At a mid-ocean ridge, the two tectonic plates move apart from each other. This is called divergent plate movement.

Here's a breakdown:

* Magma from the Earth's mantle rises up: The intense heat from the Earth's mantle causes molten rock (magma) to rise.

* New oceanic crust is formed: As the magma reaches the ocean floor, it cools and solidifies, forming new oceanic crust.

* Plates move away: The newly formed crust pushes the existing plates apart, causing them to move in opposite directions.

This process is responsible for the creation of new ocean floor and the widening of ocean basins over time.

Key features of mid-ocean ridges:

* Volcanic activity: The rising magma creates underwater volcanoes.

* Earthquakes: The movement of plates causes earthquakes along the ridge.

* Hydrothermal vents: Hot, mineral-rich water escapes from the ocean floor, supporting unique ecosystems.

Let me know if you have any other questions about plate tectonics!