Australia’s land mass is almost equal to that of the United States and considerably larger than Europe. It is also the flattest continent. Its highest peak is only 2,228m. (France has 75 peaks higher than this). Australia is not at cool latitudes but cool climate regions exist due to the impact and influence of altitude and the surrounding oceans.
There are three main mountain ranges that impact the viticultural areas in Australia:
Darling Scarp in Western Australia:
This is the edge of the Yilgarn Craton and roses only to 400m.The best Western Australian regions are on this scarp - from Perth Hills down to Pemberton
Mount Lofty Ranges in South Australia:
This range makes viticulture possible in Adelaide Hills, Clare, Barossa and Eden Valleys
Great Dividing Range in Eastern Australia:
This is a major landform consisting of mountains and uplands. It is important to most of the GIs in New South Wales and Victoria. It brings height and acts as a barrier to tropical rain systems that come down the east coast effectively creating a rain shadow. The only major wine region on ’wrong’ side of range is the Hunter Valley which typically experiences mid-summer and harvest rain
Large parts of the north are tropical and the centre is too hot and dry. The areas most suited for fine wine production are in the SE and SW of the country. These areas have cool to warm Mediterranean climates.
Three main factors influencing the climate in these areas:
Weather patterns:
Prevailing cool weather patterns from the cold Southern Ocean moderate the warm northerly influence of the hot inland
Latitude:
Higher latitudes (further from equator) are cooler → southern Australia is much cooler than the north
Temperature decreases approximately 0.65°C for every 100 metres in altitude
Australia has been an individual land mass for over 100 million years and is the oldest and therefore most eroded continent with very old & complex soils. The oldest things on earth are found in Australia:
Zircon grains from Jack Hills in Western Australia are 4.4 billion years old (only 200 million years younger than the planet)
Cratons are predominantly granite outcrops and are the oldest formations of land on the planet. Australia has three cratons → 2 in Western Australia (Yilgarn and Pilbara cratons) and 1 in SA (Gawler craton). Wine is produced on edge of Yilgarn craton.
There are younger soils made up of sand and limestone and also many areas of volcanic origin. Tremendous soil variation from region to region and within the regions themselves