Earthquakes cause varying levels of damage to cars and homes in the areas they impact.
Earthquakes can be strange and scary to children as well as adults. Studying them can be exciting and informative. Teach the children in your class measure earthquake magnitude with a simple, hands-on exercise that helps them understand apply modified Mercalli intensity (MMI) values to written descriptions of an earthquake. At the end of the lesson, students should understand how scientists measure the size and strength of earthquakes.
Instructions
1. Ask students whether they've every been awakened suddenly out of a deep sleep in the middle of the night. Explain that this is what it feels like to experience an earthquake, discussing how sometimes earthquakes can be so small that people hardly feel them, while others are so strong that people cannot ignore them. Tell the students that scientists called seismologists use something called a modified Mercalli intensity (MMI) scale to measure the size of an earthquake, vibrations felt by those who experienced the quake and the damage caused by the shaking.
2. Explain the concepts of magnitude and intensity. Invite the students to compare the terms and consider which measurement seems more useful to know about an earthquake.
3. Give students a description of the MMI scale and the first two handouts linked in the Resources section. Explain that the handouts describe the Northridge, California, earthquake of 1994. Tell students that the earthquake measured 6.7 but its effects varied throughout the area affected by the quake. Ask students to analyze responses from people who lived through the earthquake, then attempt to determine on a map where those people lived based on their description of the quake.
4. Instruct students to color the intensity key at the bottom of Handout 1 with colored pencils, using increasingly darker colors for more intense values. Tell students to read Handout 2 and assign an MMI rating of 1-X+ to each description. Ask students to color in the zip codes on Handout 1 according to their intensity scale and place a title on the map.
5. Discuss together why students rated experiences the way they did and why they colored their maps as they chose to. Pass out Handout 3 (see link in Resources section) to the students, and ask them to compare their maps with the standard (Handout 3). Discuss how their maps compared with the USGS's map.
6. Expand the activity by asking students to pretend to be explorers on a mission to determine an MMI ranking for the New Madrid earthquakes of 1811 and 1812 (see link in Resources section) and summarize in writing what one of the towns affected by the quakes experienced. Tell them that their reports must explain why they assigned the intensity level they did to the quake. Assess the students' understanding of magnitude and intensity based on the quality of their written explanations.
Tags: Resources section, Tell students, their maps, Explain that, intensity scale
