When you hear of an earthquake, you usually hear its intensity described using a number.
To most, that number represents the strength of the earthquake, or how much damage the shifting tectonic plates created.
To the scientists who study earthquakes, it’s only part of the equation.
When an earthquake hits anywhere in the world, the U.S. Geological Survey assigns it a number — called magnitude — to indicate the amount of energy released from the event.
What is magnitude, how do you measure an earthquake and how does that energy move? Here’s what we know now.
What is magnitude?
That number is called the magnitude of the earthquake, and it represents the amount of energy that is released when an earthquake occurs.
An earthquake’s magnitude is measured by a network of stations with equipment (seismographs) designed to measure the movement of the ground at that site.
In the United States, the seismographic network stretches from a point near the Bearing Sea in …