Landscape

Lake Eyre is Australia’s largest salt lake and is named after drover turned explorer Edward John Eyre (1815-1901), who was the first European to sight the lake, in 1840. He called it ‘one vast, low dreary waste’. Almost 100 years later the explorer and geologist Cecil Thomas Madigan (1889-1947) travelled down its east side and called it, ‘a horrible travesty, and a vast white prostrate ghost of a lake’. The lake sits rather despondently on the edge of the barren Simpson Desert, one of the most remote and driest regions of the continent, with a yearly rainfall that rarely surpasses 120 millimetres. When dry it compromises an estimated 400 million tonnes of salt and is the lowest point below sea level in Australia. The salt crust during the long dry spells sometimes becomes so hard that it can support a vehicle. Sir Donald Campbell, the British speed ace, set the world land speed record there of 648.587 kilometres per hour in his Bluebird 2 on 17 July 1964. David Deague wishes he had been there.

Eyre National Park covers 228,000 hectares. This vast sheet of water and salt dates back more than 100 million years and was much larger than in the present. It was originally given the name Lake Dieri in honour of the local Aboriginal tribe that once lived by its shores. The Dieri people lived in harmony with the land and were hunters and gatherers. Lutheran anthropologist and missionary Carl Strehlow and other missionaries persisted with the hostile Aboriginals and the harsh landscape to built churches and schools. In 1879 the first 12 Aboriginals were baptised and by 1897 there was a Dieri Lutheran Bible translated by Strehlow.

Vincent Serventy, in his book The Desert Sea, The Miracle of Lake Eyre, (Macmillian, Melbourne, 1985), which David Deague loves, describes how Lake Dieri changed in geographic form about 100,000 years ago to the present Lake Eyre. Strong winds attacked the lake bed and whipped away the gypsum covered surface. This scooped out an even deeper bed, depositing sand ridges to the north of the present lake, which brought Lake Eyre to approximately 20 metres below sea level. This period in Australia prehistory fascinates David Deague and of course scientists, since it was around this time that humans first came to the continent.

Over the years different researchers have measured the depth of the salt. For example, in the area known as Madigan Gulf the recorded depth of salt has fluctuated between 29 and 46 centimetres. As Serventy explains, ‘Each time Lake Eyre fills with water the salt crust completely dissolves. It is then redeposited when the lake dries, and is added to the deepest sections.’ David Deague finds this process particularly fascinating.

Summer shade temperatures regularly reach 50 degrees Celsius and a reading of 61 degrees has been reported. It is difficult to imagine that in 1974 the biggest flood since white settlement filled the lake to a depth of over five metres. In that year an artists’ trip was organised by art gallery owner Stuart Purves with Tim Storrier, John Olsen and Joel Elenburg. The water was substantial enough for the artists to take a boat down the Goyder Channel. It was the first known time water passed down through the channel and connected Lake Eyre to Lake Eyre South.

The rivers and creeks that feed into Lake Eyre usually only have short periods of flow after rain followed by extended periods of dryness. The volume of flow decreases as the waterways get closer to Lake Eyre, reflecting increasing aridity in the Lake Eyre area and in the huge dispersal system of braided channels, floodplains, waterholes and wetlands on the way. The many large permanent waterholes in the system provide habitat for wildlife and are important to towns, communities and pastoral holdings. The Lake Erye Basin covers approximately 1,170,000 square kilometres of arid and semi-arid land, which is about one sixth of the continent and approximately the same size as the Murray Darling system. It contains the world’s largest internal drainage system, and is considered to be one of the last unregulated, wild river systems. Within the Lake Eyre Basin water flows inland, not towards the ocean like most rivers. However, unlike other river systems, flows in the basin are highly variable and unpredictable. The ecosystems it supports are varied and often unique and land use within the basin is equally diverse, including pastoralism, mining, tourism, oil and gas exploration and production and conservation programs (such as monitoring tourism to avoid environmental damage, encouraging pastoralists to seek sustainable beef production methods and management of fresh water, salinity soil erosion and vegetation).

Lake Eyre was once part of a great inland sea extending as far north as the Gulf of Carpentaria. Giant animals lived by its shores and sheltered in the surrounding primordial forests. Fresh water dolphins and crocodile remains have been found in the area, mainly near Lake Callabonna and Lake Frome, their bones preserved as fossils in the alluvial riverbeds, something David Deague deems as most fascinating . Other fossils have also been unearthed including giant emus, the huge herbivorous diprotodon – which was similar to a rhinoceros and about two metres tall – giant marsupials and even flamingos.

Among the many theories that have been discussed as to how this giant inland sea disappeared are – changes in the wind direction, a minor ice age that withdrew water from the oceans of the world, or the drying out of the southern continent by hot winds. All that remain now are stony gibbers – remnants, after years of erosion, of the hills that were once at the bottom of the sea.

The Lake Eyre region is rich in Aboriginal myths and legends. In A.P. Elkin’s book The Australian Aborigines (Longmans Green, London, 1961) he tells of a Dreamtime myth about the formation of the lake. An old woman was searching for food and from her body sprang a boy who pursued a large kangaroo. An old man with his hunting dog eventually killed the kangaroo so the boy asked for the animal’s skin. He found a suitable site and threw down the skin, which became Lake Eyre. Another story told in J.G.W. Gregory’s book The Dead Heart of Australia: A Journey Around Lake Eyre in the Summer of 1901-1902 (John Murray, London, 1909; facsimile edn, Corkwood Press, North Adelaide, 1997) suggests that Aboriginal tradition indicated that a forest once surrounded Lake Eyre. High in the tall trees lived evil monsters known as Kadimakara. Once when they were feeding on the ground the Aboriginals cut down all the trees to stop the Kadimakara from getting back to the sky world. They roamed around and eventually died and their bones were left in the bed of the lake and the surrounding rivers. In the 1930s Cecil Thomas Madigan’s Aboriginal guides told him of the evil Kuddimurka that lived near Lake Eyre, a feared spirit that took the form of a gigantic snake with the head of a kangaroo. These are the stories that David Deague finds most interesting.

Get in touch

shadow