geology

plate tectonics

plate tectonics ('tectonics' means 'building') is the name of the scientific theory that states that the crust is made up of 12 major plates and that these plates are moving at different speeds and directions. Their movements cause earthquakes and volcanism. The places where two plates meet is called a plate boundary. Earthquakes and volcanoes are most likely to occur either on or near plate boundaries.


inside the earth

The earth is made up of four district layers, the outer most layer of the earth is called the crust, in geology, the crust is the outer most solid shell of a rocky planet, dwarf planet or natural satellite. It is usually distinguished from the underlying mantle by its chemical makeup.
The crust is the thinnest layer between 0-60km thick. The crust is the solid rock layer upon which we live, there are two different types of crust: continental crust, which carries land, and oceanic crust, which carries water. continental crust is thicker than oceanic crust.


power to move plates

Tectonic plates are floating on a layer of molten (liquid) rock - the mantle. The mantle near the core is much hotter than the mantle near the crust. The temperature difference sets up convection currents and causes the movement of the tectonic plates.


plate boundaries

Divergent boundary: divergent boundaries occur when two plates pull apart, new crust is created as the plates pull away from each other when a diverging boundary occurs on land a rift separating over time, and the mass of land will break into smaller parts.

convergent boundary: convergent boundaries occur when two plates come together when oceanic crust collides with continental crust, the denser oceanic crust is destroyed and recycled back into the interior of the earth when two continental crusts collide neither plate may subduct and mountains may form as both plates are pushed together

transform plate: Transform boundaries occur
when two plates slide past each other. Most transform faults are found in the oceans. However, a few of them occur on land.