Mid-ocean ridges mark these sites where the ocean floor is spreading
apart. As the ridges continue to widen, a gap called a
forms. Here molten material rises to build new crust.
When molten material rises from the asthenosphere,
cold ocean water cools the rock until it becomes solid. As the plates
move apart, new cracks open in the solid rock. More molten material
rises and hardens. The growing ridge stands high above the sea floor.
The world's longest ridge, the Mid-Atlantic Ridge, runs the length
of the Atlantic Ocean. Here the North and South American plates are
moving away from the Eurasian and African plates. The ridge extends
nearly 11,000 kilometers (6214 mi) from Iceland to near Antarctica.
The rift valley is 24 kilometers (15 mi) wide and 9 kilometers (6 mi)
deep-about 7 kilometers (4 mi) deeper than the Grand Canyon!
Mid-ocean ridges are divergent plate boundaries where new oceanic crust forms as tectonic plates move apart. At these boundaries, magma rises from the mantle, cooling and solidifying to create new crust.
In sea-floor spreading, the old oceanic crust is pushed away from the mid-ocean ridge as new molten material rises from the mantle. As the new material solidifies, it forms new oceanic crust, leading to the spreading of the seafloor and the continuous creation of new crust. The older oceanic crust eventually gets subducted back into the mantle at tectonic plate boundaries.
When new crust is made, like at a spreading center, old crust must be destroyed, like at a subduction zone, where it is brought back into the inner earth and melted and recycled through.
In seafloor spreading, the old crust moves away from the mid-ocean ridge as new crust forms through volcanic activity. This movement is driven by the process of mantle convection, where hotter and less dense material rises at the ridge, pushing the tectonic plates apart. As new crust forms at the ridge, it gradually moves away from the ridge as more magma is added, creating a conveyor belt-like system of crustal movement.
near ocean trenches.
Just as new oceanic crust forms at mid-ocean ridges, old oceanic crust is destroyed at subduction zones.
Mid-ocean ridges are divergent plate boundaries where new oceanic crust forms as tectonic plates move apart. At these boundaries, magma rises from the mantle, cooling and solidifying to create new crust.
In sea-floor spreading, the old oceanic crust is pushed away from the mid-ocean ridge as new molten material rises from the mantle. As the new material solidifies, it forms new oceanic crust, leading to the spreading of the seafloor and the continuous creation of new crust. The older oceanic crust eventually gets subducted back into the mantle at tectonic plate boundaries.
When new crust is made, like at a spreading center, old crust must be destroyed, like at a subduction zone, where it is brought back into the inner earth and melted and recycled through.
As new oceanic crust forms at mid-ocean ridges, old oceanic crust is destroyed at subduction zones.
The crust is new.
The older oceanic crust moves away from the spreading center and is eventualy subducted back into the mantle.
The older oceanic crust moves away from the spreading center and is eventualy subducted back into the mantle.
The older oceanic crust moves away from the spreading center and is eventualy subducted back into the mantle.
In seafloor spreading, the old crust moves away from the mid-ocean ridge as new crust forms through volcanic activity. This movement is driven by the process of mantle convection, where hotter and less dense material rises at the ridge, pushing the tectonic plates apart. As new crust forms at the ridge, it gradually moves away from the ridge as more magma is added, creating a conveyor belt-like system of crustal movement.
The diagram displays divergent plate boundaries where tectonic plates move apart, allowing molten material from beneath the Earth's crust to rise to the surface. As the molten material cools, it solidifies and forms new crust. This process is known as seafloor spreading.
cause its cooler