# 6: Earthquakes

• 6.0: Introduction to Earthquakes
• 6.1: Earthquake Geometry and Process
Generally speaking, it is the movement of faults that leads to earthquakes. A fault is a plane with localized displacement separating two blocks of rock. As you might already know from your intro to geology class, there are three basic types of faults; strike slip, normal, and reverse.
• 6.2: Earthquake Magnitude
In order to measure the size and intensity of earthquakes, we have devised several scales to measure them. The Richter Magnitude scale is one such scale which you have likely heard of.
• 6.3: Location and Focal Mechanisms
To find the simplified location of an earthquake there are four basic steps. Identify seismic wave phase arrival times at stations, calculate distance between individual stations and the epicenter, triangulate-use determined distances for multiple stations to locate epicenter, and calculate origin time.
• 6.4: Earthquake Distance and Magnitude Jupyter Notebook
An interactive example of calculating the distance from an earthquake from seismic wave arrivals and magnitude from the empirical formula for Richter Magnitude. This page walks you through using a seismogram to calculate the seismometer's distance from an earthquake and using that to calculate earthquake magnitude.
• 6.5: Earthquake Scaling Laws
There is a quantitative way of looking at the distributions of the occurrence of different magnitude earthquakes, the Gutenberg-Richter frequency-magnitude scaling law.
• 6.6: Summary