The diagram shows the positions of the sun, moon and Earth during spring tides, when the high tides are at their highest and low tides at their lowest. What is it about these positions that causes these high and low tides?
When the moon is full or new, the gravitational pull of the moon and sun are combined. At these times, the high tides are very high and the low tides are very low. This is known as a spring high tide.
