Why South America’s Geography is Broken

If you look at a map of South America, your eye is almost immediately drawn to the West. It's hard to miss. Running like a jagged spine down the entire length of the continent is the longest continental mountain range on Earth, the Andes. But this isn't just a mountain range. It's the Great Divider. So how does a single mountain range break the entire geography of South America? To answer that, let's take a look at just how physically dominating the Andes are. We often talk about mountains as static objects. Giant rocks that just sit there. But the Andes are different. It's an active, living engine that dictates the climate, the weather, and the very existence of nearly every ecosystem in South America. From the humid heat of the equator to the icy winds of Tierra del Fuego, the Andes are the single most dominant feature of the Southern Hemisphere. But to really understand why this mountain range breaks the geography of an entire continent, we have to first understand just how massive and how violent its creation really was. And trust me, the forces that built this wall are far from finished. Let's start with the sheer scale, because the numbers are honestly difficult to wrap your head around. The Andes stretch for nearly 8,000 kilometers, from Venezuela all the way down to Chile and Argentina. To put that in perspective, if you laid the Andes across the United States, they would stretch from New York City to Los Angeles and then back to New York City. And in terms of height, they're formidable. The average height is about 4,000 meters. The highest peak, Mount Ancangangua in Argentina, stands at a staggering 6,961 meters, making it the highest mountain outside of Asia. But here's where things get interesting. If you ask most people what the tallest mountain on Earth is, they'll say Mount Everest. And technically, above sea level, they're right. But because the Earth isn't a perfect sphere, it bulges at the equator due to its rotation, the peak of Mount Chimborazo in Ecuador is actually the point on Earth closest to the stars. That's right. If you measure from the center of the Earth, the Andes, not the Himalayas, hold the crown. So how did such an overwhelming geographic feature get created in the first place? The Andes were born from a collision of truly epic proportions. It's the result of the Nazca Plate and the Antarctic Plate subducting or sliding underneath the South American Plate, a process that's been going on for millions of years, forcing the land upward, crumpling the crust above. Because this is a subduction zone, the Andes are part of the Pacific Ring of Fire. This means they're volatile. We're talking about hundreds of active volcanoes and frequent, massive earthquakes. The very ground here is restless. In 1960, the Southern Andes were the site of the Great Chilean Earthquake, the most powerful earthquake ever recorded in human history. But the violence of the tectonic plates does more than just shake the ground. It captures the wind. And this is where the Andes stop being just a mountain range and start being a climate control machine. Because what happens when you put a 20,000 foot wall in the path of global wind currents? You don't just change the weather. You inadvertently create the largest rainforest on Earth. And just a few hundred miles away, a desert where it hasn't rained in centuries. This is the most critical function of the Andes. They act as a massive atmospheric barrier. In the northern and central parts of the continent, the prevailing trade winds blow from the east across the Atlantic Ocean, picking up massive amounts of moisture. As this warm, wet air travels across Brazil, it eventually hits the eastern slope of the Andes. The mountains then force the air upward. As the air rises, it cools and condenses, dropping almost all of its moisture on the eastern side. This phenomenon, known as orographic lift, is the engine that powers the Amazon rainforest. Without the Andes catching this water, the Amazon as we know it simply wouldn't exist. But nature is all about balance. If the Andes take all the water for the east, what's left for the west? Cross over the peaks to the western side, specifically around northern Chile and southern Peru, and you encounter the Atacama Desert. Because the Andes block the moisture from the east and the cold Humboldt current cools the air on the west, preventing evaporation, the Atacama is caught in a double whammy rain shadow. It's the driest non-polar place on Earth. There are weather stations in the Atacama that have never recorded rain. The landscape is so alien and barren that NASA uses it to test rovers bound for Mars. It's a stark red and brown contrast to the lush green hell of the Amazon just a short flight away. But since the Andes span the whole continent, if you head south, the dynamic flips. The winds change directions, blowing from the west. The Andes once again block the moisture, creating temperate rainforests in southern Chile, but casting a massive rain shadow over Argentina to the east. This creates the Patagonian Steppe, a vast, windswept, semi-arid plateau that feels more like the surface of a cold distant moon than the South America we usually picture. Before we move on, we have to recognize one last physical gift the Andes provide. They are the continent's water tower. The glaciers frozen