Back to topics

Why does the distance between high and low tide change?

A coastline’s high and low water levels do not always have the same separation. The changing positions of the Sun, Moon, and Earth contribute to spring and neap tides. Local coastlines and basins add complexity, so the basic astronomical pattern does not by itself predict a tide at a particular beach.

5–7 min

Questions you could explore

  • What does “spring” mean in a spring tide?
  • How is tidal range different from the time of high tide?

Start reading

Ready to try your ideas aloud?

Your topic carries over. Record up to 2½ minutes, depending on your plan.

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.

Why does the distance between high and low tide change? | Speech Topic | speaking.app