tides

Write the following questions in your notebook and answer them in complete sentences. 1. What is high tide? 2. What is low tide? 3. What is a daily tide range? 4. What typical pattern of daily tides occurs at most coastal locations on Earth with every cycle of Earth’s rotation? 5. What fundamental force could possibly be associated with daily tides?

Tides are caused by the pull of the Moon and Sun on Earth’s bodies of water.

The fundamental force of gravity acts on all matter, including water.

Gravitational forces of the Earth, Sun, and Moon system create tidal bulges with large bodies of water on Earth.

When Earth turns on its axis, coastlines rotate in and out of tidal bulges causing daily high and low tides.

The water level along the coast rises and falls in a regular pattern as the Moon revolves around Earth and as Earth revolves around the Sun. During the day the sea level is rising or falling several times: 1. The sea level rises until a high tide occurs. 2. The sea level falls until a low tide occurs. 3. Back to number 1. This cycle can happen once or twice a day depending on the location of the Moon.

During spring tides, the high tides are higher than normal and low tides are lower.

During neap tides, the high tides are not as high as normal and the lower tides are not as low as normal.

Tide Activity

A limitation of this model is that it looks as if the Moon holds water in place while the solid Earth spins on its axis. What is really happening? What are other limitations of this model?

Times for daily high tides and low tides change by a few minutes each day for coastline communities. What causes the time of daily tides to change as shown by your model? Why are we able to predict tides?

Why does the Moon have a greater effect on Earth’s tides than the more massive Sun?

When the formation of the Earth-Sun-Moon system causes linearly aligned gravitational forces, daily high tides are higher and low tides are lower than usual. Daily tidal ranges (the differences between water levels of high and low tides) are the greatest during spring tides, how often do they occur during each lunar cycle?

When the formation of the Earth-Sun-Moon system causes opposing gravitational forces, low tides are not as low as usual and high tides are not as high as usual. Daily tidal ranges (the difference between water levels of high and low tides) are the least during neap tides, how often do they occur during each lunar cycle?