in these peaks act as a savings account for fresh water. As they melt seasonally, they provide drinking water, hydroelectric power, and irrigation for tens of millions of people in cities like Lima, La Paz, and Santiago. Put simply, the major cities of South America wouldn't exist without the Andes acting as a crucial savings account of resources. And that logic applies to us too. To keep operating at a high level, you need a reliable nutritional resource to draw from, especially when life gets busy. So first, thank you to AG1 for sponsoring today's video. You guys know I travel a lot for these videos, and with the holidays coming up, my routine is about to get completely thrown off. When that happens, it's so easy for my nutrition to take a hit. That's why, for a long time now, the first thing I do every morning is drink AG1. It's just one scoop once a day, and it's the simplest way I've found to take ownership of my morning. The AG1 next-gen formula has more vitamins and minerals than ever before, and I'm personally a fan of the new tropical flavor, but they also have citrus and berry now too. It's my daily health drink with over 75 vitamins, minerals, and whole food-sourced ingredients. 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Now, AG1 is great for supporting your body in the modern world, but thousands of years ago, supporting the human body in the Andes required a completely different kind of engineering. The Andes are objectively one of the most difficult places on Earth for humans to survive. By all logic, civilization should have flourished But history rarely follows logic. Instead of avoiding the mountains, humans in South America flocked to them. The Andes didn't just host civilization, they became the cradle of it. While the rest of the world was developing in river valleys like the Nile or the Tigris, the original people of South America were building complex societies on the edges of cliffs. But how do you build an empire where you can barely breathe? The answer lies in some of the most ingenious engineering humanity has ever produced. When we think of the Andes, we almost immediately think of the Inca. But the Inca were actually the final chapter in a very long book. Long before the Inca rose to power, the Andes were home to the Norte Chico civilization in modern-day Peru. This civilization dates back to around 3500 BCE. Put that in perspective, they were building monumental architecture around the same time the Egyptians were figuring out how to stack stones for the pyramids. They thrived by trading between the seafood-rich coast and the resource-rich mountains, creating a vertical economy that defied the terrain. But as impressive as they were, they were just the warm-up act. Enter the Inca. In less than a century, they built the largest empire in the pre-Columbian Americas, stretching from Colombia to Chile. And they did it without the wheel, without iron, and without written language. Their secret weapon wasn't a weapon at all. It was agriculture. The Inca perfected the system of terrace farming. By carving steps into the mountainsides, they did three things. They created flatland where there was none before. They prevented the soil from washing away in landslides. And crucially, they created microclimates. But feeding people is one thing. Controlling them across 4,000 miles of jagged peaks is another. This is where the geography of the Andes forced the Inca to become the greatest road builders in history. They constructed the Qhapaq Nan, a road system spanning over 25,000 miles. And these weren't just dirt paths either. They were paved stone roads with suspension bridges made of grass woven so tightly they could hold armies. They engineered staircases up sheer cliffs and retaining walls that are still standing today, surviving earthquakes that level modern concrete buildings. This road system allowed the Inca to move armies and information at lightning speed. Runners known as chasqui operated in a relay system, carrying messages up and down the mountains. It's said that the Inca emperor in Cuzco could eat fresh fish caught in the Pacific Ocean that morning, delivered by foot over the Andes. But this incredible connectivity would eventually become their downfall because if a road can carry an emperor, it can also carry an invader. When the Spanish conquistadors arrived, led by Francisco Pizarro, the Andes presented a formidable barrier. The horses struggled in the altitude. The men froze in their armor. But the Spanish had a motivation that could move mountains. Silver. In 1545, in the high, desolate Bolivian Andes, the Spanish discovered Potosí. It was a mountain made of silver, literally. Potosí became the economic engine of the Spanish Empire and arguably the first city of modern capitalism. At its height, this high altitude mining camp was larger than London or Paris. But the human cost was catastrophic. The Spanish utilized the Mita system, a twisted version of mandatory Incan public service, to force indigenous people into the mines. The conditions were horrific. It's estimated that millions died in the mines of Potosí. The silver that flowed out of the Andes funded the Spanish Armada and changed the global economy, causing inflation as far away as China. So the Andes didn't just shape South America. They shaped the world economy at the time. As the colonial era ended