Whats expected for todayBy 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
Textbook p. 144 Headlands and baysHeadlands 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.
Textbook p. 144 Headlands and baysMore resistance rock → the faster/slower it takes for waves to erode itLess resistant rock → the faster/slower it takes for waves to erode it
1.3 FormationWave 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. 
1.3 Formationdifferent 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 specificsGranite and basalt are examples of more resistant rock.
Textbook p. 144 1.1 Some specificsChalk, sandstone, and shale examples of less resistant rocks.
Textbook p. 144 1.1 Some specificsWhat 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 refractionWave refraction refers to the bending of waves because of differences in wave speeds.
Textbook p. 145 1.2 Wave refractionWaves 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 refractionWave 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 Less resistant rock Bay At a coast where resistant rocks alternate More with less resistant resistant rock rocks, Headland the less resistant rocks are eroded at a faster rate than the resistant rocks.More resistant rock Headland Figure 1: Formation of headlands and bays
Textbook p. 1441.3 Formation The different rates of erosion along the coas produces an uneven coastline.
Textbook p. 1441.3 Formation The less resistant rocks curve inwards, forming bays, while the more resistant rocks protrude from the coastline, forming headlands.
HomeworkPart 1 Complete asterisked (*) question under 1.2 Some specificsPart 2 Read textbook pages 146-148 for tomorrows lesson on beaches, spits and tombolos.
Looking back and ahead...1. Coastal processes 2. Coastal landformsErosion ✔ Cliff & shore platform ✔Deposition ✔ Headland and bay ✔Longshore drift ✔ Beach Spit Tombolo 3. Coastal engineering
Whats expected for todayBy 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
BeachA 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 thesediment, thesteeper the beachgradientPebble Beach,California
The finer thesediment, thegentler the beachgradientMoonlight Cove,California