Coastal and Oceanic Landform (33. Mid Oceanic ridge )

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  • A mid-ocean ridge called as an underwater mountain system.
  • It consists of various mountain ranges.
  • The uplifted seafloor results from convection currents.
  • which rise in the mantle as magma at a linear weakness in the oceanic crust.

Including a black smoker
Including a black smoker
  • Emerge as lava.
  • Creating new crust upon cooling.
  •  A mid-ocean ridge boundary between two tectonic plates.
  • consequently is termed a divergent plate boundary.
  • It connected & form a single global mid-oceanic ridge system.
  • That is part of every ocean.
  • There are  the longest mountain range in the world.
  •  The continuous mountain range is 65,000 km long.
  • The total length of the oceanic ridge system is 80,000 km.

  • Mid-ocean ridges are active, with new magma.
  • The crystallized magma forms new crust of basalt gabbro.
  • Oceanic crust in the ocean basins is less than 200 million years old.
  • Slow spreading ridge Mid-Atlantic Ridge have large, wide rift valleys. 10–20 km.
  • fast spreading ridges like the East Pacific Rise are narrow, sharp.
A close-up showing a mid-ocean ridge topography with magma rising from a chamber below, forming new ocean plate which spreads away from ridge
Mid-ocean ridge,magma rising from a chamber below, forming new ocean plate which spreads away from ridge

  •  There are two processes;
                                                             slab pull

  • Ridge-push= growing bulk of the ridge.
                                        pushes the rest of the tectonic plate away from the ridge
                                        towards a subduction zone.
  • Slab-pull =    this is simply the weight of the tectonic plate.
                                      subducted (pulled) below the overlying plate.
                                      dragging the rest of the plate along behind it.

  • The other process contribute to the formation of new oceanic crust at mid-ocean ridges is the "mantle conveyor".

  • Mid-ocean ridge creates new material spreading rate measured in mm/yr.
  • The common subdivisions of spreading rate;

                                                            >100 mm/yr
                                                           100–55 mm/yr
                                                           55–20 mm/yr

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