WHAT ARE EARTH QUAKES?
Earth quakes are the vibrations underground caused by stress rocks. An earthquake is a sudden shaking or big vibrations of the ground made in the earth's crust when rocks rub together and build up a sudden rupture, and then rebound. The vibrations can range from barely noticeable to a humongous destruction where the surface of the Earth can be shaped by thrusting up cliffs or opening great cracks in the ground.
|
HOW CAN EARTHQUAKES OCCUR?Earthquakes are caused by sudden movements along fault lines in the earth's crust. A fault is a crack or burst in the earth along which rocks on each of it's two side move past each other. There are two kinds of earthquakes, tectonic(plates that make up the earth's crust cause a fault) and subduction-zone quakes (one plate slides beneath the other plate). Subduction-zone quakes account for nearly half of the world's destructive seismic events and 75 percent of the earth's seismic energy.
|