: When mantle rock melts due to changes in pressure or composition, it becomes magma. This magma rises to the surface, creating new landmasses and releasing gases that helped form our atmosphere.
The mantle is approximately 2,900 kilometers (1,802 miles) thick and is primarily composed of rocks rich in magnesium and iron, such as . While it is solid rock, it behaves like an extremely viscous fluid over millions of years—a property known as plasticity. It is generally divided into three main sections: Earth’s mantle is
: Extending from the crust to about 410 km deep, it includes the lithosphere (the rigid top layer) and the asthenosphere , a semi-fluid zone that allows tectonic plates to slide. : When mantle rock melts due to changes
: Heat from the core creates convection currents in the mantle. These currents act like a conveyor belt, moving tectonic plates, creating mountains, and causing earthquakes. While it is solid rock, it behaves like