화산은 어떻게 태어나는가

Deep Beneath Our Feet

Have you ever wondered how a mountain first begins? Far below the ground where you walk, the Earth hides a fiery secret. The heat comes from deep inside our planet. Deep down, the rock grows so hot that some of it slowly melts. This melted rock is called magma, and it glows a bright orange-red. Magma is lighter than the solid rock that surrounds it on every side. Because it is lighter, the glowing magma begins its long journey upward.

A Crack in the Ground

As the magma pushes toward the surface, it searches for a weak spot. Sometimes it discovers a thin crack in the Earth's hard, rocky crust. The crack becomes a doorway. The magma squeezes into this opening and creeps closer to the open air. Pressure builds beneath the ground, much like air trapped inside a shaken bottle. Before long, the rock can no longer hold all of that pressure back.

The First Eruption

With a mighty roar, the young volcano erupts for the very first time. The ground shakes and rumbles. Red-hot lava bursts out of the opening and spills across the land. Ash, steam, and burning rocks shoot high into the darkened sky. It is a powerful and amazing sight. When the lava meets the cool air, it hardens into solid black stone. Each eruption leaves a fresh new layer of rock behind on the ground.

Building a Mountain

A single eruption is almost never the end of the story. The volcano rests, then erupts again and again over many long years. Every layer of cooled lava stacks neatly upon the layer below it. Little by little, these layers pile up into a tall, steep cone. Some cones grow gentle and wide, while others grow sharp. After a very long time, a brand-new mountain rises where flat land once lay. This tall mountain is a true volcano.

A New Island Is Born

Some volcanoes are born deep beneath the rolling ocean waves. Their lava piles higher and higher across thousands and thousands of years. At last, the growing peak breaks through the water and touches the sky. A brand-new island appears, built entirely from cooled volcanic rock. Waves crash against the young shore. Once, there was only sea, and now dry land waits for its first plant. What other wonders might the restless Earth be quietly building right now?