How are ocean trenches and ridges formed?

How are ocean trenches and ridges formed?

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 causes ridges to form on the ocean floor?

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.

What ocean floor features is associated with trenches?

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 creates a trench?

Ocean trenches are a result of tectonic activity, which describes the movement of the Earth’s lithosphere. At many convergent plate boundaries, dense lithosphere melts or slides beneath less-dense lithosphere in a process called subduction, creating a trench.

How are seamounts formed?

At mid-ocean ridges, plates are spreading apart and magma rises to fill the gaps. Near subduction zones, plates collide, forcing ocean crust down toward Earth’s hot interior, where this crustal material melts, forming magma that rises buoyantly back to the surface and erupts to create volcanoes and seamounts.

Which type of boundaries movement causing the formation of oceanic ridges?

When two plates are moving away from each other, we call this a divergent plate boundary. Along these boundaries, magma rises from deep within the Earth and erupts to form new crust on the lithosphere. Most divergent plate boundaries are underwater and form submarine mountain ranges called oceanic spreading ridges.

What is ocean bottom relief?

Oceanic land-forms (submarine relief) There are mountains, basins, plateaus, ridges, canyons and trenches beneath the ocean water too. These relief features found on the ocean floor are called Submarine Relief. The ocean basins are broadly divided into four major subdivisions.

What makes exploring the ocean difficult?

“The intense pressures in the deep ocean make it an extremely difficult environment to explore.” Although you don’t notice it, the pressure of the air pushing down on your body at sea level is about 15 pounds per square inch. If you went up into space, above the Earth’s atmosphere, the pressure would decrease to zero.

What are ocean ridges quizlet?

an undersea mountain chain where new ocean floor is produced at a divergent plate boundary. sonar.