Close your eyes and picture an active volcano. Can you hear the explosion? See the fire spewing? Smell the gases? Feel the ground tremble? Taste the ash in your mouth?
Now picture this happening in your backyard. For the residents of the villages on the slopes of Mount Etna, this is a reality they know all too well. Perhaps they knew what to expect when they settled on Mount Etna, the mythical home of Vulcan, the Roman god of fire and metalworking. Mount Etna, on the Italian island of Sicily, is the tallest volcano in Europe, and also one of the most active. Nicknamed the "friendly giant," Etna has been erupting for half a million years.
From October 2002 to January 2003, Mount Etna had one of its most explosive eruptions of the past one hundred years. Despite its half a million years of activity, Mount Etna is not considered a killer volcano. Etna keeps its explosive eruptions rare and close to its top, and its lava moves very slowly down its flanks, giving people a chance to escape. But even though Etna is anything but a killer volcano, as with any volcano, it has a high destructive potential. Just how does a volcano become destructive?
Deep inside the earth, there is a solid body of rock called the mantle. The movement of the earth's crust produces high temperatures and pressure, creating molten rock called magma. The magma then rises through the denser rock layers toward the earth's surface. It keeps moving through the crust until the pressure of its movement upward meets a stronger downward pressure from the surrounding solid rock. At this point, the magma collects in chambers below the surface of the earth.
If the magma pressure rises to a high enough level or a crack opens up in the crust, the molten rock will spew out of the earth's surface. Gases and rock shoot up through the opening and spill over or fill the air with lava fragments. Eruptions can cause lava flows, hot ash flows, mudslides, avalanches, falling ash, and floods. Volcano eruptions can knock down entire forests, or even trigger tsunamis, flashfloods, earthquakes, mudflows, and rock falls.
Although scientists know a great deal about these forces of nature, their destructive power and unpredictability make them both awesome and fearsome, reminding the 500,000,000 people who live near volcanoes that the earth is very much alive!