5.1 TIDAL DEFINITIONS & IMPORTANCE

Question 1

What are tides?

Answer 1

The regular and predictable rise and fall of the sea caused by the gravitational attraction and rotation of the Sun, moon and Earth system.

Normally used to refer to the vertical change in sea level.

Question 2

What are tidal currents?

Answer 2

Used for the horizontal movement of water.

Question 3

What is sea level?

Answer 3

Relates to the vertical change in height of sea surface which occurs over all time and space scales from many different mechanisms

• including waves, seiches, storm surges & tsunamis
• with tides being the most predictable and dominant component of sea level variability in many parts of the world’s oceans and coasts.

Question 4

Why are tides important?

Answer 4

1. Navigation
2. Renewable energy
3. Coastal flooding
4. Coastal morphology
5. Coastal erosion
6. Estuarine flushing
7. Biology
8. Intertidal biology
9. Habitat creation