Landscape developments Flashcards
How do headlands and bays form?
Headlands form from slow-eroding hard rock, while bays form from faster-eroding soft rock on discordant coastlines.
What are berms ?
Series of ridges which mark successively lower high tides and as the cycle goes from spring to neap.
What are cusps ?
Semi-circular shaped depressions which form when waves break directly onto the beach.
What are cliffs and how do they form?
Cliffs form where waves erode the base of a rock face, leading to undercutting and eventual collapse.
What is a wave-cut platform?
A flat, rocky surface left visible at low tide as a cliff retreats.
Describe the formation of caves, arches, stacks, and stumps.
Caves form from erosion of cracks, arches form when erosion breaks through, stacks are isolated pillars left after arches collapse, and stumps are further eroded stacks.
What is a blowhole and how does it form?
A blowhole forms when a cave extends upward and breaks through to the surface, forcing air and water upwards.
What are geos?
Narrow, steep-sided inlets formed when erosion widens a crack that eventually collapses.
How do beaches form?
Constructive waves deposit sand, pebbles, and shells along the shore.
What are the types of beaches?
- Sandy Beaches: Sheltered bays, gently sloping.
- Shingle Beaches: Formed by stronger waves, steeper profile.
How do spits form?
Spits form when longshore drift transports sediment along the coast, there is a change in direction at the coastline, salt marshes can be created behind the spit.
What features can be associated with spits?
- Hooked End: Redirected growth due to secondary currents.
- Salt Marshes: Form in sheltered areas behind the spit.
What are bars and how do they form?
Bars form when a spit extends across a bay, connecting two headlands and blocking a body of water.
What forms behind bars?
Lagoons, often filling with sediment over time.
What is a tombolo?
A spit that extends and connects an island to the mainland.
What are barrier islands?
Offshore bars that rise above sea level, forming islands parallel to the coast.
How do sand dunes form?
Wind-blown sand accumulates above the high-tide mark, stabilized by vegetation.
What is the sequence of development of sand dunes ?
Sand may become trapped by obstacles - First dunes to develop are embryo dunes and are suitable for colonisation - Upwards growth of embryo dunes raises height of them creating foredunes ( yellow dunes ) - Dunes gradually become fixed as more vegetation colonises - In places dune slack occur which are low-lying areas which can flood - Behind yellow and grey dunes the supply is cut off giving smaller dune features.
What determines the development of drift and swash aligned beaches ?
The angle in which waves approach the coastline
Characteristics of swash-aligned beaches ?
shoreline is aligned in such a way that the waves (swash) approach the shore directly, or nearly directly, from the direction of the prevailing wind, experiences minimal longshore drift, can be found on irregular coastlines
Characteristics of drift-aligned beaches ?
They are shaped by the process of longshore drift, where the direction of the beach is aligned with the movement of sediment along the shoreline, have considerable amounts of sediment transported along them.
