Daniel wants to know why Japan gets so many earthquakes while where he lives barely feels any.

The answer starts underneath his feet.

The Earth's crust is not one solid piece. It is broken into enormous sections -- like a cracked eggshell -- and they are all moving. Slowly. All the time. About as fast as your fingernails grow. Where those sections meet is where earthquakes happen. Japan lies along the boundaries of four major tectonic plates -- very few places on Earth sit at the meeting of so many.

Around the Pacific Ocean, many of Earth's most active plate boundaries are concentrated in a zone called the Ring of Fire -- a horseshoe-shaped belt roughly forty thousand kilometers long. About ninety percent of all earthquakes happen there. Japan, California, Chile, Indonesia, New Zealand -- all sitting on or near that ring. And ro ...