Explain the difference between oceanic elevations and oceanic ridges, including examples – Oceanic elevations: The gently sloping and rapidly expanding portions of mid-ocean ridges. – Oceanic Ridges: Conversely, steeper-dipping and slower-spreading portions of the mid-oceanic ridge.
Similarly, you may be wondering what an oceanic rise is?
oceanic rise. [‚ō·shē′an·ik ′rīz] (geology) A long, broad elevation of the sea floor.
The question then arises what is the difference between an elevation and a ridge.
Wiseman and Ovey (1953) present the term oceanic rise as a long and broad elevation of the deep-sea floor that rises gently and steadily, and is thought to have a ridge with steeper sides and a less regular topography than a Rise has .
What do oceanic ridges represent in this regard?
The oceanic ridge is a continuous chain of underwater mountains, parts of which are found in every ocean in the world. The ridge system forms when magma rising between diverging plates of the lithosphere cools and forms a new layer of crust.
How does an oceanic ridge form?
A mid-oceanic ridge or mid-oceanic ridge is a Underwater mountains formed by plate tectonics. This seafloor uplift occurs when convection currents rise in the mantle beneath the oceanic crust, creating magma where two tectonic plates meet at a divergent boundary.
What is a ridge?
A Crest or a ridge is a geographical feature consisting of a chain of mountains or hills forming a continuous elevated ridge for some distance. The sides of the crest slope away from the narrow tip on either side. Ridges are also commonly referred to as hills or mountains, depending on their size.
What is meant by seafloor spreading?
Seafloor spreading is a process that occurs at mid-ocean ridges, where new oceanic Crust is formed by volcanic activity and then gradually moves away from the ridge.
What is the role of the mid-ocean ridge?
The main role of the mid-ocean ridge in the movement of plates is the fact that that it indicates that two plates are actually moving, either pulling or pushing each other. The mid-ocean ridge can also be considered as an underwater mountain range as two tectonic processes occur, ridge thrust and plate thrust.
Which ocean is the shallowest?
What is an example of a mid-ocean ridge?
Mid-ocean ridges form where two tectonic plates pull apart, also known as seafloor spreading. The Mid-Atlantic Ridge, which is expanding at one to two inches per year, and the East Pacific Ridge, which is expanding at two to six inches per year, are two examples of very long mid-ocean ridges.
Are subduction zones convergent or divergent?
Divergent boundaries are areas where plates diverge, forming either mid-ocean ridges or rift valleys. These are also referred to as constructive limits. Convergent boundaries are areas where plates move towards each other and collide. Subduction zones are marked by oceanic trenches.
What causes the shifts in the mid-ocean ridge system?
Every 50-500 km the mid-ocean ridge is shifted laterally to the right or left by transformation faults (to be found where two plates sliding sideways against each other). The ridge also has many smaller lateral offsets which, along with larger transform faults, divide the mid-ocean ridge into many segments.
Are grabens convergent or divergent?
No, ocean grabens do not occur at divergent plate boundaries on. They arise at converging boundaries.
What does abyssal plain mean?
An abyssal plain is an underwater plain at the bottom of the deep sea, typically at depths between 3,000 meters (9,800 ft) and 6,000 meters (20,000 feet). Deep-sea plains are formed when an originally uneven surface of oceanic crust is covered by fine-grained sediments, mainly clay and silt.
What is the main cause of convection in the Earth’s mantle?
Mantle convection is the very slow creeping motion of the of the Earth’s solid silicate mantle caused by convection currents that transport heat from the interior to the planet’s surface.
Where are the oceanic ridges located?
Oceanic ridges occur in every ocean basin forward and seem to gird the earth. The ridges rise from depths near 5 km (3 miles) to a substantially uniform depth of about 2.6 km (1.6 miles) and are roughly symmetrical in cross-section. They can be thousands of kilometers wide.
What is a rise in geology?
The continental rise is an underwater sediment found between the continental slope and the abyssal plain. This feature is found all over the world and represents the final stage of the boundary between the continents and the deepest part of the ocean.
Why do mid-ocean ridges rise so high from the sea floor?
Because hot rocks are in a more expanded state and then contract as they cool (as they spread away from the ridge), mid-ocean ridges rise high above the surrounding sea floor. The depth of the sea floor increases with distance from the mid-ocean ridges.
What are the two tectonic plates called?
Tectonic plates are parts of the Earth’s crust and uppermost mantle, collectively known as the are called lithosphere. The plates are about 100 km thick and are made up of two main types of material: oceanic crust (also called sima made of silicon and magnesium) and continental crust (sial made of silicon and aluminum).
How are trenches formed?
Trench trenches are formed by subduction, a geophysical process where two or more of Earth’s tectonic plates converge, pushing the older, denser plate beneath the lighter plate and deep into the mantle, forming the seafloor and outermost crust (the lithosphere) to bend and form a steep, V-shaped depression.
What lies beyond the continental slope?
About 8.5 percent of the ocean floor is covered by the continental slope-rise system. Beyond the shelf-slope breach, the continental crust thins rapidly, and the rise is partly on continental crust and partly on deep-sea oceanic crust.
How many tectonic plates are there?