What do plate tectonics and ocean trenches have in common?
In particular, ocean trenches are a feature of convergent plate boundaries, where two or more tectonic plates meet. At many convergent plate boundaries, dense lithosphere melts or slides beneath less-dense lithosphere in a process called subduction, creating a trench.
How is plate tectonics related to oceans?
Throughout Earth’s history, the global ocean has been modified by plate tectonics. Often, large continents assembled from smaller ones produced more expansive oceans between them.
How are mid-ocean ridges and trenches related?
The oceanic lithosphere is formed at an oceanic ridge, while the lithosphere is subducted back into the asthenosphere at ocean trenches. Two processes, ridge-push and slab pull, are thought to be responsible for spreading at mid-ocean ridges.
How is plate tectonics responsible for the formation of Earth’s deepest ocean trench?
Trenches are formed by subduction, a geophysical process in which two or more of Earth’s tectonic plates converge and the older, denser plate is pushed beneath the lighter plate and deep into the mantle, causing the seafloor and outermost crust (the lithosphere) to bend and form a steep, V-shaped depression.
What happens to oceanic crust at a deep ocean trench?
What happens to oceanic crust at a deep-ocean trench? At a deep-ocean trench, the oceanic crust bends downward. In a process taking tens of millions of years, part of the ocean floor sinks back into the mantle at deep-ocean trenches.
How are mid ocean ridges and trenches similar and different?
Mid-ocean ridges are areas of rifting where two tectonic plates are diverging from one another. … Deep-ocean trenches are formed at convergent plate boundaries where the more dense plate (usually the oceanic) subducts under the less dense (usually continental).
How are mid ocean ridges and trenches different?
Explanation: Mid ocean ridge are where new crustal material is forced to the surface. The new crustal material is pushed apart forming two different plates moving in two different directions. An ocean trench is where old crustal material is pushed under another plate where it is melted and turned into magma.
How do mid ocean ridges and trenches form during convection currents?
They move because of something called convection currents. Convection currents push these plates together and apart. … When two oceanic plates are pushed away from each other, magma rises to the surface between the plates and creates a ridge.
How do trenches and ridges form?
Trench: very deep, elongated cavity bordering a continent or an island arc; it forms when one tectonic plate slides beneath another. Ridge: underwater mountain range that criss-crosses the oceans and is formed by rising magma in a zone where two plates are moving apart.
How does plate movement cause ridges?
When subduction occurs, a chain of volcanoes often develops near the convergent plate boundary. … A divergent plate boundary often forms a mountain chain known as a ridge. This feature forms as magma escapes into the space between the spreading tectonic plates.
What’s the difference between Rift and trench?
As nouns the difference between trench and rift
is that trench is a long, narrow ditch or hole dug in the ground while rift is a chasm or fissure.
Why are most oceanic trenches found in the Pacific Ocean?
Why are most oceanic trenches found in the Pacific Ocean? The Pacific Ocean is shrinking and plates are descending below surrounding plates along its edges, hence the creation of trenches.
How are ocean ridges formed?
Mid-ocean ridges occur along divergent plate boundaries, where new ocean floor is created as the Earth’s tectonic plates spread apart. As the plates separate, molten rock rises to the seafloor, producing enormous volcanic eruptions of basalt.
How deep are deep sea trenches?
deep-sea trench, also called oceanic trench, any long, narrow, steep-sided depression in the ocean bottom in which occur the maximum oceanic depths, approximately 7,300 to more than 11,000 metres (24,000 to 36,000 feet). They typically form in locations where one tectonic plate subducts under another.
What Marine province contains deep ocean trenches that form along convergent plate boundaries as a result of subduction?
Examples of ocean-ocean convergent zones are subduction of the Pacific Plate south of Alaska (creating the Aleutian Islands) and under the Philippine Plate, where it creates the Marianas Trench, the deepest part of the ocean.
What happens when two oceanic plates collide?
A subduction zone is also generated when two oceanic plates collide — the older plate is forced under the younger one — and it leads to the formation of chains of volcanic islands known as island arcs. … Earthquakes generated in a subduction zone can also give rise to tsunamis.
Why does the Atlantic Ocean have few ocean trenches compared to the Pacific Ocean?
Why does the Atlantic Ocean have few ocean trenches compared to the Pacific Ocean? The Pacific Ocean has many convergent boundaries. … These are all subduction zones resulting in trenches of varying depths. The Atlantic Ocean has few convergent boundaries and, as a result, few trenches.
What type of plates collide in oceanic oceanic convergence?
An oceanic convergent plate boundary forms where two plates collide. In these collisions, one plate sinks beneath the other. A subduction zone forms along the boundary where the denser plate sinks into the mantle and is heated, causing plumes of molten magma to rise upward through the top plate.