A beach berm is a distinctive feature of many beaches, forming a step or terrace above the normal high tide level.
Understanding the Beach Berm
Based on the provided reference, a berm is described as a terrace of a beach that has formed in the backshore, above the water level at high tide. This means you'll find it inland from the typical wave wash, elevated compared to the wet sand area.
Here are the key characteristics of a beach berm based on this description:
- Location: Formed in the backshore, which is the part of the beach above the high-tide line, only usually affected by waves during storms or very high tides.
- Elevation: It sits above the water level at high tide.
- Typical Sand Type: Berms are commonly found on beaches that have fairly coarse sand.
- Formation: They are the result of the deposition of material by low-energy waves.
Formation Process
Berms are built up by the action of waves. Specifically, they are formed by low-energy waves. These waves, often during calmer periods, carry sand and sediment up the beach. As the wave loses energy and recedes, it leaves behind the deposited material, particularly the coarser sand. Over time, this repetitive deposition builds up the elevated terrace known as a berm.
Key Features of a Beach Berm
| Feature | Description |
|---|---|
| Location | Backshore (above high tide) |
| Structure | Terrace or step |
| Formation | Deposition by low-energy waves |
| Sand Type | Commonly found with fairly coarse sand |
| Elevation | Above the water level at high tide |
Essentially, think of a berm as a natural embankment built by gentle waves dropping off sand high up on the beach. It's a clear indicator of how waves shape the coastline over time.
