World Geography Questions

Saigon

Mason–Dixon line

Dubai

The Earth has four major systems or spheres. These systems are

 1. The geosphere,

 2. The hydrosphere,

 3. The atmosphere, and 

4. The biosphere.

The biosphere is the system where we belong.

Tectonic plates are pieces of Earth's crust and uppermost mantle, together referred to as the lithosphere. These plates which float on and travel independently over the mantle and much of the earth's seismic activity occurs at the boundaries of these plates.

The seven major plates are the African plate, Antarctic plate, Eurasian plate, Indo-Australian plate, North American plate, Pacific plate and South American plate.

Volcanoes usually form along plate boundaries , where tectonic plates are either moving towards or away from one another. They may be convergent or divergent.