The Himalayan mountain range is one of the most important in the world due to its size, its environment, nature and for many more reasons. Several years ago there was a wide spread of information that revealed a surprising fact: the highest point on Earth is not actually the summit of Mount Everest, but the Chimborazo volcano located in the central Andes. This revelation arose from the realization that our planet is not perfectly spherical in shape, but rather has a slight flattening at the poles and a larger radius at the equator. This led many people to wonder how the Himalayas originated.
Therefore, in this article we are going to tell you how it originated from the Himalayas, its characteristics and much more.
How the Himalayas originated
The radius of the Earth at the latitude of Everest (27º 59' 17» N) is not equivalent to the radius at the latitude of Chimborazo (1º 28' 09» S). However, it is important to note that despite this discrepancy in distance from the center of the Earth, Everest still holds the distinction of being the tallest mountain on the planet. However, Knowing how the Himalayas originated remains a topic of great intrigue and importance.
The Himalayan system consists of multiple mountain ranges such as the Himalayas, the Karakoram and the lesser-known Hindu Kush. These three chains, stretching for approximately 3.000 km, traverse the southeastern part of the Eurasian continent, acting as a barrier between the Indian peninsula and the rest of the continent. Within this vast and intricate mountain system are the fourteen highest peaks in the world, commonly known as the "eight thousand", and all exceed 8.000 m in altitude.
To know how the Himalayas originated we must resort to the theory of plate tectonics. The ever-changing nature of the Earth's surface is no secret. Continents that are currently separated were once united, while others that are currently connected were once separated. However, it is important to note that when we refer to the movement of the continents, it is actually the tectonic plates that are in motion. These plates, which consist of the crust and the upper part of the mantle known as the lithosphere, float on top of a partially molten layer called the asthenosphere.
The continents are dragged along with these lithospheric plates, like ice cubes in a shaken soda, as they approach, move apart, collide, overlap, and drift apart. Likewise, tectonic plates experience the same movements, but in this case it is the internal forces of the Earth itself that stir up the metaphorical soda of our planet. Occasionally, lithospheric plates move apart, resulting in the creation of new ocean basins located between continents (known as divergent edges). Alternatively, the plates can be shifted laterally (transformed edges). However, there are cases where plates collide, causing the closure of the oceans and the formation of extensive mountain chains (convergent or destructive edges).
This is precisely what happened in the Himalayas, a momentous collision between India and Eurasia. It is worth noting that before this major collision, there were smaller collisions that also played an important role in shaping this mountain range.
Impact of clash between continents
When continents collide, they suffer different types of deformations that give rise to various structural elements. Ductile behavior leads to the formation of folds, while brittle behavior produces failures such as slip, reverse and normal faults, as well as thrusts. A thrust fault is essentially a low-angle reverse fault where the rising block passes over the sinking block.
Thrust faults are an effective mechanism for shortening horizontal distances, but they also cause the crust to thicken due to stacking. This thickening can promote the fusion of rocks at depth and the generation of magmas, which They often remain underground and cool to form anatectic granites rather than erupting as volcanoes.
The Himalayas provide an excellent example of these processes, where evidence suggests not just one, but three separate collisions, with continental blocks separated by remnants of ancient oceans known as suture zones.
Geological evidence about how the Himalayas originated
Geological evidence confirms that the formation of the Himalayas is a long and complex process involving the convergence and collision of multiple continental blocks. This intricate story began during the Late Jurassic period, approximately 140 million years ago, when the volcanic island arc of northern Tibet collided with the southern margin of Eurasia, merging with it.
Later, in the Early Cretaceous period, about 100 million years ago, a second volcanic arc known as Southern Tibet also collided and merged with the continent. The third and last collision of continents took place during the Eocene epoch, about 40 million years ago when India arrived and collided with Eurasia. However, unlike previous volcanic arcs that had merged with the continent and ceased movement, India continued its advance northward, causing the crust to fold and giving rise to a colossal orogenic collision today known as the Himalayas.
While cortical thickening is undoubtedly an important factor contributing to the altitude of this mountain range, it is essential to recognize the role of isostasy, another crucial geological phenomenon that cannot be overlooked in discussions about mountains. In a future entry we will delve into the topic of isostasy and its meaning.
The current situation of the Himalayas
The current history of the Himalayas is complex and far from over. Currently, India continues its northward advance, resulting in a gradual rise of the majestic mountain range. This perpetual motion has led geologists to classify the Himalayan region as tectonically active, meaning it experiences multitudes of earthquakes each year. While most of these tremors are minor, occasionally a significant one occurs. Such was the case in 2015, when a powerful earthquake struck Nepal on April 25, registering a magnitude of 7,8. Before that, In January 1934, another magnitude 8 earthquake shook the region. These events serve as a reminder that earthquakes are not as rare as we may sometimes perceive, underscoring the dynamic nature of our living planet.
I hope that with this information you can learn more about how the Himalayas originated and what some of their characteristics are.