The USGS currently reports earthquake magnitudes using the Moment Magnitude scale, though many other magnitudes are calculated for research and comparison purposes. The Richter scale measures the largest wiggle (amplitude) on the recording, but other magnitude scales measure different parts of the earthquake. The Richter scale is an outdated method for measuring magnitude that is no longer used by the USGS for large, teleseismic earthquakes. It is a measure of the size of the earthquake source and is the same number no matter where you are or what the shaking feels like. There are many different ways to measure different aspects of an earthquake: That vibration pushes the adjoining piece of ground and causes it to vibrate, and thus the energy travels out from the earthquake hypocenter in a wave. The slip of one block of rock over another in an earthquake releases energy that makes the ground vibrate.
Each seismic station in the network measures the movement of the ground at that site.
Earthquakes are recorded by a seismographic network.