If you are studying geology you have surely heard of an ocean ridge. Its concept is explained in a somewhat complex context. It belongs to theories of Earth formation such as Tectonic platesThese are the theories that underlie the origin of mid-ocean ridges.
And it is that an oceanic ridge is nothing more than an underwater mountain range formed by the displacement of tectonic plates. Do you want to know the origin, characteristics and types of ocean ridges that exist on our planet?
Characteristics and origin of an oceanic ridge
When several mid-ocean ridges form under the oceans, authentic mountain systems are formed under the sea. The largest underwater mountain ranges in the world span a distance of 60.000 kilometers. The ocean ridges are separated by the ocean basins.
Its origin is given by the movement of the tectonic plates that form the Earth crustThe sediments that accumulate in submarine mountain ranges are at least ten times thicker than those on the continent. This gives rise to the geosynclinal theory. This theory states that the continental crust grows thanks to progressive and massive accumulations originating from ancient geosynclines and folds. Over time, these have hardened and consolidated into the current plates.
The study of mid-ocean ridges It is essential to understand its influence on the Earth's relief.
Structure of the dorsal
The vast majority of these underwater mountain ranges can reach measure between 2000 and 3000 meters in height. They generally have a rugged terrain, with wide slopes and very pronounced ridges. When these ridges have a deep cleft it is called sinking valley or rift. In the rifts numerous shallow earthquakes and volcanic eruptions in which large quantities of basalt are released.
The basalts give shape to the entire seabed. On the sides of the ridge, the thickness of the volcanic crust and the thickness of the sediments are increasing. There are also underwater volcanoes, but they are scattered and lonely. You don't necessarily have to be in a rift.
The ridges of the ridges can be laterally displaced along more extensive sections that correspond to the fracture zones. When we meet a boundary between two plates, hot, molten lava rises to the surface. Once it arrives, it cools and solidifies while the oldest crust separates on both sides of the ridge.
This is always scrolling. Proof of this is that the movement of the ocean ridges has been measured at some points in the Atlantic. Displacements of up to two centimeters per year have been recorded. On the other hand, in the eastern Pacific, measurements of displacement and data of 14 cm per year have been obtained. This means that mid-ocean ridges are not moving everywhere at the same speed. The change in the submerged volume of the ridges is causing slight changes in sea level on a geological scale. When we refer to the geological scale, we speak of thousands of years.
Complexity of an ocean ridge
On the ridges of the ridges we can find hydrothermal cracks. A steam with a high mineral content comes out of it and makes it at a temperature of 350 degrees. When minerals are deposited, they do so by forming column-like structures whose fundamental content is metal sulfide compounds. These sulfides are capable of supporting less common animal colonies. These compounds are an important part in the functioning of marine ecosystems. Thanks to this, the composition of the water is more stable.
The new oceanic crust generated at the ridges with part of the upper mantle and the upper crust form the lithosphere. All the marine centers extend on the mid-ocean ridges. For this reason, many of the characteristics found in these places are unique.
They are the subject of many studies. To gain a deeper understanding of the composition and evolution of ridges, basaltic lavas are studied. lovage They are gradually buried by sediments deposited across the entire surface. In many cases, the heat flow is stronger within the ridges than in the rest of the world.
It is very common for earthquakes to occur along the ridges and, above all, in the transformation faultsThese faults connect the segments of the offset ridge. Earthquakes occurring in these areas are studied in depth to gain insight into the Earth's interior.
Dorsal dispersion
On the other hand, there is a strong relationship between the depths that an oceanic ridge has with its age. In general, it has been shown that the depth of the ocean is proportional to the square root of the age of the crust. This theory is based on the relationship between age and the thermal contraction of the oceanic crust.
Most of the cooling for the formation of the ocean ridges occurred about 80 million years ago. At that time, the depth of the ocean it was only 5 km. Currently, it is known more than 10.000 meters deep. Because this cooling is a function of age, slow-spreading ridges, such as the Mid-Atlantic Ridge, are narrower than more rapidly expanding ridges, such as the East Pacific Ridge.
The width of a ridge can be calculated based on the rate of dispersal. They typically expand by about 160 mm per year, which is negligible on a human scale. However, on a geological scale, it is noticeable. The slowest-moving ridges are those that they are dispersed as little as 50 mm per year and the fastest up to 160 mm.
Slower-spreading ridges have rifts, while faster-spreading ridges don't. Slow-spreading ridges have irregular topography on their flanks, while faster-spreading ridges have much smoother flanks.
As you can see, a mid-ocean ridge is more complex than it seems. Its dynamics are defined by the terrestrial activity which is in constant movement.
Very cool!