GEOG 1350 Lecture Notes - Lecture 2: San Andreas Fault, Richter Magnitude Scale, Aseismic Creep

• School: University of Guelph
• Department: Geography
• Course: GEOG 1350
• Professor: Jaclyn Cockburn

Document Summary

They result from the rupture of rocks along a fault. Energy from an earthquake is released in the form of seismic waves. They are mapped according to the epicenter; the focus is located directly below the epicenter. They are measured by seismographs and compared by magnitude. The actual earthquake happens at the focus, which is always along the fault, where the rapture occurs. The energy from the rapture comes out in waves. The magnitude of an earthquake is expressed as a number to one decimal place. Richter first developed this type of measurement in 1935. The richter scale was a measure of the strength of a wave at a distance of 100 km from the epicentre. We no longer use the richter scale as since then more accurate methods have been developed. Today, earthquakes are measured using the moment magnitude scale (m). The elasticity of the crust at the focus.