School of Geography - Theses

Permanent URI for this collection

Search Results

Now showing 1 - 1 of 1
  • Item
    Thumbnail Image
    The morphology and evolution of rock coasts over eustatic cycles in temperate, wave dominated environments
    Bezore, Rhiannon ( 2019)
    Rock coasts comprise 80% of the world’s shorelines and about 50% of the Victorian coast. Their morphology and evolution over time is the result of marine and subaerial erosional processes that carve features such as sea cliffs, shore platforms, and sea stacks out of the landscape. Rock coasts, therefore, evolve over multiple sea level cycles and create dynamic landscapes on an interglacial timescale. Sea level has risen and fallen over geologic time, with coastal features being formed during sea level high stands. While most coastal landforms found along the modern coast were formed over the past 6,000 years, older coastal features have also been preserved over multiple eustatic cycles, both above and beneath modern sea level. As coastal landforms are formed at or very near sea level, preserved paleo-shoreline features can be used as proxies to reconstruct past sea levels on a regional scale, which had not previously been done for the coast of Victoria, Australia. In this study, an integrated aerial LiDAR and bathymetric multibeam dataset from +20 to -80 m water depth was used to precisely map and quantify the morphology of the rock coast features along the coast of Victoria from Port Fairy in the west to Wilsons Promontory in the east and to analyze the relation between the features’ elevations and the sea levels at which they first formed. This was completed for both the modern coastline as well as paleo-shoreline landforms found 50-60 m below modern sea level, where the offshore geology reflected the onshore geologic units, allowing for an analogous study. These preserved features are believed to have formed during the MIS 3 high stand, during which time sea level most closely matched their average present depths. The culminating results provide not only the first study of the precise morphology of these submerged features in Victoria but also have wider applications for modelling sea level and rocky coast evolution in other temperate, wave dominated environments.