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What do magnetic stripes reveal about a moving ocean floor?

Rock forming at an ocean ridge can preserve a record of Earth’s magnetic polarity. Alternating bands on either side of a ridge helped scientists connect magnetic reversals with seafloor spreading. Their arrangement offered a testable pattern, contributing evidence to a much larger account of how Earth’s surface moves.

8–10 min

Questions you could explore

  • Why would a matching pattern on opposite sides of a ridge matter?

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Earth and weather

Why is the sky blue, but a sunset often red?

The same Sun can light a blue afternoon and a red evening. What changes is the route its light takes through the atmosphere and which colors are scattered along the way.

3–5 min

Why is the sky blue, but a sunset often red?

Earth and weather3–5 minThe same Sun can light a blue afternoon and a red evening. What changes is the route its light takes through the atmosphere and which colors are scattered along the way.

Earth and weather

How can lines on a map show a steep hill?

A flat map can warn you that a route climbs sharply before you ever see the hill. Contour lines join places of equal height, and their spacing adds information about how quickly the ground rises.

2–3 min

How can lines on a map show a steep hill?

Earth and weather2–3 minA flat map can warn you that a route climbs sharply before you ever see the hill. Contour lines join places of equal height, and their spacing adds information about how quickly the ground rises.

Earth and weather

How can an earthquake alert arrive before strong shaking?

An earthquake alert can beat the strongest shaking to a distant location even though the earthquake has already started. Detection and communication can travel ahead of the damaging waves, but nearby places may receive little or no warning.

4–5 min

How can an earthquake alert arrive before strong shaking?

Earth and weather4–5 minAn earthquake alert can beat the strongest shaking to a distant location even though the earthquake has already started. Detection and communication can travel ahead of the damaging waves, but nearby places may receive little or no warning.

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