Everything Everywhere Daily: History, Science, Geography & More - The Atacama Desert

Starting point is 00:00:00 Situated in the north of the nation of Chile lies one of the most extreme environments on planet Earth, the Atacama Desert. What makes the Atacama Desert so unique isn't its size or its temperature, but rather the amount of precipitation it gets, or the lack thereof. It's precipitation that defines what a desert is, and by that logic, the Atacama is the most deserty of all the deserts.

Starting point is 00:00:22 Learn more about the Atacama Desert, and what makes it so different and special on this episode of Everything Everywhere Daily? What if your perceptions about the past were wrong? ThruLine is a podcast that takes you back in time to uncover the parts of the story that may have gone unnoticed. It effectively turned day into night. And how it shaped the world now. Time travel with us every week on the Thurline podcast from NPR. The Atacama Desert is located in what is the northernmost 20% of Chile, with bits of it bleeding over into southern

Starting point is 00:01:14 Peru, southwestern Bolivia, and northwestern Argentina. It's sandwiched between the Andes Mountains and the Pacific Ocean, along 1,600 kilometers or 990 miles of land. Depending on how you define it, it has an area of approximately 105,000 square kilometers or 41,000 square miles. It would be a little bit bigger than Iceland. In terms of size, it would only be the 25th largest desert in the world, behind a bunch of better-known and lesser-known deserts. The average temperature in the Atacama is not nearly as hot as you might think. It has an average temperature of only 68 degrees Fahrenheit or 20 degrees Celsius. None of these statistics are particularly special, so why bother doing an episode on the Atacama Desert? It's because the Atacama Desert is one of the driest places on Earth.

Starting point is 00:02:01 Taken as a whole, the Atacama gets about 15 millimeters or 0.6 inches of rainfall per year. However, this is just the average. There are parts of the Atacama that have never in recorded history received any rain whatsoever. The town of Kalama had no recorded rainfall from the years 1570 to 1971. That is a drought that lasted 401 years. And here I should note that while there are places like Kalama that get no rainfall, technically speaking, there is one place on the world that is considered drier, and that would be the dry valleys of Antarctica.

Starting point is 00:02:38 In these valleys, which have no snow or ice, it's believed that there may not have been precipitation in over two. two million years. And the dry valleys of Antarctica will definitely be the subject of a future episode. Given that the Atacama runs along the coast near the Pacific Ocean, it seems that this is a rather odd spot for a desert, let alone one this dry. The reason why the Atacama is so dry has to do with geography. The Atacama is located between two mountain ranges, the Andes and the Chilean Coast mountain range. The higher Andes Mountains block the moist air which comes from the east. The Andes causes the moisture to precipitate on the eastern slope over in Argentina.

Starting point is 00:03:16 The Chilean Coast Mountains run alongside the coast and block moisture coming in from the Pacific Ocean. Moreover, the fact that the mountains run perpendicular to the prevailing winds means you wind up with more moisture being blocked than something like the Himalayas, which runs east-west along the direction of the winds. When a mountain range blocks moisture, it's called a rain shadow. The Atacama is located in a double rain shadow. Moreover, the current along the Pacific coast is the Humboldt current, which is carrying cold water up from Antarctica. The air along the coast is cooler than normal for that latitude, and thus carries less moisture.

Starting point is 00:03:53 And just as another point of reference, the Atacama is about 50 times drier than Death Valley, California. Given how geography has created the desert, the Atacama is also believed to be the oldest desert in the world, going back several million years. So, what are the implications of this extreme aridity? For starters, there is obviously very little life in the Atacama. The entire desert is almost devoid of vegetation, and as a result, there is pretty much no animal life as well. Even though it's not visible, there are parts of the desert that do have life. There are some species of desert flowers that have evolved to the dry conditions of the desert.

Starting point is 00:04:31 They have seeds that will lie dormant for years until they get moisture. About every five to seven years, these wildflowers will get just enough rain to bloom, and there will be a brief, intense explosion of color in the desert. There are over 200 identified species of wildflowers that exhibit this behavior. Other parts of the desert have thick fog that rolls in on a regular basis. One plant, known as a talancia, evolved to live off the moisture of the fog. However, dormant flowers and fog-thriving plants aren't the most interesting thing about life in the Atacama. The most interesting thing is that there are parts of the deep desert that are almost completely sterile. Almost everywhere you look on Earth, you can find microbes.

