Seismic Waves & Earth's Interior
CONCEPTUALDistinguish between P-waves (compression, travel through solids and liquids) and S-waves (shear, cannot pass through liquids); explain why a seismic shadow zone exists on the far side of an earthquake; describe how seismologists use wave refraction and reflection to infer that Earth has a solid inner core, liquid outer core, mantle, and crust
Mastery Evidence
Assessment Prompt
“Can [child] explain how scientists know Earth has a liquid outer core if nobody has ever drilled that deep — what clues do earthquake waves give us about Earth's hidden interior?”
Prerequisites1
- Measuring Earthquake StrengthhardAges 9—11
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- Measuring Earthquake Strength hard
Seismic wave types and Earth interior depends on seismometer and earthquake measurement concepts
- What Is an Earthquake soft
Quick/slow changes concept benefits from earthquake as example of quick change
- Shapes of land and water soft
Mapping volcano/earthquake patterns benefits from knowing about landforms like mountains and valleys
- Days, Weeks, Months & Years soft
Observing and describing seasonal changes requires basic date and time vocabulary (months, seasons, year)
- Ordering Events in Time hard
Understanding days/months/years builds on sequencing events chronologically
Unlocks3
- Drawing conclusions from evidence (age 12+)softAges 12—13
- Supervolcanoes & Volcanic WinterhardAges 12—13
- How Tectonic Plates MovehardAges 11—12