A magnitude 7 or higher can destroy a city.
You would feel the ground shake in a magnitude 3 quake.
You may not notice a magnitude 2 quake.
Each year, there are about a million earthquakes around the world. But only about 100 of these cause serious damage.
An earthquake can trigger a volcano to erupt.
The deadliest known quake in history shook China in 1556, taking about 830,000 lives.
4 out of 5 of the world's earthquakes take place along the rim of the Pacific Ocean, a zone called the Pacific Ring of Fire.