Diurnal Tidal Pattern
A diurnal tidal pattern has a single high and low tide each lunar day. These tides are common in shallow inland seas such as the Gulf of Mexico and along the coast of Southeast Asia. Diurnal tides have a tidal period of 24 hours 50 minutes.
In short we can say: Diurnal
- One high tide/one low tide per day
- Rarest
Semidiurnal Tidal Pattern
A semidiurnal tidal pattern has two high tides and two low tides each lunar day. The heights of successive high tides and successive low tides are approximately the same.11 Semidiurnal tides are common along the Atlantic Coast of the United States. The tidal period is 12 hours 25 minutes.
In short we can say: Semidiurnal
- Two high tides/two low tides per day
- Tidal range about same
Mixed Tidal Pattern
A mixed tidal pattern may have characteristics of both diurnal and semidiurnal tides. Successive high tides and/or low tides will have significantly different heights, a condition called diurnal inequality. Mixed tides commonly have a tidal period of 12 hours 25 minutes, but they may also exhibit diurnal periods. Mixed tides are the most common type in the world, including along the Pacific Coast of North America.
In short we can say: Mixed
- Two high tides/two low tides per day
- Tidal range different
- Most common
Note :
Most areas on Earth should experience two high tides and two low tides of unequal heights during a lunar day. In practice, however, the various depths, sizes, and shapes of ocean basins modify tides so they exhibit three different patterns in different parts of the world.
