Explaining Processes Flashcards
Explain the formation of headlands and bays.
Headlands and bays are formed when destructive waves hit against a discordant coastlines. Because in a discordant coastline the layers of rock are arranged perpendicular to the coastline , the softer rock gets eroded more easily and quickly while the hard rock gets eroded less easily and more less. The hard rock sticking out from the coast forms a headland and the indentation formed by the erosion of soft rock forms a bay. Overtime , as the destructive waves continue to erode the rock, the bay becomes larger and deeper, while the headland remains strong and resistant.
Explain the formation of a sand dune and the 5 stages of a sand dune
A sand dune is formed when prevailing winds blow sand particles across a beach , and then when wind is slowed down due to an obstacle or vegetation , sand is deposited. As more sand accumulates in this area , a small mound of sand is formed called an embryo dune in which marram grass grow to help bind the sand together. Then as more sand accumulates , a foredune develops with more vegetation. Eventually, these foredunes evolve into yellow dunes which is more stabalised so less sand is deposited, allowing more marram grass to grow. Although eventually the marram grass dies off because it needs fresh sand to grow. Then a grey dune develops which turns it into a greyish colour due to the organic matter that has grown. Lastly a mature dune develops which has a more complex plant life like heath and woodland.
Explain the process of longshore drift.
Firstly, prevailing winds blow across the surface of the sea, creating waves to approach the coast at an angle. This causes the swash to carry sediment from the sea to the coast in the direction of the waves. Then the backwash carries sediment from the beach to the sea at a right angle due to gravity. This constant movement of the swash and backwash causes sediment to be transported along the coastline in a zig zag pattern in the direction of the prevailing winds, forming longshore drift.
Explain one cause of coastal flooding.
One cause of coastal flooding is tsunamis . Tsunamis are formed by ….. .
Tsunamis are large , fast - moving waves and when they approach the shore, they grow larger and taller. Therefore, these large waves are pushed inland with a lot of force , and rush towards the buildings and city , flooding the area.
