to make a good cup of tea, and everything dries in a heartbeat. When you get out of the shower everything evaporates and it's remarkably cold for a few minutes; similarly any small spills in the kitchen dry rock-hard and have to be chiselled off the counter unless you keep a hawk-like eye on everything. The dew point is well below zero, too, so unless there's dry ice or liquid nitrogen in your drink there isn't any condensation. It does make it very easy to survive with minimal gear, though: you can hand-wash anything, even thick wool socks, in the evening and have them ready to wear again by dawn - and if you're used to Singapore's humidity then it's nothing short of magical. The amount of moisturiser we went through was unbelievable.
Actually, pretty much everything about the Atacama desert is magical. The first night we were there we sat under the stars and watched meteors stream through the heavens (we only saw three, but they were pretty spectacular). We quickly decided that it was sensible to stay indoors during the heat of the day and only go outside in the afternoon, and then only with lots of water and sunscreen.
The Big Red Truck, the Tulor pre-Columbian settlement, and sunset
After coming back from Pucón, where we realised a little too late in that a car would be useful, we booked a massive pickup truck to pick up at the airport in Calama, and cancelled our hotel transfer. It had air conditioning and four wheel drive, and was absolutely enormous, although I managed to parallel-park it first go the one time I needed to.
There's something about the light and the wide open spaces that's impossible to capture on camera. I decided to go for B&W, with a red filter (or, rather, what my trusty Fuji X100S says that does to a digital picture) to cut out the haze of the dust and darken the skies the day we climbed the Pukará de Quitor, which seems to have worked pretty well.
Chile is, at least to my limited understanding, geologically a pile of rocks that have been pushed up by the Nazca plate subducting under the South American plate. The most obvious result of this is the Andes themselves, but westwards of that there's the Intermediate Depression and then the Chilean Coastal Range of mountains. The Atacama is part of this depression, bordered on both east and west by higher mountains, which means it's very unusual for any kind of moisture to make its way over from either the Atlantic or Pacific. Everybody tells you it hasn't rained for over 400 years there, but that's not strictly true: most parts get a few millimetres of precipitation (dew, snow, and rain) per year, although there are weather stations that have never recorded any rainfall.
We went on one full-day trip up to the Lagunas Altiplanicas and to the Atacama salt flats. Again, not having read the guidebooks carefully in advance, we were a bit surprised by the number of times our ears popped driving up to the lakes, and even more to find that we were around 4200m above sea level when we reached the lakes. The highest I'd ever been before that was the summit of Mount Kinabalu at a mere 4095m: here we were quietly driving along with absolutely enormous mountains rising miles above us - actually some of the highest in the Andes, hitting over 6000m. The wildlife up there is very interesting: we saw nesting Tagua Cornuda by Laguna Minique, and some random vicuña just hanging out grazing.
Back down (over a mile down) to the salt flats, we found Andean flamingoes almost close enough to touch. The landscape is totally alien: encrusted with salt and looking as hostile to life as anything I've ever seen, but apparently there are small brine shrimp and other small crustaceans living there. Enough to support a lot of flamingoes, anyway. I wanted to taste the water to see how salty it was but Susan sensibly stopped me. Note: that's now three species of flamingoes we've seen in two months, and Susan's videos are now featured on the Flamingo Specialist Group's Facebook page.
The Valle de la Muerte, or Valley of Death, is apparently a misnomer: it's supposed to be the Valley of Mars, because it's just around the corner from the Valley of the Moon. If you're driving from San Pedro, then it's really badly signposted: there's a tiny sign that you can't see until you've gone past it, and the next turn is miles away. We managed to find it by taking the next turn, though, and (although we probably shouldn't have) managed to park just a few minutes' walk below the viewpoint above.
The Valley of the Moon is also well worth it. We were very glad to be under our own steam here: some parts were overrun with tour groups, especially the Salt Cavern, which wasn't the best place to get stuck behind 20 people. There's a lot to see there, including some old disused salt mines.
Here's a map: we flew in to Calama; the lakes are south of Socaire just by the marker that says "23"; and that's Argentina over on the right and Bolivia up north.
San Pedro itself is a bit of a strange town. There's a small vegetable market where we discovered rocoto peppers and wonderful local garlic, but we couldn't find anywhere else to buy supplies except for a very strange supermarket with no fresh food at all. Maybe there are more shops on the other side of town, or everybody who wants fresh bread either drives 100km to Calama to get it or bakes their own.
The Museo del Metorito is a few minutes' walk past the supermarket on the north side of town, and has an amazing selection of meteorites in a geodesic dome. The Atacama desert is apparently a very good place for meteorite hunters, as there's neither vegetation to hide them nor water to rust or dissolve anything. The English translations are sometimes a bit quirky: one rather beautiful pallasite was described as resembling a tutti-frutti. The other museum in town is the collection of Gustavo Le Paige, a Jesuit priest who collected pre-Columbian artefacts from the Atacama region. There was apparently some controversy about the presence of mummies: these are no longer on display. There is an interesting collection of pottery, some fabrics, and a remarkable collections of tools for preparing hallucinogenic snuff.
The big thing we failed to do was going for a star-watching expedition. These are advertised all over town, but shut down during the full moon because of the light pollution. The first couple of days we stayed there had beautifully clear skies and not too much moon, but we didn't book until later in the week, when it was too late to get a slot. I suspect that the operators had decided to stop a few days early to take a bit more time off before Christmas. The Lonely Planet suggested that we could book on line for a tour around the La Silla observatory, and I was extremely excited when we got a last-minute confirmation. I was then very confused when Google Maps showed that La Silla is 1100 km south, closer to Santiago than San Pedro. Perhaps they meant the ALMA radio observatory?
The rest of the place seems to be aimed at tourists: there are hostels, restaurants, and tour operators, all selling variations on the same few packages. We had a very good meal at Baltinache one night (where we had the fancy pisco sours from two posts ago) and a pretty passable pizza on our first night somewhere on the main tourist drag. The most notable thing about that place was that they were playing Peruvian pan-pipe music when we arrived but then changed to playing 80s hits half way through the meal. We stayed longer than we probably should have waiting for La Isla Bonita, but only got Rick Astley.