At which boundary is sea floor created?
divergent plate boundaries
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.
What are formed when one part of the seafloor is forced under another part?
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.
Which location does gravity play a role in moving tectonic plates?
Though largely tangential, plate motion has a vertical component downward from the ridge crest, where the plate is generated, to the deep-sea trench where the plate presumably plunges through the asthenosphere and mesosphere of the earth. Thus, gravity generates an active driving component in the direction of motion.
What is oceanic continental plate?
Ocean-Continent Convergence. When oceanic crust converges with continental crust, the denser oceanic plate plunges beneath the continental plate. The subducting plate causes melting in the mantle above the plate. The magma rises and erupts, creating volcanoes.
What happens to the seafloor when two plates move apart?
In locations where two plates move apart, at mid-ocean ridges, new seafloor is continually formed during seafloor spreading. Seafloor spreading helps explain continental drift in the theory of plate tectonics. When oceanic plates diverge, tensional stress causes fractures to occur in the lithosphere.
How does seafloor spreading help explain continental drift?
Seafloor spreading helps explain continental drift in the theory of plate tectonics. When oceanic plates diverge, tensional stress causes fractures to occur in the lithosphere.
How are seafloor spreading ridges related to subduction zones?
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. Plates that are not subducting are driven by gravity sliding off the elevated mid-ocean ridges a process called ridge push.
What happens when oceanic crust meets continental crust?
Because it is denser, when oceanic crust and continental crust meet, the oceanic crust slides below the continental crust. This collision of oceanic crust on one plate with the continental crust of a second plate can result in the formation of volcanoes (Fig. 7.23).
https://www.youtube.com/watch?v=wLEbuJ5nyNA