Spring Tides

Spring Tides

Middle School

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Learning Objectives

• Define a spring tide and describe its main characteristics.

• Explain how the alignment of the Sun, Earth, and Moon causes spring tides.

• Identify the two moon phases during which spring tides occur.

• Understand why spring tides result in higher high tides and lower low tides.

Key Vocabulary

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Spring Tide

A tide with the greatest difference between high and low points that occurs during specific lunar phases.

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Tidal Range

The vertical difference between the high tide and the succeeding low tide, which is greatest during spring tides.

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Gravitational Pull

The force of attraction exerted by the Sun and Moon that causes the tides on Earth.

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New Moon

The lunar phase when the Moon is directly between the Earth and Sun, creating alignment for spring tides.

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Full Moon

The lunar phase when Earth is between the Sun and Moon, also creating alignment for spring tides.

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What Are Spring Tides?

• A spring tide has the greatest difference between high and low tide.

• This creates a greater tidal range with very high and low tides.

• They are caused by the combined gravitational pulls of the Sun and Moon.

• This happens when the Sun, the Moon, and Earth are in alignment.

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Multiple Choice

What is the primary cause of the greater tidal range during a spring tide?

• The Earth being closer to the Sun.

• The alignment of the Earth and Moon at a right angle to the Sun.

• A decrease in the Moon's gravitational pull.

• The additive gravitational pulls of the Sun and Moon.

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When Do Spring Tides Occur?

New Moon Phase

• Spring tides happen when the Earth, the Moon, and the Sun align.

• During a new moon, the Moon is between the Sun and Earth.

• This alignment creates a powerful combined gravitational pull on the oceans.

Full Moon Phase

• The Earth, Moon, and Sun are also in a straight line here.

• During a full moon, Earth is between the Sun and the Moon.

• This alignment also causes spring tides, roughly 14 days after the new moon.

Multiple Choice

Spring tides occur twice a month, in conjunction with which two celestial events?

• When the Moon's gravitational pull is at its weakest.

• During the first and third quarter moon phases.

• Whenever there is a solar or lunar eclipse.

• When the Earth, Moon, and Sun are lined up during a new and full moon.

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Common Misconceptions About Spring Tides

Misconception	Correction
Spring tides only happen during the spring season.	They are named for 'springing forth' and occur all year.
Spring tides are caused only by the Moon.	They result from the combined gravity of the Sun and Moon.
The water level only rises during a spring tide.	They cause higher high tides and lower low tides.

Multiple Choice

Why is the tidal range, the difference between high and low tide, greatest during a spring tide?

• Because the Moon's orbit brings it closer to Earth, increasing its gravity.

• Because ocean currents are stronger during these specific times of the month.

• Because the Earth moves closer to the Sun during the new and full moon.

• Because the Sun and Moon's gravitational forces are combined and pull in the same direction.

Multiple Choice

If you observe a full moon tonight, what effect would you expect it to have on the tides?

• There will be lower than normal high tides and higher than normal low tides.

• The tides will stop changing for 24 hours.

• Tides will be average, with no noticeable difference.

• It will lead to a spring tide, with higher high tides and lower low tides.

Multiple Choice

A coastal city is planning to build a seawall. Why is it critical for the engineers to consider the timing of spring tides?

• Because the exceptionally high tides during spring tides represent the maximum water level the wall must withstand.

• Because the lower low tides during spring tides make it easier to build the foundation.

• Because the Sun's gravity is weaker during spring tides, making construction safer.

• Because spring tides only occur in the spring, which is the main construction season.

Multiple Choice

Analyze the effect on tides if the Moon's gravitational pull remained constant, but the Sun no longer exerted any gravitational force on Earth's oceans. How would this change the phenomenon of tides?

• The difference between spring tides and neap tides would disappear; all tides would be the same.

• High and low tides would still occur, but the extreme variations of spring tides would not happen.

• Tides would cease to exist altogether.

• Tides would become much stronger because there would be no competing gravity from the Sun.

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Summary

• Spring tides feature the greatest difference between high and low tide levels.

• They are caused by the Sun and Moon’s combined gravitational forces.

• This alignment results in higher high tides and lower low tides.

• Spring tides occur twice a month, during new and full moons.

Poll

On a scale of 1-4, how confident are you about the concepts covered in today's review?

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