Mid-ocean ridges are giant underwater mountain ranges formed by the constant movement of plates and the heat and magma that erupt from the Earth’s core. This phenomenon has existed since the Earth’s evolution, both in the form of land and water. They form as a result of convection lifting the seafloor, causing the oceanic lithosphere, crust, and upper mantle to spread across discrete plate boundaries.
How do mid-ocean ridges spread?
Mid-ocean ridges are a unique feature of ocean basins. Around the world, mid-ocean ridges are interconnected to form a single world mid-ocean ridge system that is part of every ocean. Mid-ocean ridges spread through two processes: ridge thrust and plate pull. The more dominant process has not yet been discovered.
Ridge thrust is when the weight of a ridge pushes a plate away from the ridge into a subduction zone, creating a plate pull in the subduction zone. Finally, the weight of the plate is pulled under the plate above, pulling the remaining plate with it.
Mid-ocean ridges
Mid-ocean ridges are amazing and come in a variety of shapes and forms. These include volcanic hills, rift or transform fault zones, fissures, rift valleys, fractures, etc. It stretches for 65,000 kilometers or 40,000 miles, making it the longest mountain range on Earth. These hills are flanked by abyssal plains and sometimes accompanied by natural faults, which form ocean nuclei.
Causes 75% of volcanic activity on Earth.
Most of Earth’s volcanic activity, including volcano formation and eruption, occurs at mid-ocean ridges, where new ocean crust is formed from lava and sediments. These mid-ocean ridges may have caused many submarine and surface hazards over the years, such as tsunamis and earthquakes, but for now, all seems well.
Basalt is the most common rock and erupts in scattered centers along the mid-ocean ridges. Scientists study mid-ocean ridges to understand how the Earth works, topography, biology, physics, and chemistry.
Hydrothermal vents near mid-ocean ridges
Seawater constantly flows through the cracks or ridges of the mid-ocean ridges through hydrothermal circulation. When the cold, downward-flowing ocean water comes in contact with the newly formed hot crust beneath the surface, various minerals and metals are transferred into the water. Hot, mineral-rich fluids flow out of the cracks, forming hydrothermal vents.
When hot water comes in contact with icy water on the ocean floor, minerals precipitate out of solution, forming black clouds or chimneys that erupt from previously frozen mineral chimneys. Huge amounts of minerals are released from these vents, making them some of the richest mineral deposits in the world. The mineral-rich hot water also supports deep-sea marine life that survives by absorbing hydrogen sulfide from the water.
Distant Phenomenon
Erupting lava and magma to form mid-ocean ridges is a divergent phenomenon. Instead of converging together, the newly formed underwater terrain diverges and takes new paths, separating the ocean floor. There are two types of mid-ocean ridges: slow-spreading ridges, fast-spreading ridges, and axial ridges.
These plates that create mid-ocean ridges also divide the Earth’s land masses into different continents. The constant movement and heating under the Earth’s crust are also responsible for the formation of landmasses. The extensive study of the complex process of the formation of mid-ocean ridges shows that the ongoing process may further separate the existing continents and countries.
This is a slow process, and since the Earth’s core never cools down, it cannot be stopped. Notable examples of the formation of mid-ocean ridges include Africa, the Red Sea, and the United States. Due to the excessive heat, the mid-ocean ridges begin to move, and new ridges begin to form.
Mid-Atlantic Ridge and East Pacific Ridge
These are two of the most well-analyzed ocean chains on Earth. The 16,000 km long Mid-Atlantic Ridge was formed when North America separated from Europe about 80 million years ago. It was discovered in the 19th century when the first transatlantic cable was laid. The Mid-Atlantic Ridge runs through the center of the Atlantic Ocean and is a slowly spreading ridge that grows at a rate of 2 to 5 cm or 10 to 150 mm per year.
The East Pacific Ridge is located on the Pacific Ocean floor. It spreads very quickly, at a rate of 6 to 16 cm per year. Because this process is so rapid, no valleys are formed in the Pacific Ocean. It has only one volcanic peak, which is smaller than the Atlantic Rift Valley. Most of this mountain range is located more than 3,200 km (2,000 mi) off the coast of South America and rises 1,800 to 2,700 m (6,500 to 8,000 ft) above the seafloor.
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Southwest Indian Range and Jakayel Range
In addition to slow and fast-growing hills, some hills spread very slowly, such as the Southwest Indian Range and the Jakayel Range. The first strait bisects the ocean between Africa and Antarctica, while the other connects the Mid-Indian Ridge to southeastern India near Madagascar. The hills are spreading at a moderate rate.
The Jakayel Range, on the other hand, has the lowest spreading rate of all the ridges, at 1.1 cm/A-1. The West Iceland Volcanic Area, part of the Dying Ridge, has a spreading rate of <0. Iceland was formed from a hotspot beneath the center of spreading.
The flanks of the slow-growing hills have rugged terrain, while the flanks of the faster-growing hills have flatter terrain.
Conclusion
Earth is the only planet that we know of that has life. Through thousands of years of evolution, from the time when dinosaurs and other creatures roamed the Earth to the present day when humans began to find ways to develop and improve the quality of life, the Earth has been benefiting from its resources.
Just as evolution changed the course of Earth’s terrain and led to the extinction of the dinosaurs, evolution may change Earth’s geography and topography in the coming years. The mid-ocean ridges are just one example of Earth’s evolution.
