Final answer:
The Richter scale is used to quantify the energy produced by an earthquake. A magnitude-4.0 earthquake releases just over 10 times more energy than a 2.0 magnitude earthquake.
Step-by-step explanation:
The Richter scale is used to quantify the energy produced by an earthquake. The numbers on the Richter scale represent the magnitude of the earthquake, which is a measure of the energy released. A magnitude-4.0 earthquake releases just over 10 times more energy than a 2.0 magnitude earthquake.