World Geography 3200/3202

OutcomesIn this section you will: 1.5.1 Define the term spit. (k)1.5.2 Define the terms sea cave, sea arch,

and stack. (k)1.5.3 Explain how sea caves, sea arches and

stacks are formed. (a)1.5.4 Analyze the processes that result in the

“straightening out” of an irregular coastline. (a)

Water/Wave Erosion ConceptsThree Weathering Terms 1. Hydraulic pressure: The pounding force of

water/waves

2. Corrosion: Minerals such as calcium carbonate and limestone dissolve in the water

3. Abrasion: rock and sand particles suspended in the water bump, grind, scrape and gouge surfaces the water hits.

Water/Wave Erosion Concepts Longshore Drift Terms

1. Headlands: the protrusions of land that extend the farthest out into wave action.

2. Longshore drift: refers to the fact that dominant waves have enough energy to carry silt/sand from headlands along the shore where it is later deposited.

3. Wave Refraction: waves bending around headlands as they hit the shallow water by shore

Straightening an Irregular Submerging CoastlineIrregular submerging coastlines have

headlands that protrude out from the shore line.

The erosion of the headland can deposit silt in the bay which forms a bay beach as it tends to reduce the irregularity of the coastline.

The headland is reduced due to erosion and the bay is being filled by deposition.

Straightening an Irregular Submerging CoastlineLongshore drift results in some sand being

deposited parallel to the shore but connected to the headland. These silt deposits are known as spits.

Longshore drift and deposition can continue to the point that the spit closes off the mouth of the bay. This extensive deposit is known as a bay bar. As you can see it tremendously reduces the irregularity in the coastline.

Continued erosion and deposition can straighten a coastline over a long period of time.

Straightening an Irregular Submerging CoastlineSketch the following diagrams to help with

your understanding of the steps for straightening an irregular coastline

Assigned Readings"Wave Movement and Direction" on pages

41-42;

"Effects of Wave erosion and Deposition" on pages 42-44.

Case StudyAssigned Readings"CASE STUDY the Curonian Spit" on pages

45-46.

Assigned ActivitiesComplete Question #17 on page 46.