Starting point is 00:05:13 The types and number you find may vary, but you'll usually find something. In the deepest, driest parts of the Atacama, there's almost nothing. It turns out that the Atacama is one of the closest places on Earth to another place that's very dry, Mars. In 2003, NASA replicated the same experiments used on the Viking 1 and Viking 2 landers, to see if they could find any signs of life. They didn't find anything. However, subsequent research by NASA found that there is, in fact, life even in the deepest driest parts of the desert.

Starting point is 00:05:45 They dug down to a level of 20 centimeters and took samples, and were able to grow bacteria when they added water. The Atacama has subsequently been a testing ground for Martian and Lunar Rovers. A good approximation to Mars isn't the only thing that the Atacama has to offer the space sciences. It's also one of the best places on Earth for astronomical telescopes. What makes a good location for a large telescope is the number of nights each year that it can make observations. Because there is such little precipitation, there are a few clouds, and that means telescopes can observe for about 340 nights each year. And on top of that, it's far away from any cities

Starting point is 00:06:22 and their light pollution, and it is at an average elevation of about 7,000 to 8,500 feet above sea level. its home to a host of telescopes including the Atacama Large Millimetre slash Sub-Millimeter Array, the Atacama Pathfinder Experiment, the Atacama Cosmology Telescope, and the very large telescope. It will also be home to the extremely large telescope, which is currently under construction. When completed in 2027, its mirror will have a diameter of 39.3 meters or 130 feet, and it will be the largest single mirror telescope in the world. The land of the Atacama Desert has the largest deposits of sodium nitrate in the world. Sodium nitrate is known as Chilean Salt Peter, as it is similar to potassium nitrate, which is saltpetre.

Starting point is 00:07:10 There was a mining boom in the desert in the late 19th century to the early 1940s. Over 170 mining community sprang up in the desert to support the mining industry. However, the industry collapsed with the discovery of artificial nitrates, and today most of these towns are ghost towns. There are still some mines in the region that mine for other minerals such as gold, copper, and silver. The perceived wealth of the sodium nitrate deposits in the 19th century was the cause of what became known as the War of the Pacific. The War of the Pacific was fought between Chile and an alliance of Peru and Bolivia, over a five-year period between 1879 to 1884. Chile ended up winning the conflict, which resulted in Bolivia becoming a landlock country. Despite the lack of freshwater animals and arable land, there is evidence of ancient humans who actually lived in the Atacama.

Starting point is 00:07:59 The people who live there have been dubbed the Chinchoro. They eeked out an existence on the coast, and, based on the evidence of their waste that they left behind, it is estimated that 90% of their diet consisted of seafood. The Chinchoro people are best known for one thing in particular. Mummies. The Chinchoros were one of the only people found in world history who mummified everyone in society, regardless of social class. Moreover, the Chinchoro mummies are the oldest mummies ever found in the world.

Starting point is 00:08:27 The oldest Chinchoro mummy dates back to the year 7,000 BC, which is a full 4,000 years older than the oldest mummy found in Egypt. Many of the techniques used in the preparation of the dead were similar to what was done in Egypt. About 30% of the mummies found were preserved naturally, which is actually really easy to do in a location like the Atacama. The desert will naturally dehydrate everything. There are people who live in the Atacama Desert today, and they almost all live in cities that are situated on the coast. There is a population of over a million people spread out through the entire region.

Starting point is 00:09:01 The largest parts of the economy are mining and tourism, and there's some agriculture near the coast, which specializes in fruits and vegetables for export, as they tend to ripen there before the rest of the country. The Atacama Desert might not be the biggest desert in the world, but there's no other like it. Its age, its location, and its extreme aridity makes it one of the most unique places on planet Earth. Everything Everywhere Daily is an Airwave Media podcast. The executive producer is Darcy Adams. The associate producers are Thorne Thompson and Peter Bennett. Today's review comes from listener Sergeant Salt over at Apple Podcasts in the United States. They write, excellent podcast.

Starting point is 00:09:42 I've binged your show so hard during a lull in a usually busy schedule, and it's been a world win of interesting tidbits about a fascinating list. world. Many of the shows remind me of unforgettable topics I learned and forgot at some point over the years, and I was absolutely delighted to hear about them all over again. If you ever cover the Melbourne Olympic torch prank, I'll add a coveted six star. I know how. Thanks, Sergeant Salt. Learning is a lifetime pursuit. There are many things we may have come across in the past that we just need a refresher on to have it all come flooding back to us. As for the Melbourne Olympic torch prank, I've made a note of it. I don't know if it would be worthy of a full episode,

Starting point is 00:10:19 but I might have some ideas for where I could mention it. Remember, if you leave a review or send me a boostogram, you two can have it read on the show.

Everything Everywhere Daily: History, Science, Geography & More - The Atacama Desert

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