2.1 Distribution of earthquakes and volcanoes

Earthquakes and volcanoes are not randomly distributed across the globe. They tend to occur in distinct patterns, primarily along the boundaries of the Earth's tectonic plates. The most notable pattern is the Pacific Ring of Fire, which is home to over 75% of the world's volcanoes and experiences the most earthquakes. 

There are two types of crust: oceanic or continental. Oceanic plates are denser and thinner, while continental plates are less dense and thicker. When the plates move, it leads to tectonic activity such as earthquakes and volcanoes. 

Constructive: the plates move apart constructing new crust.

Destructive: the plates move together, destroying crust.

Conservative: plates slide past each other

The global distribution of volcanoes correlates closely with the edges of these plates, particularly along the boundaries where plates come together or move apart. The Pacific Ring of Fire, a horseshoe-shaped area in the Pacific Basin, featuring over three-quarters of the world's active and dormant volcanoes.

Some volcanos occur at 'hot spots'. These are plumes of hot material that rise from deep within the mantle to create volcanoes in the middle of tectonic plates, such as the Hawaiian Islands. 

• All earthquakes and volcanoes occur at the edges of tectonic plates.

• Larger tectonic plates are more prone to earthquakes and volcanic activity.

• Human activities have no impact on the occurrence of earthquakes and volcanoes.