Lesson 1: Earthquake Risks – Dutch learned how earthquakes are measured. The Richter scale is a numerical rating system that measures the energy of the largest seismic waves produced by an earthquake which are measured with a seismograph. This scale uses the amount of ground motion at a given distance from an earthquake to determine magnitude. Each increase of one unit on the Richter scale represents 10 times the amount of ground motion. Then he learned about the moment magnitude scale which is a rating scale that measures the energy released by an earthquake, taking into account the size of a fault, the motion along the fault, and the strength of the rocks that break during an earthquake. This scale uses newer technology to produce more accurate measurements. The modified Mercalli scale measures the intensity of an earthquake based on descriptions of its effects on people and structures. This scale ranges from I to XII. Then he learned that the epicenter is the point on Earth’s surface directly above where the energy from an earthquake is first released.
Assignment: Add pictures of seismograph and comparison of Richter, Mercalli, and Moment Magnitude Scales to measure earthquakes to science notebook.