What is it called when the ocean floor sinks back into the mantle?

What is it called when the ocean floor sinks back into the mantle?

9. The process by which the ocean floor sinks into the mantle is called Subduction ..

What are 2 pieces of evidence that support seafloor spreading?

Look at Figure 19 to see the process of sea-floor spreading. Several types of evidence from the oceans supported Hess’s theory of sea-floor spreading-evidence from molten material, magnetic stripes, and drilling samples. This evidence also led sci- entists to look again at Wegener’s theory of continental drift.

Is it true that a deep ocean trench is an underwater mountain?

A deep-ocean trench is an underwater MOUNTAIN. Molten material erupts INSIDE the central valley of mid-ocean ridges. The farther from a mid-ocean ridge a rock sample is taken, the YOUNGER the rock is. Sea-floor spreading occurs at MID-OCEAN RIDGES.

What is the root cause of seafloor spreading?

Seafloor spreading occurs at divergent plate boundaries. As tectonic plates slowly move away from each other, heat from the mantle’s convection currents makes the crust more plastic and less dense. The less-dense material rises, often forming a mountain or elevated area of the seafloor. Eventually, the crust cracks.

What causes the seafloor to move?

1 Answer. The seafloor changes because of the earth plates moving causing magma to spew in the water. The magma is then pushed outward causing the seafloor to move and change.

What force is causing the seafloor spreading?

When oceanic plates diverge, tensional stress causes fractures to occur in the lithosphere. The motivating force for seafloor spreading ridges is tectonic plate slab pull at subduction zones, rather than magma pressure, although there is typically significant magma activity at spreading ridges.

What is it called when new crust is created?

Understanding plate motions [This Dynamic Earth, USGS] Divergent boundaries — where new crust is generated as the plates pull away from each other. Convergent boundaries — where crust is destroyed as one plate dives under another.

What part of the ocean is 5200 m?

Tasman Basin

Which is the largest ocean in the world?

Pacific Ocean

Which is the 3 largest ocean in the world?

Indian Ocean