High & Low energy coasts
High and low energy coastlines are classified by the strength of their wave action, which determines whether erosion or deposition dominates. High-energy coasts have powerful waves, leading to erosion exceeding deposition and forming features like cliffs and headlands. Low-energy coasts have less powerful waves, where deposition is greater than erosion, creating features like beaches and spits.
High-energy coastlines
Wave energy: High, powerful waves for a significant part of the year.
Fetch: Often associated with a long fetch, which allows winds to create large, powerful waves.
Dominant process: Erosion exceeds deposition.
Typical landforms: Cliffs, headlands, wave-cut platforms, and sea caves.
Coastal Processes including change over time
Coastal processes are driven by forces such as waves, tides, and weather, and involve the key mechanisms of erosion, transportation, and deposition. Over time, these processes, influenced by factors like geology and sea-level changes, constantly reshape the coastline.
Impacts of coastal erosion
Holderness coast
(case study)
Coastal erosion leads to the loss of land, homes, and infrastructure, and can damage ecosystems and historic sites. It also causes economic problems, such as decreased property values, reduced tourism, and a lack of investment in vulnerable areas. Environmentally, it can lead to habitat loss for species like mudskippers and reduce biodiversity.
Sediment transport
Sediment transport is the movement of solid particles, such as sand, silt, and clay, by natural forces like water or wind, which can be influenced by gravity, waves, and tides. This process happens through several methods, including traction (rolling along the bottom), saltation (bouncing), suspension (floating in the water), and dissolution. It is a fundamental process in coastal and river systems that shapes the landscape and can impact ecosystems and water supplies.
Influence of geology on coasts
Geology influences coastlines through the rock type, rock structure, and porosity, which determine erosion rates and the resulting landforms
Hard rocks:
Materials like granite and chalk are more resistant to erosion and weather slowly, leading to steeper cliffs and rocky coastlines.
Soft rocks:
Materials like clay and shale erode quickly, leading to low-lying coastlines and features like beaches and bays.
Porosity:
Sedimentary rocks, with their pores, allow water to infiltrate, increasing erosion rates, while less porous rocks like igneous rocks erode more slowly.
