Landforms of deposition Flashcards
When does beach formation usually occur?
In the summer months when the weather is calmer
Where do beaches typically form?
In sheltered areas such as bays through deposition via constructive wave movement
What is the primary characteristic of constructive wave movement?
The swash is stronger than the backwash
What natural feature can be created by blown sand at the backshore of a beach?
Sand dunes
What happens when a constructive wave carries sediment up the beach?
The largest material is deposited along the upper reach of the swash
What occurs as the backwash moves back down the beach?
It loses water and therefore energy due to the porosity of the sand
What is the result of the backwash losing energy as it travels?
The deposition of sediment gets progressively smaller
What forms at the top of the beach when a destructive wave occurs due to a storm?
A ridge called a berm
Fill in the blank: Beaches form through deposition via _______ wave movement.
constructive
True or False: The swash of a destructive wave is stronger than the backwash.
False
What are sand dunes?
A dynamic environment with quick changes
Where are sand dunes usually found?
At the rear of sandy beaches due to strong onshore winds
How are embryo dunes formed?
Sand grains are trapped and deposited against obstacles like rubbish, rocks, or driftwood
What causes dune ridges to move inland?
Onshore winds push the seaward side to the leeward side
What two factors interact to help form sand dunes?
Winds and vegetation
What is the first step in the formation of a sand dune?
Windblown sand is deposited against an obstruction
What happens as more sand particles are caught by an obstruction?
The dunes grow in size, forming rows at right angles to the prevailing wind
What process helps to stabilise dunes over time?
Colonisation and fixation by vegetation in a process called succession
What are pioneer species?
The first plants that colonize and stabilise sand dunes
What challenges do pioneer species face?
Salinity, lack of moisture, wind, temporary submergence by wind-blown sand, rising sea levels
Fill in the blank: Sand grains are trapped and deposited against any _______.
obstacle
True or False: Sand dunes are a stable environment.
False
What is a spit?
An extended stretch of sand or shingle that extends out to sea from the shore
What causes spits to form?
A change in the shape of the coastline or the mouth of a river that prevents a spit forming across the estuary
Do spits always have a hooked end?
No, a spit may or may not have a ‘hooked’ end depending on opposing winds and currents
What is a notable example of a spit?
Spurn Point, which stretches for three and half miles across the Humber Estuary in the northeast of England
What is the first stage of spit formation?
Sediment is transported by the action of longshore drift
What occurs when the coastline changes direction during spit formation?
A shallow, sheltered area allows for deposition of sediment
Why does more deposition occur as a spit forms?
Due to increased friction
What happens as a spit builds up to sea level?
It extends in length
What happens if the wind changes direction during spit formation?
The wave pattern alters and results in a hooked end
What type of environment forms behind a spit?
A sheltered area
What is deposited in the sheltered area behind a spit?
Silts to form salt marshes or mud flats
What is formed when a spit grows across a bay and joins two headlands together?
A bar of sand (sandbar)
A sandbar can affect navigation and coastal ecosystems.
What can cause sandbars to form offshore?
The action of breaking waves from a beach
Offshore sandbars can influence wave patterns and coastal erosion.
