How is a Marine Terrace Related to a Wave-Cut Platform?
Marine terraces and wave-cut platforms are two types of coastal landforms that are intimately connected, yet distinct from each other. In this article, we will explore the relationship between these two features and examine their characteristics, formation mechanisms, and significance in coastal geomorphology.
What are Marine Terraces and Wave-Cut Platforms?
Before delving into the relationship between these two landforms, it is essential to understand what they are.
Marine Terraces
Marine terraces are flat or gently sloping coastal landforms that are formed when a coastline is uplifted or submerged due to changes in sea level. During times of high sea level, the coastline is forced inland, and a wave-cut platform is created. When the sea level drops, the coastline readvances, and the platform is left behind, forming a marine terrace.
Wave-Cut Platforms
A wave-cut platform, on the other hand, is a flat or gently sloping coastal surface that is formed by the erosion of the cliff or rocky shoreline by waves. The platform is formed when the waves cut away the base of the cliff or shoreline, creating a flat or gently sloping surface.
Relationship between Marine Terraces and Wave-Cut Platforms
Now that we have a basic understanding of these two landforms, let’s explore the relationship between them.
- Direct Relationship: A wave-cut platform is often the precursor to a marine terrace. When a coastline is uplifted or submerged, the wave-cut platform is created, and then the platform is left behind, forming a marine terrace.
- Indirect Relationship: Marine terraces can also be formed from wave-cut platforms through other mechanisms, such as changes in sediment supply or erosion rates. For example, if sediment supply increases, the platform may be covered, and a new wave-cut platform may form.
- Interdependence: The formation of marine terraces and wave-cut platforms is interdependent. Changes in sea level, sediment supply, and erosion rates all influence the formation of both landforms.
Formation Mechanisms
The formation of marine terraces and wave-cut platforms is a complex process that involves a combination of geological and coastal processes. Here are the key formation mechanisms:
Marine Terraces
- Uplift or Subsidence: Changes in sea level cause the coastline to move inland or seaward, forming a marine terrace.
- Sediment Deposition: Sediment supply can alter the shape and height of the marine terrace.
- Erosion: Erosion of the cliff or rocky shoreline can create a wave-cut platform, which then forms a marine terrace.
Wave-Cut Platforms
- Wave Action: The erosion of the cliff or rocky shoreline by waves creates a wave-cut platform.
- Changes in Sediment Supply: Changes in sediment supply can alter the shape and extent of the wave-cut platform.
- Tectonic Activity: Tectonic activity, such as uplift or subsidence, can create a wave-cut platform by changing the shape and height of the coastline.
Significance in Coastal Geomorphology
Marine terraces and wave-cut platforms are important features in coastal geomorphology because they:
- Reveal Past Changes in Sea Level: Marine terraces and wave-cut platforms can provide valuable information about past changes in sea level and coastal processes.
- Influence Coastal Processes: The shape and height of these landforms can influence coastal processes, such as sediment supply and erosion.
- Affect Human Settlements: The presence of marine terraces and wave-cut platforms can affect human settlements, such as the placement of coastal structures and infrastructure.
Comparison Table
Here is a comparison table highlighting the key differences between marine terraces and wave-cut platforms:
Feature | Marine Terraces | Wave-Cut Platforms |
---|---|---|
Formation | Uplift or subsidence, sediment deposition, erosion | Wave action, changes in sediment supply, tectonic activity |
Shape | Flat or gently sloping | Flat or gently sloping |
Height | Varies | Varies |
Relationship to Coastline | Formed as the coastline is uplifted or submerged | Formed as the coastline is eroded |
Conclusion
In conclusion, marine terraces and wave-cut platforms are intimately connected landforms that are formed through a combination of geological and coastal processes. Understanding the relationship between these two landforms is crucial for understanding coastal geomorphology and its significance in shaping our coastline.