When stuck rocks underground suddenly slip, what travels outward?

• Sunlight shining through the layers of buried rock
• Air carrying sound through an empty underground tunnel
• Energy that shakes the surrounding ground

What rock movement can start an earthquake?

• Sunlight slowly warming rocks on a hillside
• Underground rocks suddenly slipping or breaking
• Ocean waves washing loose stones onto a beach

Shaking can reach places away from where rocks suddenly moved underground.

Rocks slip underground. Their energy reaches Jay's classroom and the floor shakes. Which part is an effect felt at the surface?

• The rocks sticking before the sudden slip
• The rocks storing energy before they move
• The classroom floor shaking under Jay

Rocks suddenly slip along an old underground crack. No new crack forms. What can this slip start?

• Only a slow change with no shaking
• An earthquake that sends shaking outward
• Only a crack that must reach the surface

Rocks can store energy while they are stuck, before they suddenly slip.

One earthquake shakes a nearby town strongly and a farther town lightly. Which explanation could account for the difference?

• The farther town's people must have imagined shaking
• Shaking can weaken as it travels through the ground
• Every town receives exactly the same amount of shaking

Zara says, "My house shaking made the rocks underground slip." Which explanation matches the lesson?

• The rocks slipped and sent shaking to her house
• Her house shook and pushed the buried rocks apart
• The rocks could only slip after everyone felt shaking