Fraser Island’s Sand Dune Systems
Dune systems are the building block of Fraser Island. The sand on the Island is the result of erosion of the Great Dividing Range along the East Coast of Australia. A continental drift pattern pushes this sand up onto the coast of SE Queensland. It is along this coast that there are a group of sandy islands that include Moreton Island and Stradbroke Island.
Dune System:
As sand is deposited onto the east coast of the island, it is blown up the beach and creates the first dunes called fore dunes. Generally, vegetation such as spinifex grasses stabilise the sand and prevent it from moving inland. If there has been a disturbance in the vegetation, the sand will be pushed across the island by the wind forming a “U shaped” dune system called a Parabolic dune. Parabolic dunes move in giant “sand waves” across the island covering over older dune systems that may have been previously stabilised by vegetation. It is common to see dead trees sticking out the top of the sand on these dunes.
Past of Fraser Island:
Many dune systems have formed on Fraser Island over the past 100 000 years. There are currently approximately 7 layers of dunes. Most of these have been stabilised through vegetation. The dune formation is part of the evolution of Fraser Island and will continue for thousands of years to come. Experts estimate that the island is growing at roughly one metre per year and currently, Fraser Island is 123kms long and has an average width of 15kms. The highest dune on the island is 240m above sea level