Spring tides

Tides of large range which occur approximately twice a month, when the moon and sun are in phase around times of new or full moon.

 

Figure: (A) View looking down upon the Earth from the north pole when the Earth, Moon and Sun are aligned (during full or new moon) – the equilibrium tidal bulges associated with the Moon and Sun are in phase and combine to create spring tides; (B) a tidal curve over a 15 day period using periods of spring tides.