The correct option is 1 and 3 only.
Explanation
Tides are the periodic rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon and the Sun, and the rotation of the Earth. Spring tides represent the period of the highest tidal range.
- Statement 1 is Correct: Spring tides occur when the Sun, the Moon, and the Earth are aligned in a straight line. This linear configuration is technically known as syzygy. In this alignment, the gravitational pull of the Sun is added to the gravitational pull of the Moon.
- Statement 2 is Incorrect: Spring tides occur twice a lunar month, not once. They take place during the full moon phase (when the Earth is between the Sun and the Moon) and the new moon phase (when the Moon is between the Sun and the Earth).
- Statement 3 is Correct: Because the gravitational forces of the Sun and the Moon reinforce each other during syzygy, the water is pulled more strongly. This results in high tides that are higher than average and low tides that are lower than average. Consequently, the tidal range (the vertical difference between high tide and low tide) is greater than normal.
Key Takeaway: Spring tides occur twice a month during the new moon and full moon phases when the Sun, Moon, and Earth are in syzygy, resulting in the maximum tidal range due to combined gravitational forces.