Block 3 (Landforms + Their Landscape Systems, Their Distinctive Features + Distribution) Flashcards
What is a low energy coast?
Sandy or estuarine coastline, dominated by deposition
What waves are predominantly found on a low energy coastline?
Constructive waves
What process is predominantly found on a low energy coastline?
Deposition
What is the sediment budget on a low energy coastline?
Positive - production + delivery rate exceeds erosion rate
Where are low energy coasts found?
- Sheltered bays
- Estuaries
What are common landforms for a low energy coast?
- Sandy beach with gentle gradient
- Spit
- Sand dunes
What are some examples of low energy coastlines?
- German Baltic Coast
- Netherlands
- East Africa
- South-East UK
Why do low energy coasts exist?
- Divergence of orthogonals in bays (product of wave refraction)
- Limited fetch/duration (sheltered areas) causes low energy waves
Case study of low energy coastline + details
German Baltic Coast
Location:
- N.Europe
- N. Germany, between Danish + Polish borders
- 2481km long
Why is it low energy?
- Very sheltered - so waves have low fetch + low duration - low energy
Characteristics:
- Beaches (Large deposition by constructive waves, usually shallow gradients, often backed by sand dunes) (Most important beach + dune system is Fischland-Darss-Zingst peninsula, on Hiddensee + Rugen islands)
- Spits (Positive sediment budget, moved by LSD, continues when coastline changes direction) (2 spits extending into Pomeranian Bay - Usedom island)
What is a high energy coast?
Rocky coastline dominated by erosion
What waves do high energy coasts predominantly have?
Destructive waves
What process is dominant on high energy coasts?
Erosion
What sediment budget do high energy coasts have?
Negative - erosion rate exceeds production + delivery rate
Where are high energy coasts?
Exposed headlands/coasts
What are common landforms on high energy coasts?
- Cliffs (steep + rocky)
- CASS sequences
- Wave cut platforms
What are some examples of high energy coasts?
- West coast UK (Atlantic fetch)
- East facing low latitude areas
Why do high energy coasts exist?
- Convergence of orthogonals on headlands (product of wave refraction)
- Long fetch/duration
- Strong winds
What are swell waves?
- Strongest, highest waves
- Long period
- Generated out at Sea
Case study of high energy coastline + details
Dyfed Coast
Location:
- SW Wales
- Dyfed is a Welsh county, with Pembrokeshire in SW part
- 536km
- Irish Sea to W, Bristol Channel in S
Why is it high energy?
- Very exposed - so waves have a long fetch (over N.Atlantic) + long duration - high energy
Characteristics:
- Cliffs (Form through mass movements + weathering breaking down rock then waves removing it, usually steep (40+ angle)+rocky)(E.g steep limestone cliffs at St Govan’s Head)
- Wave cut platforms (Form through constant destructive waves making wave cut notch which causes overhang then collapses leaving flat base)(E.g are of limestone cliffs at St Govan’s Head)
- CASS systems (Form when headlands exposed to converging destructive waves)(E.g Carboniferous limestone headlands has formed ‘Green Bridge’ - arch 24m high, 20m wide - and ‘Stack Rocks’ - stacks 36m high)