What Happens To The Seafloor At Trenches?

What is the theory of seafloor spreading?

Seafloor spreading, theory that oceanic crust forms along submarine mountain zones, known collectively as the mid-ocean ridge system, and spreads out laterally away from them.


Is the ocean floor being made or destroyed at the deep sea trench?

The Process of Subduction They move the ocean floor as if it were on a giant conveyor belt. New oceanic crust is hot. But as it moves away from the mid-ocean ridge, it cools and becomes more dense. … Figure 19Subduction Oceanic crust created along the mid-ocean ridge is destroyed at a deep-ocean trench.

Is crust formed or recycled at the trenches?

As old oceanic crust was consumed in the trenches, new magma rose and erupted along the spreading ridges to form new crust. In effect, the ocean basins were perpetually being “recycled,” with the creation of new crust and the destruction of old oceanic lithosphere occurring simultaneously.

Why are most oceanic trenches in the Pacific?

The Pacific is therefore expected to be narrower and the Atlantic wider. … 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. 3.

Where are deep sea trenches found?

Deep-sea trenches generally lie seaward of and parallel to adjacent island arcs or mountain ranges of the continental margins. They are closely associated with and found in subduction zones—that is, locations where a lithospheric plate bearing oceanic crust slides down into the upper mantle under the force of gravity.

What is the deepest trench in the world?

In the Pacific Ocean, somewhere between Guam and the Philippines, lies the Marianas Trench, also known as the Mariana Trench. At 35,814 feet below sea level, its bottom is called the Challenger Deep — the deepest point known on Earth.

How thick is Earth’s crust?

The crust thickness averages about 18 miles (30 kilometers) under the continents, but is only about 3 miles (5 kilometers) under the oceans. It is light and brittle and can break. In fact it’s fractured into more than a dozen major plates and several minor ones.

What does Trench mean?

A trench is a deep and narrow hole, or ditch, in the ground, like the kind soldiers on frontlines might dig to give themselves shelter from the enemy. … The verb trench means to dig or to cut into, but you will most often hear the word as a noun, particularly relating to soldiers.

What causes trenches in the ocean floor?

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.

Which part of the ocean floor is the flattest?

abyssal plainsAnswer and Explanation: The flattest portion of the ocean is known as the abyssal plains.

What lives in the deep ocean trenches?

The three most common organisms at the bottom of the Mariana Trench are xenophyophores, amphipods and small sea cucumbers (holothurians), Gallo said. The single-celled xenophyophores resemble giant amoebas, and they eat by surrounding and absorbing their food.

Where is the youngest material in the seafloor found?

The youngest crust of the ocean floor can be found near the seafloor spreading centers or mid-ocean ridges. As the plates split apart, magma rises from below the Earth’s surface to fill in the empty void.

Is the Mariana Trench still forming?

The Mariana Trench was formed through a process called subduction. Earth’s crust is made up of comparably thin plates that “float” on the molten rock of the planet’s mantle. … Today, the majority of the Mariana Trench is a U.S. protected zone as part of the Marianas Trench Marine National Monument, established in 2009.

Why is the ocean floor so difficult?

Why is much of the ocean floor so difficult to see? … In the movie, Tim says that ocean currents deposit sediment on the ocean floor.

What are 4 types of ocean floor?

Lesson SummaryStudying the ocean floor is difficult because the environment is so hostile. … Features of the ocean floor include the continental shelf and slope, abyssal plain, trenches, seamounts, and the mid-ocean ridge.The ocean floor is rich in resources.