What Causes Tides?
Tides are caused primarily by the gravitational pull of the Moon (and to a lesser extent the Sun) on the Earth's oceans. As the Earth rotates, bulges of water follow the Moon, creating the rise and fall of sea level we call tides.
Most places around the UK experience semi-diurnal tides — two high waters and two low waters in roughly 24 hours and 50 minutes. The extra 50 minutes is because the Moon orbits the Earth, so high water occurs about 50 minutes later each day.
Key Points
- Tides are caused by the gravitational pull of the Moon and Sun
- UK has semi-diurnal tides — two highs and two lows per ~25 hours
- High water occurs ~50 minutes later each day