New crust is continually being pushed away from divergent boundaries (where sea-floor spreading occurs), increasing Earth's surface. But the Earth isn't getting any bigger. What happens, then, to keep ...

Plate tectonics is the theory that Earth's outer layer is made up of plates, which have moved throughout Earth's history. The theory explains the how and why behind mountains, volcanoes, and ...

When the plate sinks into the mantle it melts to form magma. The pressure of the magma builds up beneath the Earth's surface. The magma escapes through weaknesses in the rock and rises up through a ...

The initiation of plate tectonics on Earth is a critical event in our planet’s history. The time lag between the first proto-subduction (about 4 billion years ago) and global tectonics (approximately ...