Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Geog 8.2 - Characteristics + Formation of Coastal Landforms > Depositional Landforms > Flashcards

Depositional Landforms Flashcards

1
Q

What is a beach?

A
  • a depositional landform that stretches from the low to high tide line
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

How is a beach formed?

A
  • created when sediment is deposited near coastline, when waves lose their energy
  • larger sediment, left behind from winter storms, is found near top of beach bc backwash is often weaker than swash bc water quickly percolates into sand
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What is a shingle beach?

A
  • beach w steep gradient bc waves easily percolate into sand, dec. effect of backwash erosion + inc formation of sediment into a steep sloping back
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What is a sandy beach?

A
  • flatter + wider beach, bc smaller particles are evenly distributed + water takes longer to percolate into sand so more sand is removed w backwash
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

What are the diff beach profile features?

A
  • ridges + runnels
  • storm beaches
  • cusps
  • ripples
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What are ridges + runnels?

A
  • raised areas (ridges) + intervening depressions (runnels) on shallow, sandy beaches, formed by interaction of tides, currents, sediments + shallow beach topography
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What are storm beaches?

A
  • ridge of boulders + shingle thrown to back of beach by largest waves at high tide
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

What are cusps?

A
  • self sustaining, semicircular depressions formed by waves breaking directly onto beach w a strong swash + backwash
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

What are ripples?

A
  • ridges + intervening depressions that develop on sandy beaches as a result of wave + tidal movements
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

What are the 2 diff types of beach?

A
  • swash-aligned beaches
  • drift-aligned beaches
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

How are swash-aligned beaches formed?

A
  • when prevailing winds cause waves to break parallel to coast, LSD is limited, causing swash + backwash to move material up + down beach so sediment doesn’t travel far along beach
  • this creates smoothly curved, concave beaches
  • wave refraction May dec speed of high energy waves, forming a shingle beach
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

How are drift-aligned beaches formed?

A
  • when prevailing winds cause waves to break at an oblique angle to coast, swash occurs at an angle + backwash runs perpendicular to beach, causing LSD to transport material far along beach
  • this may lead to formation of a spit at end of beach
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is a spit?

A
  • a long narrow strip of land formed when LSD causes beach to extend out to sea, bc of a change in direction of coastline
  • sediment projection can create a salt marsh bc of sheltered, saline envi w a lower speed of water flow, allowing deposition of finer sediments to occur
  • length of spit depends on changing currents or rivers, which prevent deposition of sediment so a spit can’t extend across an estuary
  • a recurved end can form from a change in wind/wave direction
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What is a compound spit?

A
  • a spit w multiple recurved ends formed over time when recurved end is abandoned + a new spit is formed on old recurved end
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What is a tombolo?

A
  • a spit connecting mainland to an offshore island, formed by wave refraction off coastal island, dec wave velocity + leading to deposition of sediments
  • if low lying, it may be covered at high tide
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

What are offshore bars/sandbars?

A
  • an offshore region where sand is deposited, formed when waves break bc don’t have enough energy to carry sediment to shore
  • can also form when backwash from destructive waves remove sediment from a beach
  • they may absorb wave energy, dec erosion in some areas
17
Q

What are barrier beaches?

A
  • a beach/spit extending across a bay to join 2 headlands, which traps water behind it to form a lagoon separated from sea
  • some may have formed from rising sea lvls after last glacial period, when meltwater from glaciers deposited sediment in coastal zone
  • if it becomes separated from mainland, it forms a barrier island
18
Q

How are sand dunes formed?

A
  • prevailing winds blow sediment to back of beach which requires large quantities of sand + a large tidal range
  • this allows sand to dry, so is light enough to be picked up + carried by frequent onshore winds to back of beach
  • sand dunes can be stabilised + developed through vegetation succession
19
Q

Describe how sand dunes stabilise + develop by vegetation succession.

A
  • sand deposited above high tide mark forms a embryo dune where pioneer species (e.g. sea rocket), which are resistant + able to survive in salty sand, w its roots helping to bind dunes together, grow
  • a fore dune is formed once sand dune becomes bigger + is yellow in colour
  • over time, decaying organic matter adds nutrients + humus to soil, turning dune grey + allowing marramgrass to grow which has long roots to seek water + stabilise dune
  • dune slacks form when water table rises towards surface + water is trapped in depressions between dunes
  • mature dunes form when larger plants can colonise area + climatic climax occurs when trees can colonise area
20
Q

How does tidal sedimentation in estuaries occur?

A
  • deposition occurs in river estuaries (where river meets ocean) bc of change in velocity from a river to an ocean
  • when waterflow from river meets w incoming tides + waves from sea, flow virtually stops so water can’t carry small, fine sediment in suspension + forms mud that builds up until it’s above water lvl
  • more sediment is trapped by colonising pioneer plants +.mudflats + saltmarshes May develop due to sedimentation
21
Q

What are salt marshes?

A
  • build up of salt + minerals in sheltered bays or behind spits, which can be further stabilised + developed by vegetation succession
22
Q

Describe how salt marshes can be stabilised + developed by vegetation succession.

A
  • gut weed + blue green algae grows on mud, in which their roots help to bind together
  • during pioneer stage cordgrass + glasswort grow + their roots start stabilising mud allowing estuarine to grow
  • causes height of salt marsh to inc + plants no longer need to be adapted for salty conditions
  • this means a wider range of plants can grow (e.g. rush) which improves soil conditions to form a meadow
  • eventually, succession reaches its climate climax when shrubs + trees can colonise area bc saltmarsh is only submerged 1/2 times per yr
23
Q

What are mangroves?

A
  • trees adapted to grow in saline, low O2 conditions that develop in coastal swamps in tropical regions, meaning envi around them is constantly changing w tides
  • can stabilise shorelines w roots, protect areas from erosion + provide envi for wildlife

Geog 8.2 - Characteristics + Formation of Coastal Landforms (4 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions