Assuming their condition to be the basis, earthquakes have been mainly classified into two types:
1. Terrestrial earthquakes
2. Oceanic earthquakes.
1. Terrestrial Earthquakes: Earthquakes experienced on land are known as terrestrial earthquakes. Earthquakes evolving in Mid – Continental belt usually are of this category.
2. Oceanic Earthquakes: Earthquakes which evolve in the oceans are known as oceanic earthquakes. Oceanic waves are formed in the oceans from these types of inter-oceanic earthquakes. These oceanic waves are known as Tsunami. These types of oceanic waves usually prove to be extremely destructive in coastal regions. The tsunami which evolved due to a violent earthquake which had hit the region near Honshu Island in Japan had destroyed the entire Fukushima city.