Neap tides occur during which Moon phases?

Neap tides occur during which Moon phases?

• A. First Quarter and Third Quarter
• B. New Moon and Full Moon
• C. Full Moon and Third Quarter
• D. First Quarter and Full Moon

Answer: (A)

Neap tides happen when the Sun and Moon pull on Earth’s oceans in perpendicular directions. This occurs when the Moon is at its first or third quarter—half illuminated and about 90 degrees away from the Sun in the sky. Because the solar and lunar gravitational effects act at right angles, they partially cancel each other, so the high tides aren’t very high and the low tides aren’t very low—the tidal range is reduced. In contrast, during new Moon or full Moon the Sun and Moon line up, and their gravitational forces reinforce each other, producing stronger tides (spring tides). So the phases associated with neap tides are first quarter and third quarter.

Neap tides happen when the Sun and Moon pull on Earth’s oceans in perpendicular directions. This occurs when the Moon is at its first or third quarter—half illuminated and about 90 degrees away from the Sun in the sky. Because the solar and lunar gravitational effects act at right angles, they partially cancel each other, so the high tides aren’t very high and the low tides aren’t very low—the tidal range is reduced.

In contrast, during new Moon or full Moon the Sun and Moon line up, and their gravitational forces reinforce each other, producing stronger tides (spring tides). So the phases associated with neap tides are first quarter and third quarter.