When the explorer Ferdinand Magellan finally made it ‘round the treacherous horn of South America in 1521, the ocean beyond seemed especially calm—so he named it the peaceful sea: Mare pacificum, the Pacific Ocean.

Little did he know the Pacific is anything but. It’s surrounded by more than 1,000 volcanoes that make up what’s now called the Pacific Ring of Fire—a geologically active strip 25,000 miles long, in places 300 miles wide, that borders the Pacific on three sides.

It would be more than 400 years later, in 1960, that scientists could understand what was going on: almost the entire periphery of the Pacific Ocean consists of plate boundaries where tectonic plates slide against or are pushed under other plates.

Whenever this happens, extraordinary energy is released.

Two-thirds of Earth’s volcanic eruptions since the last Ice Age have happened in the Pacific Ring of Fire, including famous ones like Mount St. Helens.

Ninety percent of the world’s earthquakes each year happen along the edges of the Pacific.

This includes massive events, like the Tōhoku quake that caused the tsunami that flooded the Fukushima nuclear plant.

Of course, the Pacific is also vital for navigation and trade, fishing and national economies and provides a livelihood for millions of people.

Like most things in life, there are pros and cons.