1. Shoreline Processes and Features Outline
Forces Acting on the Shoreline
Wave Impact
Abrasion
Wave Refraction
Longshore Transport
Erosional Features
Wave-Cut Cliffs and Platforms
Sea Arches and Sea Stacks
Depositional Features
Spits, Bars, and Tombolos
Barrier Islands
Stabilizing the Shore
Protective Structures
Beach Nourishment

2. Forces that act on the Shoreline
(1) Wave Impact and (2) Abrasion
Caused by
Sand/rocks + energy
Caused by
water + energy

3. Forces that act on the Shoreline
Waves usually approach the shore at a slight angle. Wave refraction causes wave’s path to bend and hit the shore straight on
Wave Refraction causes the headlands to receive more energy than beaches.
More Energy = More Erosion
This shoreline will slowly straighten

4. Forces that act on the Shoreline
Although waves are refracted most still reach the shore at a slight angle. This results in Longshore Transport
Longshore Transport
A near-shore current that moves fine suspended sand parallel to the coast

5. Erosional Features
These features are produced at areas of the shore that experience high energy impacts from waves

6. Wave-Cut Cliffs and Platforms
Erosional Features
Wave-Cut Cliffs and Platforms
Platform

7. Sea Arches and Sea Stacks
Erosional Features
Sea Arches and Sea Stacks

9. Depositional Features
Features produced by surface currents transporting sediments to areas that receive low impact wave energy
LOW ENERGY IMPACTS ALLOW SEDIMENTS TO BE DEPOSITED OUT OF THE LONGSHORE CURRENT

10. Depositional Features
Spits, Bars, and Tombolos

11. Depositional Features
Barrier Islands
Narrow sandbars parallel to, but separated from the coast
They may start off as sand spits that are later cut off from the mainland by erosion

12. Stabilizing the Shore
Large storms can erode shorelines far greater than average erosion rates. This can effect the natural evolution of the coast, wildlife, and cause property damage
This is why large sums of money are spent every year to prevent coastal erosion

13. Groins, breakwaters, and seawalls protect the coast from erosion
They may be doing more harm than good and they need to be maintained
Stabilizing the Shore
Groins, breakwaters, and seawalls protect the coast from erosion
Groins
seawall
Breakwaters

14. Stabilizing the Shore
Beach Nourishment is the addition of sand to beaches and is an alternative to protective structures
Drawbacks: It is expensive to move huge volumes of sand, transported sand “clouds” the water, alters and kills marine habitats, and removes sand from river systems that eventually would eventually make its way to the ocean