When do spring tides occur?

• A. The Moon is new
• B. Sun and Moon are in alignment
• C. The Sun is at zenith
• D. Sun and Moon are perpendicular

Answer: (B)

The main idea is that tides are created by gravity from the Moon and the Sun, and their effects add strongest when those pulls line up. When the Moon, the Sun, and the Earth are in a straight line, their gravitational forces reinforce each other, producing spring tides with higher high tides and lower low tides. This alignment happens during new moon and full moon phases, when the Sun and Moon are on the same side or opposite sides of the Earth. Conversely, when the Sun and Moon are at right angles relative to Earth, their gravity partially cancels, creating neap tides with less extreme tides. So spring tides occur when the Sun and Moon are in alignment.