Earthquakes
Earthquakes happen when the earth's crust suddenly breaks along a fault. The release of energy caused by the break triggers seismic waves that make the ground shake. Earthquakes happen at all the boundaries. There are 3 faults and 3 types of seismic waves (these are discussed in more detail on a separate page). Earthquakes are natural disasters that happen every day and we have no control over. Do you think a earthquake is happening under your feet right now? Small earthquake happens all time, you just don't feel them. You most likely have a million questions in your head, KEEP READING!!!
Locating An Earthquake
To locte on earthquake you have to you a seismograph. A seimograph is a graph that tells you when an earthquake is happenig. The graph has a little arm on it that is like a pen and when it feels a seismic wave it writes zigzag like lines. The graph helps scientists find where the earthquake starts. An eathquake starts at a focus under the earths surface. Where the faults slip the focus occurs. The focus is where the seismic waves come from. Right above the focus is the epicenter. The epicenter is where the earthquake is felt the strongest.
The video is telling you about the seismograph and a little about faults.