Mountains form over millions of years. They are found throughout the world. They come in many different shapes, types, and sizes. A mountain is any landmass higher and steeper than a hill. Mountains are crucial in shaping the Earth’s landscape, influencing climate patterns, providing habitats for diverse ecosystems, and serving as essential water catchments.
They result from dynamic geological processes that continue to shape and reshape the Earth’s surface over geologic timescales. Many geographers agree that mountains are at least two thousand feet high and have a slope greater than two degrees. Does Earth need the mountains? Let’s discover the answer!
Why Do We Have Mountains? (Mountains Creation)
Mountains are majestic doors that are essential components of geography. Most of the Earth’s surface is water, and 90 percent is salted, not drinkable. Only three percent of the world’s water is freshwater. About 60 to 80 percent of this freshwater comes from the mountains. That’s why they are nature’s water.
Here are the main reasons why mountains exist:
Plate Tectonics: The Earth’s lithosphere comprises several large and smaller plates that float on the semi-fluid asthenosphere beneath them. The movement and interaction of these plates give rise to various geological features, including mountains. There are three main types of plate boundaries where mountains are typically formed:
Convergent Boundaries: When two plates collide, it can result in the formation of mountain ranges. This occurs when one plate is forced beneath the other in a process known as subduction, causing compression, folding, and uplift of the Earth’s crust. Examples: The Himalayas formed by the collision of the Indian and Eurasian plates.
Divergent Boundaries: At divergent plate boundaries, where plates move apart, new crust is formed through volcanic activity. This can lead to the creation of underwater mountain ranges, such as the Mid-Atlantic Ridge or the East African Rift.
Transform Boundaries: Significant faulting and folding can occur along transform plate boundaries, where plates slide past each other horizontally. While these boundaries don’t typically create large mountain ranges, they can result in smaller mountain features due to intense pressure and deformation.
Uplift and Erosion: Besides tectonic processes, mountains can be shaped by the forces of uplift and erosion. Uplift refers to the vertical movement of the Earth’s crust, which can occur due to tectonic forces or the isostatic rebound after removing heavy overlying loads (e.g., glaciers). Erosion, caused by weathering, water, wind, and ice, gradually wears away the surface, sculpting mountains into characteristic shapes over millions of years.
Volcanic Activity: Volcanoes, associated with mountains, form when molten rock (magma) rises to the Earth’s surface through volcanic vents or fissures. Repeated eruptions and the accumulation of solidified lava and volcanic materials contribute to the growth of volcanic mountains, such as Mount Fuji in Japan or Mount St. Helens in the United States.
Always mountains absorb a huge amount of rainwater, preventing erosion, landslides, and rockfalls. Mountains are like safety rules for the people living there as they reduce rapidly moving winds.
It is why mountainous countries do not suffer from hurricanes or tornadoes. Mountains capture the clouds, making clouds tend to go high in the sky and cool down. Griselle mountains provide a huge amount of minerals that are vital for us. They are a good source of food and medicine. Around half the world’s population depends on mountains for water, food, and energy.
- Without mountains, the Earth will be a desert, and we can not survive properly. The Earth has plenty of mountains to maintain natural balance and keep rigidity.
Mountain belts extend for hundreds or even thousands of kilometers, and their structures penetrate the Earth. So their size and age make their formation challenging to understand. French geologist Jacques Malavika built sand models that mimic mountain belts and allowed scientists to study this complex process. It represents natural phenomena that happen over many tens of millions of years.
Sand is an excellent material for simulating rock formation. The sediments and the continental crust have different mechanical properties. Geologists mix the sand grains with a finer powder, increasing the sand’s deformation resistance. Thus, they have heterogeneous materials consisting of more resistant and less resistant layers.
Mountain belts occur when continents collide. The ocean basin closes as one plate subducts or dives beneath the other. The continental crust, lighter than the oceanic crust, cannot be subducted. Instead, the crust thickens and is forced up as the continents collide.
This process happens with the mountains. That’s why the Earth has many mountains. One crucial factor not accounted for in this model is erosion. Erosion exposes the deformed rocks once deeply buried in the mountain belt. The ocean basin has been trapped between the two continents marking their original boundary. These two are in mountain belts.
Different types of mountains on Earth
There are many types of mountains, and they’re classified by how they form. Volcanic and Dome mountains form from the molten rock or magma beneath the Earth’s crust.
Volcanic mountains occur when erupting. The magma cools and hardens, forming a cone shape down. Many volcanic mountains occur at convergent boundaries. Most of the Earth’s active volcanoes are concentrated around the edge of the Pacific Ocean. This area is known as the Ring of Fire. Mount Griggs in Alaska is an example. It is located on the northern rim of the Pacific plate. Japan’s Mount Fuji is a famous volcanic mountain, while the Adirondacks and the eastern US are well-known dome mountains.
Fold mountains form when the plates that make up the Earth’s crust collide or pass over the top of one another, causing the crust to unfold. The Rocky Mountains in the North American West and Europe’s Alps are folded mountains.
Block mountains create when pressure on giant cracks in the Earth’s crust or faults causes rock slabs to tilt upward and sometimes stacked on top of one another. When tension causes the lithosphere to break into normal faults, the lithosphere drops down. The pieces left standing form fault-block mountains, the Teton Mountains, or an example in the Sierra Nevada.
America’s Sierra Nevada Mountains are the Black Mountains, the highest mountain on Earth, and Mt. Everest in the Himalayan Mountains. Its peak reached twenty-nine thousand twenty-nine feet above sea level and is still growing if you measure up mountains might by its area. Hawaii’s volcanic Mauna Loa is the world’s largest at about seventy-five miles across.
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