1. Formation of Oceanic Ridges: At mid-ocean ridges, magma rises from the Earth's mantle and cools to form new oceanic crust. This process pushes the existing oceanic crust away from the ridge, creating a "push" force.
2. Gravity and Weight: The newly formed oceanic crust is hot and buoyant, but as it moves away from the ridge, it cools and becomes denser. This density increase causes the oceanic plate to sink slightly, increasing its weight.
3. Downward Force: The weight of the cooled and denser oceanic plate exerts a downward force on the plate, pushing it away from the ridge and towards a subduction zone.
4. Subduction Zone: At a subduction zone, one tectonic plate (usually an oceanic plate) slides beneath another (either an oceanic or continental plate). This is where the ridge push force is most significant.
In summary: Ridge push is a continuous process that results from the cooling and sinking of oceanic crust as it moves away from the mid-ocean ridge. This weight pulls the plate towards a subduction zone, contributing to the overall movement of tectonic plates.
It's important to note: Ridge push is not the only force driving plate tectonics. Other factors like slab pull (the gravitational force pulling the denser subducting plate down) and mantle convection (the movement of hot material within the mantle) also play significant roles.
