Increased heating causes increased expansion which translates to further uplift. That magma can melt parts of the continental crust which produces additional magma. The initial stage of continental rifting commonly includes broad uplift of the surface as mantle-derived magma ascends into crust. ![]() If continental rifting progresses it can lead to seafloor spreading and the formation of a new ocean basin. When you have divergence within a continent it is called continental rifting and it creates a continental rift. What is Continental Rifting? Most divergent boundaries are beneath oceans but a divergent boundary can form within a continent. The elevation of the seafloor decreases away from the ridge because the rock cools and contracts. Mid-ocean ridges are elevated above the surrounding seafloor because they consist of hotter, less dense materials and the underlying asthenosphere is thinner and bulging right beneath the ridges. These eruptions create new ocean crust that is incorporated into the oceanic plates as they move apart. Much of the magma solidifies at depth but some erupts on the seafloor forming submarine lava flows. The magma rises along narrow conduit, accumulates in magma chambers beneath the rift and eventually becomes part of the oceanic lithosphere. As the plates pull apart, the load on the asthenosphere decreases which decreases the pressure in the asthenosphere and leads to decompression melting. ![]() As the plates move apart, an opening is created which allows the asthenosphere to rise toward the surface to fill that space. That movement causes faulting which results in frequent small to moderate-sized earthquakes. The rift forms because large blocks of crust slip down as spreading occurs. A narrow trough, or rift runs along the axis of most mid-ocean ridges. Mid-ocean ridges are also called spreading centers because of the way the plates spread apart. This is where new oceanic lithosphere forms. When a divergent boundary occurs between two oceanic plates a mid-ocean ridge. Its gotten so big that now the ocean stretches as far from Europe, Africa to America.What is a Divergent Boundary? A divergent boundary is a type of plate boundary where two plates move apart or diverge relative to one another. This process has been going on for millions of years and has cause the ocean to grow. The Mid-Atlantic ridge system moves apart an average 2.5 centimeters a year. ![]() This segment of the global mid ocean ridge system that encircles the earth. It stretches from the Arctic Ocean to the southern tip of Africa. Its a mountain range under water that was created over 200 million years ago. An example of Oceanic Diversion is the Mid-Atlantic Ridge.Tectonics comes from the Greek word meaning "builder." The movement of the plates toward or away from each other either directly or indirectly creates the major geologic features at Earth's surface. Plate tectonics is the geologic theory that Earth's crust is made up of rigid plates that "float" on the surface of the planet.oceanic - oceanic divergent is were an oceanic plate is subducted under another plate which causes a deep oceanic trench, and underwater volcanos form.Divergent boundaries - where new crust is generated as the plates pull away from each other.
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