The lithosphere is made of tectonic plates. These plates move around the Earth's surface, constantly drifting apart and crashing together. There are 12 tectonic plates in total. These 12 plates float on the liquid magma of the asthenosphere and are currently moving in all different directions at all different speeds. The places where the plates are moving together are called subduction zones. This is where the lithosphere is destroyed. At the other side, where the plates are moving apart, new lithosphere is created. These places are also called destructive and constructive boundaries, respectively.

This movement of tectonic plates; as well as the destruction and construction of new lithosphere affects humans on the Earth's surface. It does this by creating volcanoes, mountains, and earthquakes.

Volcanoes are formed either when two plates move apart or when two plates collide. Volcanoes are a landform that is produced as lava cools. There are two main types of volcanoes: shield volcanoes and composite volcanoes. Shield volcanoes are made from mafic lava, have very gentle slopes and are found at constructive plate margins (where the plates are moving apart). An example of a shield volcano is the Hawaiian Islands. Composite volcanoes on the other hand are from felsic (sandy) magma, are found in subduction zones (where the plates are moving together) and are high layered constructions. They are very explosive and are much more dangerous than shield volcanoes. An example of a composite volcano is Mount Pinatubo. Volcanoes have many effects on humans. They create islands that people may live on or use to gather resources. They threaten towns and cities that choose to build near them. They have caused people to abandon certain areas (such as some Hawaiian Islands) and they have wiped out whole cities (such as Pompeii). When a volcano erupts it can disrupt the lives of people all over the world as it blocks out the sun and may cause winter.

Then there are mountains, which are formed in three ways. First two plates collide creating fold mountains. This means that instead of one plate sliding under the other, they crash together and force the Earth's crust up, creating mountains. An example of a fold mountain is the Himalayas. Then there are volcanic mountains. These mountains are formed by lava accumulation in places where two plates are moving away from each other. An example of volcanic mountains is Hawaii. Finally there are fault mountains that are formed

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