Geographers investigate enviroments Spacial Dimension= WHERE & WHY enviroments are there. Ecological Dimensions= How humands interact with enviroments. We investigate the Biophysical (Natural) and Built(Human) characteristics which make Australia unique
Location size and Shape Australia is the flattest and driest continent Only continent occupied by one country Australia gets its name from the Latin work "australis" meaning southern, used to refer to regions below equator.
Location Located in southern hemisphere between Indian and Pacific Oceans Latitudinal extent= 10o41'S and 43o39's Longitudinal extent= 113o09'E and 153o39'E Most Northerly point is Cape York Peninsula Most southerly point MAINLAND is South point on Wilsons Promotory Victoria Most Southerly point is Tasmanias South East Cape Most Westerly Point is steep point in WA Most East point is Cape Byron in NSW Spans almost 33o of latitude> Climate ranges from tropical to temperate Distance from eaast to west means it takes up 3 time zones Nearest neighbours are Papua New Guniea (North) and New Zealand (Southeast) No major landmasses or islands to the west Northwest are Indonesia and East Timor East lies small island countries e.g. Fiji, Vanautu and solomon islands,
Size Area of 7 682 300km2 6th largest only Russia Canada China and the USA and Brazil are larger 50% larger than Europe 20x Larger than Japan 32x larger than the UK\ Coastline of 36735 Km Long > difficult to secure against illegal imigrants and goods smuggling
Shape Compact in shape No significant bodies of water far inland > Contributes to dry conditions
Aboriginal Perspective Tells of a dreamtime when all things began Passed down by word of mouth over 1000s of years Explain how the world came about Providing- Basis for Spirituality- Rules to Live By-Sometimes a warning of Danger Not Everyone had same dreaming Strong link between land and people was common: It provided everything needed to survive and connected them with spiritual beings
Creation of Continent Ancestrel beings of the people emerged during dreamtime They come from Sky, Seas and ground Many could change their form from human plant or animal Journeying over Flat Land they sang into being both the landscape features and life forms When finished they dissapeared some back into sky whilst others merged into landforms such as Mountains, Gorges and rivers, still living today influenccing life
Map Dreaming Important record of the dreaming preserved in traditional paintings and decorated artifacts Paintings are like maps depicting landscapes and events of dreaming in aerial perspective. Use symbols in their artwork, so only those involved in its creation FULLY understand it. Some have many meanings
Geographical Origins of the Country Broad shape and distinctive lanforms have been influenced by earth movements wassociated with tectonic proccess. Crust is cracked in moving pieces called tectonic plates 9 large plates and a dozen smaller ones Larger plates contain continents and oceans Float on the dense rock below About 225 mil years ago the continent of Australia was part of Pangea, a supercontinentThis split into:-Godwana = South America, Africa, Antartica and Australia-Laurasia = North America Asia and Europe. Convection currents in the rocks cause plates to move slowly Theory of Continental drift
Mountain Building Tectonic processes also explains mountain building proccesses and volcanic activity When two plates collide mountain ranges are formed Fold Mountains are formed when one plate slides under the other Some rocks are forced down and some up making wave like forms Fault Mountains are formed when layers are fractures and one section moves down whilst one moves up. Australia's mountain ranges result from faulting and folding. e.g. Flinders Range Stirling Range and Great Dividing Range.
Volcanic Mountains Mountains can be formed by folding, faulting and volcanic activity Volcanic activity takes place around the margins of moving plates In the past huge lava plains covered considearable areas of Australia These occured as the continent drifted over hotspots in the mantle Hot spot volcanoes form in the middle of tectonic plates over source of magma. Hot spots stay still but tectonic plates keep moving 33 million years ago as Australia drifted northwards splitting from Antratrica, it passed over a large hotspot. Next 27 million years about 30 volcanoes errupted Over millions of years this hotspot process forms a chain This hotspot is now probably at bass strait Caldera of the tweed volcano is one of the biggest erosion calderas in the world. it moved over a hotspot 23 million years ago and errupted finishing 20 million years ago it was 2km high Ash and lava deposited over its outward slop forming a diamete of 100km After much erosion Mount Warning remains a remnant central plug and a hard range of mountains, McPherson, Tweed, Nightcap and Koonyum Mount Warning is about 1100 metres heigh and is so far east that it recieves sunlight first in Australia.
An Ancient Land The Earth is about 4600 million years old and the Australian continent is 4300 million years old Australia has undergone many changes e.g mountain changes and inland seas As mountain ranges eroded, sediments many kilometres thick were laid in vast areas. These sedimentary rocks were subjected to folding faulting and uplifting. Over time Weathering and erosion have worn these down again Erosion occurs quicker on softer rocks forming valleys and bays. Harder rocks become mountains hills and costal headlands
Lowest and Flatest Australia has no active volcanoes on its mainland and has little tectonic lift from below due to it being far from tectonic edges. This means its raised landforms are exposed longer to weathering than others. Because of this they are rounded and worn down Australia is the lowest and flattest of all continents. The topography results from erosion by a huge icecap about 190 mil years ago After melting, parts of continent subsided and were covered by sediments to form sedimentry basins e.g. Great Artesian Basin
Climate ChangeDuring last ice age temperatures were lower and water became trapped in ice sheets and glaciers. Sea level was 100 m lower New Guinea and Tasmania were attached to mainland Temperatures inland were temperate to subtropical> Great rivers lush vegetation much wildlife End of Ice age 15000 years ago sea levels rose Australia took on its shape and became isolated Low valleys were drowned making harbours e.g Sydney harbour As sea rose, valleys filled with alluvium forming typical costal lowland valleys High temps> change in climate> inland transformed into harsh dessert and semi-dessert
Land Bridges Aboriginal people descended from people migrating to Australia from south Asia Earliest large scale migration Began 50000 years ago during last ice age Walked across land bridge between New Guinea and Australia Islands closer together> Island Hopping Journey from Timor by canoe was difficult
Location Size and Shape
Origins from Aboriginal and Geographical Perspectives
Tectonic Processes and Volcanic Activity
Impacts of Changing Climates and Sea Levels