Earthquakes release energy as seismic waves. A seismometer records ground motion at its site. Magnitude describes the source size; intensity describes shaking effects at a place. One earthquake can produce different intensities at different places. A bigger magnitude number is not a linear multiplier of damage. Safety: No live earthquake feed, shaking test, or emergency advice. Diagram numbers are illustrative. Stop: Stop at the fictional report. Do not shake furniture, seek tremors, or assign a magnitude from a homemade trace.

Materials: Paper; Pencil; Ruler 1. Draw an illustrative trace on a grid: across positions 0 to 8, plot vertical values 0,0,1,-2,3,-1,1,0,0. Join in order. Label horizontal axis Time steps, vertical axis Invented motion units. This is not a real seismogram and cannot be converted to magnitude. 2. Draw a small star underground with three expanding rings around it. Label Energy travels outward in waves. Draw two recording stations at different places and connect each to a small trace box. 3. Copy fictional report cards: Event A moment magnitude 4.0; Event B moment magnitude 6.0. For Event B, town Near reports intensity VI; town Far reports intensity III. Sort source-size statements and place-effects statements into separate columns. 4. Write three conclusions: which event has larger source size; whether Event B needs a different magnitude at town Far; and why your invented trace cannot tell an event magnitude. Use the instrument, waves, and the source/place distinction in your explanation. Done: The labelled invented trace, wave diagram, two-column report sort, and three conclusions are complete. Proof: Keep all diagrams and sorted cards. Note help plotting negative values, reading Roman numerals, or explaining source versus site. Stop: Stop at the fictional report. Do not shake furniture, seek tremors, or assign a magnitude from a homemade trace.