(1) On May 18, 1980, Mount St. Helens sent an explosion of ash, gas, and rock into the sky. This eruption led to the death of 57 people, in addition to permanently changing the surrounding landscape. It is still one of the most disastrous volcanic eruptions in recent history.

(2) Mount St. Helens is located in the Cascade Mountain Range in Washington, United States. It is part of the Ring of Fire, an important geological area. This area is home to over 160 active volcanos. Volcanos are active if they have erupted at least once in the last 10,000 years. Mount St. Helens is a stratovolcano. This means it is a steep, evenly shaped cone made of many layers of volcanic rock and ash. These volcanos often have explosive eruptions.

(3) Before the eruption of Mount St. Helens, a bulge of rock formed on the northern side of the mountain. Then, early on May 18th, an earthquake occurred that was caused by increasing pressure inside the mountain. This led to a landslide. The force of the landslide collapsed the entire northern side of the mountain, which led to a lateral blast. Lateral blasts occur when volcanos erupt sideways, rather than at the peak. This lateral blast sent rocks flying for miles at high speeds. These blasts destroy forests, buildings, and other structures in a short amount of time. The lateral blast at Mount St. Helens destroyed an area of about 150 square miles. It destroyed forests and left debris in three-inch layers, making the situation even more disastrous.

(4) When Mount St. Helens erupted, clouds of deadly ash, volcanic rock, and pyroclastic flows flew outward from the volcano. Pyroclastic flows are more dangerous than lava flows. They are made of gas and volcanic matter. The temperature inside one can reach 1832 °F. They move at a speed of more than 50 miles per hour. It is impossible for humans and animals to outrun them. These flows make the eruption of stratovolcanos deadly. As a result, the forests covering the mountain were ruined. Fortunately, there weren't any towns near enough to be destroyed.

(5) By the time Mount St. Helens finished erupting, a crater had formed at its top. Forests had been destroyed for miles and rivers had been blocked by debris. Clouds had even blocked out the sun in the entire state. It took years for the environment to recover.