In other languages
French: seisme, German: erdbeben, Italian: terremoto, Spanish: terremoto, Dutch: aardbeving, Portuguese: Terremoto.
A powerful quake, but has no effect on flying foes. Hits everyone on the field, excluding the user.
Earthquake does damage.
In Generation II and III, Earthquake does double damage if the opponent is in the semi-invulnerable stage of Dig.
By leveling up
In Generation III, Earthquake is TM26.