1. The Australian Coast: Introduction

The 30,000-km-long Australian coast surrounds the world’s oldest, flattest and driest continent with aspects of the continent reflected in the nature of the coast. Being a continent it is also surrounded by three oceans and several seas which deliver waves, tides and sediment to build beaches and barrier systems which occupy half the coast, together with estuaries, deltas and rocky shore. The geology ranges from ancient cratons in the west and centre to more recent oregons across the eastern third and a series of sedimentary basins resulting from buckling during the continent’s northward drifting. Coastal processes can be divided into a northern coast dominated by meso to mega-tides, low sea waves and southeast trade winds and a southern coast with micro-tides, exposed to moderate to high swell and west through south winds. The waves, tides and sediments combine to produce a range of beach types and states that have distinct regional variation linked to the coastal processes. Likewise, the coastal barriers vary considerably around the coast with regional variation in nature, extent and volume. The coast is divided into a hierarchy of provinces, divisions, regions and primary and secondary sediment compartments, which are used as the framework for this book. This chapter reviews the coastal processes that operate around the coast and range of coastal systems they produce.