and independence movements swept the continents in the 1800s, the Andes took on a new role, the divider. When you look at the borders of South America today, particularly in the South, you're looking at the Andes. The border between Chile and Argentina is essentially the ridgeline of the mountains. During the colonial period, these administrative lines were blurry because, well, no one wanted to climb the mountains to check exactly where the line was. But as countries formed, the Andes became the natural, albeit difficult, fortress. Take Chile, for example. It's the longest, thinnest country in the world. Why? Because the Andes press it up against the sea. The mountains effectively isolated Chile from the rest of the continent for centuries, allowing it to develop a distinct cultural and political identity, largely separated from its neighbors to the east. But this separation isn't just political. It creates a fundamental disconnect in how the continent functions. Basically, it's broken South America. The first way the Andes break the continent is by shattering its climate. While this might seem like a localized weather phenomenon, the geopolitical consequences are massive. On the east side, you have the Amazon Basin, the largest arable piece of land on the planet. But for centuries, it was an impenetrable green ocean. It's difficult to build roads through a rainforest that wants to eat your pavement. This forced Brazil to look toward the Atlantic coast, effectively turning its back on its western neighbors. On the west side, you have the arid coast. Peru and Chile are squeezed between the rock and the sea. Because the Andes block the Amazon's water, these countries rely heavily on glacial melt for survival. This creates a stark economic divide. The east is agricultural and biological. The west is mineral and maritime. They are two different economic engines that can't easily connect because there's a 20,000-foot speed bump in the middle, which leads us to the biggest problem the Andes create, the lack of easy transcontinental connections. In the United States, you can drive from New York to San Francisco on an interstate highway in a few days. You can ship goods by rail across the Rockies relatively easily because the passes are manageable. In South America, crossing the continent is a logistical nightmare. For most of its history, if you wanted to get goods from Lima to Buenos Aires, you didn't go overland. You put them on a ship and sailed all the way around the tip of the continent because that was actually easier than trying to get across the Andes. Even today, there are very few reliable paved crossings over the mountains. In winter, snow often shuts down the main pass between Chile and Argentina. This lack of infrastructure means that intra-regional trade in South America is incredibly low compared to Europe or Asia. It's often cheaper for Chile to trade with China than with Brazil. The Andes forced the continent to look outward rather than inward. This physical separation solidified the political fragmentation we see today. The Spanish empire tried to govern the continent as massive vice royalties, but they fell apart almost immediately after independence. Why? Because you can't govern people you can't reach. The Andes created isolated pockets of civilization. The people of Bogota developed a culture distinct from Caracas. Santiago developed differently from Buenos Aires. The mountains acted as incubators for nationalism, preventing a United States of South America from ever becoming a reality. Nowhere is this break more painful than in Bolivia. Bolivia is the heart of the continent, but it's a heart locked inside a cage of rock. After losing its coastline to Chile in the War of the Pacific, Bolivia became a landlocked country, stranded high in the Altiplano. Without direct access to the sea and surrounded by difficult terrain of the Andes, Bolivia has struggled to integrate with the global economy. It's a stark example of how geography can dictate a country's destiny. Today, modern engineering is trying to stitch the continent back together. There are massive projects underway like the Bioceanic Corridor, a planned road and rail network intended to connect the Brazilian Atlantic to the Chilean Pacific. The goal is to finally break the grip of the Andes and allow soy from Brazil to reach Asian markets through Pacific ports. But the mountains fight back. Building tunnels at 4,000 meters in an active earthquake zone is exorbitantly expensive and dangerous. And every time humans try to conquer the Andes, the Andes reminds us who is really in charge of South America. So, did the Andes break South America? Yes, they break the wind patterns to create deserts and rainforests. They break the connectivity that would allow for a unified economy. They broke the colonial territories into the countries we see today. But in breaking the geography, they also create something unique, a continent that is truly unlike anywhere else in the world. Speaking of incredible places, if you've been curious what I've been up to this past year, head over to my other channel, Geolax, where I'm recapping my first year of full-time travel. I hope you enjoyed learning all about the Andes Mountains. And be sure to check out this video about the Great Basin of North America for a similar video. Thanks for watching. See you next time.