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7 Feb 2026

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2 pages

Understanding Coastal Processes

lill

@lourestmainx

Ever wondered why some coastlines crumble away whilst others build... Show more

Destructive and Constructive Waves

When wind blows across the sea, it creates waves that can either build up or tear down coastlines. Storm surges happen when strong winds literally push seawater towards the shore, causing temporary but dramatic rises in sea level.

Destructive waves are the bullies of the coastline - they're high, steep, and hit frequently. Their backwash (water flowing back to sea) is stronger than their swash (water rushing up the beach), so they drag material away from the coast. Think of them as nature's demolition crew.

Constructive waves are the complete opposite - they're gentle giants that are long, low, and less frequent. Their swash overpowers the backwash, so they actually deposit sand and pebbles, building up beaches rather than destroying them.

Waves use three main methods to erode coastlines: hydraulic action (waves crash and compress air in rock cracks), abrasion (particles scrape against rocks like sandpaper), and attrition (particles bash into each other and break down).

💡 Quick Tip: Remember that fetch (the distance wind travels over water) directly affects wave power - longer fetch means more powerful waves!

Mass Movement

Gravity never takes a day off, and when it comes to coastal erosion, mass movement can cause cliffs to collapse dramatically in a single event. This happens when the downward pull of gravity becomes stronger than whatever's holding the slope together.

Water acts like a lubricant in coastal materials, making mass movement much more likely after heavy rainfall. When large chunks of cliff do shift, they often leave behind a scarp - essentially a steep scar on the landscape.

There are three main types of mass movement you need to know. Slides occur when material moves in a straight line along a flat surface. Slumps happen when material rotates along a curved surface, creating that distinctive stepped appearance. Rockfalls are exactly what they sound like - rocks breaking away and tumbling down.

Mass movement causes coasts to retreat rapidly, sometimes losing metres of land overnight. This is why coastal management is so crucial for protecting homes and infrastructure near cliff edges.

💡 Remember: Mass movement is gravity-driven, but water content is often the trigger that makes it actually happen!

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Biology

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7 Feb 2026

•

2 pages

Understanding Coastal Processes

lill

@lourestmainx

Ever wondered why some coastlines crumble away whilst others build up with sand and pebbles? It's all down to the power of waves and gravity working together to constantly reshape our shores.

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Destructive and Constructive Waves

💡 Quick Tip: Remember that fetch (the distance wind travels over water) directly affects wave power - longer fetch means more powerful waves!

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Mass Movement

Mass movement causes coasts to retreat rapidly, sometimes losing metres of land overnight. This is why coastal management is so crucial for protecting homes and infrastructure near cliff edges.

💡 Remember: Mass movement is gravity-driven, but water content is often the trigger that makes it actually happen!