📊 Part 1: Understanding Seismographs

Background: A seismograph is an instrument that measures and records earthquake waves. The wavy lines show how much the ground shook during an earthquake.

1. Look at the seismograph reading below. What does the flat line at the beginning represent?

Seismograph A: ________/\/\/\/\/\/\/\/\________

No earthquake activity

A very strong earthquake

The seismograph is broken

Underground water movement

2. Compare these two seismograph readings. Which earthquake was stronger?

Reading B: ___/\/\/\___

Reading C: ___/\/\/\/\/\/\/\/\___

Reading B shows a stronger earthquake

Reading C shows a stronger earthquake

Both earthquakes were equally strong

3. What information can scientists learn from seismograph readings? (Check all that apply)

When the earthquake started

How strong the earthquake was

The weather during the earthquake

How long the earthquake lasted

📏 Part 2: The Richter Scale

Richter Scale Reference:

• 1.0-2.9: Not felt by people
• 3.0-3.9: Felt slightly by some people
• 4.0-4.9: Felt by many people, dishes rattle
• 5.0-5.9: Felt by everyone, some damage to buildings
• 6.0-6.9: Strong earthquake, moderate damage
• 7.0-7.9: Major earthquake, serious damage
• 8.0+: Great earthquake, widespread destruction

4. An earthquake measures 5.2 on the Richter scale. What would people likely experience?

5. Fill in the blanks: An earthquake that measures _______ or higher on the Richter scale is considered a major earthquake that can cause serious damage.

6. Match the Richter scale reading with the correct description:

2.5

4.8

7.1

Major earthquake

Not felt by people

Dishes rattle

🔬 Part 3: Analysis and Application

7. Draw what you think a seismograph reading would look like for a magnitude 3.0 earthquake compared to a magnitude 6.0 earthquake:

8. Explain why seismographs are important tools for scientists who study earthquakes. Use at least two specific reasons in your answer.

9. If you lived in an earthquake-prone area, what magnitude earthquake on the Richter scale would make you concerned about safety? Explain your reasoning.