Sitges, Barcelona

What's expected for today By the end of this lesson, you should be able to: Explain how headlands and bays are formed with the help of well-labelled diagrams Draw clear diagrams in boxes with: Labels Title

v a r y ing r e s i s t a n c e to erosion. Textbook p. 144 Headlands and bays Headlands and bays form along a coast that is made up of bands of rock with v a r y ing r e s i s t a n c e to erosion. This means that, the rate at which a coast is eroded depends partly on rock resistance.

Less resistant rock → the faster/slower it takes for waves to erode it Textbook p. 144 Headlands and bays More resistance rock → the faster/slower it takes for waves to erode it Less resistant rock → the faster/slower it takes for waves to erode it

1.3 Formation Wave energy is concentrated at the headlands because the waves bend as they approach the protruding headlands. This is due to the waves slowing down as they reach the shallower waters in front of the headlands while other waves not affected by the headlands continue ahead at the same speed. [1]

1.3 Formation different rate of erosion of rocks along the coast produces an uneven coastline - less resistant rocks curve inwards, forming bays (Y) - while the more resistant rocks will protrude out from the coastline, forming headlands (X)

Textbook p. 144 1.1 Some specifics Granite and basalt are examples of more resistant rock.

Textbook p. 144 1.1 Some specifics Chalk, sandstone, and shale examples of less resistant rocks.

Textbook p. 144 1.1 Some specifics What are some of the places where headlands and bays can be found? This is Homework Part 1: due tomorrow (April 3, Tuesday).

Textbook p. 145 1.2 Wave refraction Wave refraction refers to the bending of waves because of differences in wave speeds.

Textbook p. 145 1.2 Wave refraction Waves bend and slow down as they approach the protruding headlands. Because they encounter friction with the increasingly shallow seabeds in front of these headlands

Textbook p. 145 1.2 Wave refraction Wave refraction causes headlands to be the focus of wave energy and thus the focus of erosion. Wave energy is weakened along the wider stretches in the bays, so waves deposit sediments at bays.

Textbook p. 144 1.3 Formation Bay Less resistant rock At a coast where resistant rocks alternate with less resistant rocks, the less resistant rocks are eroded at a faster rate than the resistant rocks. More resistant rock Headland More resistant rock Headland Figure 1: Formation of headlands and bays

Textbook p. 144 1.3 Formation The different rates of erosion along the coast produces an uneven coastline.

1.3 Formation The less resistant rocks curve inwards, forming bays, Textbook p. 144 1.3 Formation The less resistant rocks curve inwards, forming bays, while the more resistant rocks protrude from the coastline, forming headlands.

Homework Part 1 Complete asterisked (*) question under 1.2 Some specifics Part 2 Read textbook pages 146-148 for tomorrow's lesson on beaches, spits and tombolos.

Looking back and ahead... 1. Coastal processes Erosion ✔ Deposition ✔ Longshore drift ✔ 2. Coastal landforms Cliff & shore platform ✔ Headland and bay ✔ Beach Spit Tombolo 3. Coastal engineering

What's expected for today By the end of this lesson, you should be able to: Explain how a coastal SPIT is form with the help of well-labelled diagrams Predict what a spit would turn into if there is an offshore island nearby - TOMBOLO Draw clear diagrams in boxes with: Labels Title

Depositional Landforms In addition to shore platforms there are three other types of depositional landforms. Beach Tombolo Spit

Beach A beach is the result of constructive waves depositing material on the coast. Swash is stronger than backwash Waves have energy to bring material upshore but not back into the sea

The coarser the sediment, the steeper the beach gradient Pebble Beach, California

The finer the sediment, the gentler the beach gradient Moonlight Cove, California

Tombolo

Homework Complete Worksheet _____ in the Workbook.