Spatial Association: When 2 features are generally found in close proximity to eachother. Eg. Coasts and Populations
Importance of Australian coasts:
1. Economic:
Europeans settles results in centre of economic life
Ports – exporting goods, vital for making money
Industry – fishing
Tourism – tourists come to see and experience beaches
2. Social
Relax, cool off in sumer
‘Place to be seen’ (surf culture)
Scenery
Family environment
3. Physical
Coast is appealing
Coral reefs eg. Great barrier reef contain colourful coral and fish
Features influencing Australia’s Population Distribution:
1. Temperature – much cooler and more bearable temperatures on the coast than in the interior of the continent.
2. Land Productivity – coastal land is more fertile and is good for intensive agriculture.
Intensive agriculture – small scale farming on small areas of land with high crop yield
Extensive agriculture – large scale farming on large areas of land with low crop yield
3. History – these were the first regions settled by Europeans
4. Employment – more employment opportunities eg. Manufacturing, fishing and ports
The formation of coastlines:
Constantly changing. Some retreating backwards and others advancing seawards.
Tectonic forces – internals forces that create landforms and coastlines.
Gradational processes – external forces that wear down or break up or level coastal landforms. EROSION OR DEPOSITION.
TECTONIC FORCES:
Cause movement on the surface of the earth. Uplift land causing mountains and valleys. Cause continents to move away, collide or slide against each other.
Structure of the Earth:
Oceanic crust 11-16km
Continental crust 100km
Core made of iron and nickel and 6000 degrees
Outer core molten rock
Inner core solid
Convection currents:
Uneven heating in the mantle means that the upper mantle is cooler than the lower mantle
Hot molten that is being heated by the core rises towards the surface of the mantle where heat is transferred to the surface (through volcanos and thermal springs etc.) as the molten rock at the top cools it begins to sink back towards the bottom of the mantle where it will be heated again. This process causes the circular flow of magma in the mantle and causes plates to move on the crust.
Ridges:
Diverging plate boundary – constructive
Oceanic-oceanic boundary
Process:
1. Convection currents cause plates to move away from each other
2. As sea floor spreads molten rock rises and cools on the surface creating new land
3. Volcanic island is formed
Example: Iceland
Trenches
Converging plate boundary – destructive
Oceanic-continental boundary
Process:
1. Plates move towards each other due to convection currents
2. Heavier oceanic plate is forced under the lighter continental plate (SUBDUCTION)
3. Creates v-shaped valleys
4. Continental plate compressed upwards creating fold mountains
5. Oceanic plate subducts and melt forming a magma chamber
6. Built up pressure needs to be released – volcano
Example: Nazca and south American plates creates the Andes
Shatterbelt
Shatterbelt is a series of Block Mountains (horsts) and rift valleys (grasens). Block Mountains form the Flinders and Mount Lofty Ranges and the rift valleys form the gulfs Spencer and St Vincent.
Formed by tectonic forces. Tectonic pressure within the Indo-Australian plate due to the convection currents has caused faulting (cracks) in a north-south orientation . 450 million years ago the major uplift and sinking occurred. The uplift has produced Block Mountains (Mount Lofty and Flinders ranges) as well as the up land blocks, one being the eyre Peninsula Upland. The Rift Valleys are the Spencer Gulf and the St Vincent Gulf. Erosion has occurred along the coast from where the wave action and wind in the gulfs onto the edge of the upland areas.
GRADATIONAL FORCES:
Coastal landscapes:
Australia has sandy coastlines (beaches, bays) and rocky shores (islands cliffs)
