A Ring Around an Ocean
The Pacific Ring of Fire is one of the most dramatic features on our planet. Despite its fiery name, it is not a ring of flames. It is a vast zone that traces the edges of the Pacific Ocean, and it is famous as the most geologically active region on Earth, home to most of the world's earthquakes and volcanic eruptions.
The Shape of the Ring
The Ring of Fire is not a perfect circle. It is shaped more like a giant horseshoe, an enormous belt tens of thousands of kilometers long. It runs up the western side of South and North America, crosses near Alaska, and then travels down the eastern edge of Asia, passing through countries such as Japan, and continuing toward New Zealand. In effect, it outlines the rim of the entire Pacific Ocean.
Why So Much Activity Happens There
The reason for all this activity lies beneath the surface, in plate tectonics. The Earth's outer shell is broken into huge slabs called tectonic plates, which slowly move. Around the Pacific, the edges of several of these giant plates meet. Where plates collide, pull apart, or grind past one another, they create enormous stress. This is released as earthquakes, and it allows molten rock to rise and form volcanoes.
A Zone of Earthquakes and Volcanoes
The result is striking. A very large share of the world's earthquakes happen along the Ring of Fire, including many of the most powerful ones ever recorded. It also contains a huge portion of the world's active volcanoes. This is why countries located on the Ring of Fire, such as Japan, Indonesia, and Chile, must live with the constant possibility of earthquakes and eruptions.
Source
This article was written using information from Wikipedia.