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Costal Processes in the Barrenjoey Head
Above is as image of the Barrejoey Headland wave-cut platform, formed through the processes of Hydraulic Action, Corrosion and Abrasion. (for more detail click the button at the bottom of the page) These two processes eat away at the bast of the cliff and slowly over hundreds of years, move the cliff further and further back inland. This impacts human activities as slowly over time, the solid ground is being broken away by the processes described above, causing the recession of the land. This could impact housing or any buildings like lighthouses on cliff faces. It's location can be seen on a map by clicking the 'See Map' button above.
This is an example of Honeycomb Weathering, or fretting, occurring on a sandstone cliff-face. Honeycomb weathering occurs as a result of saltwater spray being sprayed over the rocks from the sea by wind. The salt then crystallizes on the rocks in tiny pores in the rock, widening the pores, and making the rock even more vulnerable to other types of weathering. This could impact on human activities as fretting is known to cause weakness in the rocks, leading to these rocks collapsing. This is a obvious health risk for anyone who is either above or below a rock that has been subject to honeycomb weathering.
The image above shows the Barrenjoey Tombolo, taken from the lighthouse track on the headland. (This image was also used as the background for the website) The ocean side of the Tombolo can be seen on the left (the waves are visible), and the right is the Pittwater side, with the Barrenjoey Boat house and Jetty visible. The Tombolo has largely had a positive impact on human activities in the area, as it has been very useful gaining access to the Barrenjoey Lighthouse, and has even been used as a caravan park in the past.
The Tombolo is formed through the processes of Long-Shore Drift where sediments are transported by the motion of the waves (swash and backwash). Over a long period of time, the sediment has built up to connect the mainland with the island, to form the tombolo. The hand-drawn diagram below shows this relationship between the direction of long-shore drift and the direction of the movement of sediment, which created the tombolo.
FOR EXTRA INFORMATION ON THESE PROCESSES CLICK THE BUTTON BELOW!
