Seismographs and Waves

Unit: Exploring Earth's Layers

Lesson 3 of 5
Duration: 45 minutes
Grade: 8th Grade
Class Size: 30 students

Learning Objectives

By the end of this lesson, students will be able to:

I can explain how seismographs detect and record seismic waves.
I can identify and differentiate between P-waves and S-waves on a seismogram.
I can interpret seismogram data to infer the location of an earthquake relative to the seismograph.
I can describe how seismic waves provide evidence about the Earth’s internal structure.

Common Core State Standards Alignment

While Common Core State Standards primarily focus on Math and English Language Arts, this science lesson connects deeply with Next Generation Science Standards (NGSS) for 8th grade and ELA standards for scientific literacy, which align well with Common Core expectations in reading and data interpretation:

Science Standards (NGSS aligned)

MS-ESS2-3: Analyze and interpret data from seismograms to determine the epicenter and characteristics of earthquakes.
MS-ESS3-1: Apply scientific ideas to map the impacts and locations of earthquakes using real data.
MS-ESS2-2: Construct explanations for how seismic waves reveal Earth's layers.

ELA/ Literacy Standards (Common Core)

RST.6-8.3: Follow precisely a multistep procedure when carrying out experiments, taking measurements, or performing technical tasks.
RST.6-8.7: Integrate quantitative or technical information expressed in words in a text with a version of that information expressed visually (e.g., in a flowchart, diagram, model, graph, or table).
WHST.6-8.2: Write informative/explanatory texts to examine a topic and convey ideas clearly.

Materials Needed

Model or video demonstration of a seismograph
Sample seismogram charts with clear P-wave and S-wave signatures
Graph paper and colored pencils
Projector/smartboard
Seismic waveinteractive simulation software or app (if available)
Handouts with dyslexia-friendly fonts and high-contrast colors
“I can…” statement posters displayed in class

Lesson Schedule

Time	Activity Description	Teacher Notes & Strategies
0-5 min	Engage: Hook & Question Show a short video or animation of an actual earthquake's seismic waves being recorded. Ask, “How do scientists know when and where an earthquake happens?” Purpose: spark curiosity and activate prior knowledge.	Use visuals with captions; pre-teach any complex vocabulary like "seismograph," "P-wave," "S-wave." Invite students to share ideas; use think-pair-share to encourage participation.
5-15 min	Explore: How a Seismograph Works Teacher demo or video showing a seismograph in action. Students observe parts and function. Define P-waves (primary, faster) and S-waves (secondary, slower). Use investigative questions: “Why do these waves arrive at different times?”	Use a physical model if possible or an interactive simulation. Address different reading levels by having a simplified handout with visuals and dyslexia-friendly text. Check understanding through thumbs up/down after each key concept.
15-30 min	Explain & Apply: Analyze Real Seismogram Data Students work in pairs to examine provided seismograms. Task: Identify P-waves and S-waves on the chart and mark arrival times. Use graph paper to plot wave arrival times from multiple stations (simplified data set).	Provide sentence starters and graphic organizers for note-taking. Circulate to support pairs with varied skills, using guiding questions. For struggling learners, allow oral explanations instead of writing as needed.
30-40 min	Elaborate: Determining Earthquake Location Facilitate guided discussion on how P and S wave arrival times help calculate earthquake epicenters. Show a basic triangulation method using three sample seismogram stations. Students predict the location of the earthquake on a map.	Interactive whiteboard demonstrations. Invite students to come up and plot points if comfortable. Advanced learners can calculate actual distances using simplified formulas. Scaffold reasoning for others by using step-by-step visuals.
40-45 min	Evaluate: Exit Ticket & Reflection Students write or record a short response to the prompt: “Explain how seismographs and the timing of seismic waves help us understand earthquakes and Earth’s layers.” Include one thing they found interesting or confusing.	Use dyslexia-friendly paper options or voice-to-text apps. Collect responses to inform next lessons and scaffold as needed. Close with a positive affirmation about their role as developing scientists.

Success Criteria

Students will demonstrate success when they:

Correctly identify P-waves and S-waves on seismogram samples.
Explain the function of a seismograph in simple terms.
Use arrival times to hypothesize earthquake locations with reasonable accuracy.
Communicate their understanding clearly in writing or discussion.

Differentiation Strategies

Learner Type	Strategies
Struggling readers & dyslexic students	Use dyslexia-friendly fonts, color-coded wave markings, and verbal explanations. Provide audio versions of handouts. Use paired work for peer support. Incorporate multisensory methods (touching model parts).
English Language Learners (ELLs)	Pre-teach vocabulary with visuals and gestures. Use sentence frames for discussions. Allow bilingual dictionaries.
Advanced learners	Assign calculating distances from P- and S-wave arrival times using wave speeds. Challenge with creating their own simple seismogram from a wave simulation. Encourage extended writing that connects to Earth’s internal layers.
Kinesthetic learners	Engage with physical models or movement activities modeling wave propagation. Use colored string or jump spots to represent wave fronts and arrival times.

Extension Activities for Advanced Learners

Research and summarize how modern technology improves earthquake detection and warning systems.
Create a digital presentation explaining the difference between surface waves and body waves and their effects.
Investigate and report how earthquakes have helped scientists map Earth’s core and mantle boundaries.

Assessment

Informal: Teacher observation during group work & discussions, thumbs-up/down checks.
Formal: Exit tickets assessing comprehension and communication of key ideas.
Optional: Short quiz in the next lesson reviewing wave identification and earthquake location methods.

Teacher Reflection & Notes

Monitor student engagement with technical vocabulary—reinforce often.
Use student exit tickets to identify misconceptions about wave types and data interpretation.
Plan for increased scaffolding in lesson 4 based on student ability to triangulate earthquake epicenters.
Celebrate students’ curiosity and scientific thinking to build confidence as investigators of Earth science.

This lesson emphasizes hands-on inquiry, visual supports, and interactive analysis—key to making complex seismic data accessible to 8th graders while meeting core literacy and scientific standards.

Teaching Instructions