Junior Cycle Geography CYCLONE 11.4 Landforms of Sea Deposition
Feature: Beach A beach is a gently sloping area of sand, shingle (pebbles) or stones that is found between the high and low tide levels. It is formed by the swash and backwash movements of the waves.
How a Beach Forms
1. When waves break, they lose their energy and drop the load they were carrying. The swash carries this material up the shore and deposits it.
2. In constructive waves, the backwash is weaker than the swash, so it is unable to carry all of the deposited material back out.
3. The heaviest material is deposited first, and the finer material is carried closer to the shoreline. 4. Over time, this material builds up to form a beach.
5. During storms, the waves are stronger and are able to carry heavier material further up the shoreline to the high-tide mark. This material is then deposited and creates a storm beach.
Examples: Beaches can be seen at Tramore, Co. Waterford (see the photo below), and Donabate, Co. Dublin.
Storm beach (rocks and
bigger stones)
Sand dunes
Marram grass
Fine sand
Processes at work Longshore drift Deposition Swash Backwash
Waves break
High tide mark
Low tide mark
Coarser material (shingle)
7. A beach
Managing information and thinking
Look at the photo of the beach. Can you identify some of the areas of the beach? Can you point out the sand dunes, marram grass, etc. by using figure 7 to help you?