To predict the next date that the difference between low tide and high tide would be about 7 feet, we can look at the pattern of the tide types and the corresponding heights from the data provided:
- January 1: Full Moon, Spring Tide - 7.3 feet
- January 8: Half Moon, Neap Tide - 5.2 feet
- January 16: New Moon, Spring Tide - 7.4 feet
From the data:
- Spring tides (which occur during the full and new moon phases) tend to have a higher difference between low and high tides. Both Spring Tides in January (January 1 and January 16) show values above 7 feet (7.3 and 7.4 feet).
- Neap tides (which occur during the half moon phase) have a lower difference in tide heights, as evident with the January 8 reading of 5.2 feet.
Given that the next significant spring tide after January 16 would likely occur about 14 days later during the next full moon phase, we can look at the calendar:
- January 16 (New Moon) to January 31 (Full Moon) is approximately 15 days.
Thus, we can predict that the next occurrence of a spring tide, which could yield a height difference near 7 feet, will occur around January 31.
So, the closest date to that occurring would be January 31.