A tragic hero can be defined simply as the protagonist of a tragedy. The Greek philosopher Aristotle, however, endowed this individual with a number of specific characteristics. The first of which is his ability to evoke fear and pity from an audience.
Earthquakes are caused by either volcanic activity or shifting of massive tectonic plates underneath the surface of the earth. The plates have a ton of pressure and are pressing against each other, and when the plates suddenly shift it causes the entire ground to move, shake or break apart.
P and S waves may seem like shaky business, but the waves that really do damage are the ones that occur when the energy of the quake reaches the surface of the earth. Rayleigh waves churn over and under like rolling ocean waves; Love waves shake the earth from side to side.