How Coastal Processes Result in Coastal Erosion, Submersion, and Saltwater Intrusion

Summary

This educational video delves into coastal processes, focusing on erosion, submersion, and saltwater intrusion. It explains how coastal areas, transition zones between land and sea, are shaped by natural forces like tides, waves, and currents, as well as human activities. The video outlines key processes such as abrasion, attrition, hydraulic action, and corrosion that contribute to coastal erosion. It also discusses sediment movement and coastal deposition, highlighting how waves' energy loss leads to sediment accumulation, forming new landforms. The video serves as a comprehensive guide to understanding the dynamic nature of coastlines.

Takeaways

• 🌊 **Coastal Erosion**: The process where the land is worn away by the sea, primarily through destructive waves.
• 🏖️ **Coastal Features**: Coasts have diverse features such as caves, cliffs, pitches, and mad flats, shaped by external forces like tides, waves, and currents.
• ⛰️ **Mechanical Erosion (Attrition)**: Waves cause rocks and pebbles to collide, leading to the breaking down of materials.
• 💧 **Hydraulic Action**: The force of waves drives water into cliff cracks, causing pressure that can lead to rock fragmentation.
• 🌪️ **Abrasion**: Similar to sandpaper, breaking waves with sand and debris smash against cliffs, causing erosion.
• 🌄 **Creation**: A process where waves hurl beach materials at cliffs, causing erosion.
• 🌬️ **Corrosion/Solution**: The dissolution of rocks, especially limestone, by weak acids like carbonic acid formed from dissolved carbon dioxide.
• 🏝️ **Human Impact**: Humans have built coastal features like harbors, defenses, and artificial islands, impacting natural coastal processes.
• 🌊 **Longshore Transport**: Sediments move along the coast due to waves approaching at an angle to the shoreline.
• 🏖️ **Coastal Deposition**: Occurs when waves lose energy and can no longer carry sediments, leading to sediment deposition, particularly in shallow or sheltered areas.

Q & A

What are the three dominant coastal processes discussed in the video?

The three dominant coastal processes discussed in the video are coastal erosion, the movement of sediments along the coast, and coastal deposition.

What is coastal erosion, and how does it occur?

Coastal erosion is the wearing away of the land by sea, caused by destructive waves. It occurs through processes such as creation, abrasion, attrition, hydraulic action, and corrosion or solution.

What is the 'sandpaper effect' mentioned in the video?

The 'sandpaper effect' refers to abrasion, where breaking waves containing sand and large fragments smash along the cliff and wear it away.

How is attrition different from abrasion in the context of coastal erosion?

Attrition differs from abrasion in that it involves waves causing rocks and pebbles to bump against each other, leading to the eventual breaking of the materials, whereas abrasion involves two surfaces rubbing against each other.

What is hydraulic action, and how does it contribute to coastal erosion?

Hydraulic action is the effect of waves hitting cliff faces, forcing air into cracks in rocks. This creates pressure that can cause the rock to crack, break, and splinter, contributing to coastal erosion.

Can you explain the process of corrosion or solution in coastal erosion?

Corrosion or solution in coastal erosion involves the dissolution of rocks, such as limestone, by weak acids like carbonic acid, which forms when carbon dioxide dissolves in water.

What is the movement of sediments along the coast, and how does it happen?

The movement of sediments along the coast, also known as longshore transport or littoral drift, occurs when waves crash on the shore, pushing sediment up the beach and pulling it back down as the water recedes.

What is coastal deposition, and under what conditions does it occur?

Coastal deposition is the process where waves, having lost their capacity to transport sediments, drop or deposit their sediment load. This happens in areas of shallow water, sheltered areas like bays, when there is little or no wind, and a sufficient supply of sediments.

How does the swash and backwash of waves affect coastal deposition?

Coastal deposition occurs when the swash (waves rushing inland) is stronger than the backwash (waves rushing back to the sea), indicating that the waves are losing kinetic energy needed to transport sediments.

What are some human-built coastal features mentioned in the video?

Some human-built coastal features mentioned in the video include harbors, coastal defenses, and artificial islands.

What effect does coastal erosion have on infrastructure along the coast?

Coastal erosion can lead to the destruction of houses and other infrastructures along the coast, as well as the steepening of the coastal area.