ECN 510 Chapter Notes - Chapter 2: Epicenter, Canadian Shield, Subduction
Document Summary
Earthquakes result from the rupture of rocks along a fault. Fault a fracture in the earth"s crust. Seismic waves the energy formed when rocks on opposite sides of the fault move. Epicentre the point on the surface directly above the fault rupture. Richter scale a decimal number on a scale that represents the size or magnitude of a quake. Magnitude and frequency of earthquakes: see table 2. 3 on page 34. The intensity depends on magnitude, distance from epicenter, and the nature of the ground at the site. Modified mercalli intensity scale: measures the degree to which an earthquake affects people, property, and the ground, usually shown on maps, based on newspaper articles, reports of damage assessment teams, and questionnaires to residents. Compared to sliding two rough boards past each other two lithospheric plates move past each other. This rupture produces vibrational energy called seismic waves. Fault types: strike-slip faults: displacements are mainly horizontal, dip-slip faults: displacements are mainly vertical.
