How Earthquakes Happen

When we least expect it, when we're least prepared disaster can strike. and few disasters are as unsettling as an earthquake. My guess is that earthquakes are really so scary because you don't have any warnings It's the only thing besides a nuclear war that can really... one second you're living in a big beautiful city and ten seconds later it's flat Every day the earth is shaken by hundreds of small earthquakes Most go unnoticed. They usually occur along the boundaries of the thin plates that cover the earth like an eggshell. Driven by the heat, deep within the earth's core the plates grind against each other on long lines called faults. When the plates find their motion blocked, stress builds up Finally the fault gives way The released energy raises through the in the form of sismic waves For much of the world, the movement of plates like these is also an indispensable creative force. If we didn't have earthquakes, if we didn't have this great flow of heat from the interior of the earth the earth would be a cold dead place. If it wasn't for this great flow of heat, there'd be no continents, no oceans, no atmospheres The earth would be as dead and dry and cold as the moon. It's really the earthquake that creates the topography, the valleys, the mountains Earthquakes have been shaping landscapes for eons It's only in the last few hundred years that civilization has gotten in the way and when it does ...