Section B - Coastal Landscapes and Change Flashcards
(148 cards)
What is a high-energy environment?
Where the rate of erosion exceeds the rate of deposition
What is a low-energy environment?
Where the rate of deposition exceeds the rate of erosion
Characteristics of high energy coastlines?
Older resistant rock (igneous, sedimentary and metamorphic) that are all resistant to the erosive powers of the sea, wind and rain
Characteristics of low energy coastlines?
Weaker and younger sedimentary rocks including clays, chalks, sand and sandstone - more susceptible to erosion - leaves areas of low, flat relief or coastal plains
Inputs of the coastal system (4)
Marine - waves, tides, storm surges
Atmospheric - weather/climate, climate change and solar energy
Land - Rock type and structure, tectonic activity
People - Human and coastal management
Processes of the coastal system (5)
Weathering
Mass movement
Erosion
Transport
Deposition
Outputs of the coastal system (3)
Erosional landforms
Depositional landforms
Different types of coast
What is the littoral zone?
An area of the coastline which has all features of a complex coastal system - inputs, outputs and processes
The four ways in which coasts can be classified?
Geology - this can create rocky, sandy, estuarine, concordant and discordant coasts
Energy levels - high or low energy coastlines
Balance between erosion and deposition - creating either erosional or depositional coasts and their features
Changes in sea level - creating emergent or submergent coasts
What is coastal morphology?
The shape and form of coastal landscapes and their features - related to underlying geology, rock type and geological structure (lithology)
What is strata?
Layers of rocks
What are bedding planes?
Horizontal cracks - natural breaks in the strata caused by gaps in time during periods of rock formation
What are joints?
Vertical cracks - Fractures caused by either contractions as sediments dry out or by earth movements during uplift
What are folds?
Formed by pressure during tectonic activity which makes rocks buckle and crumple (EG Lulworth Cove)
What are faults?
Formed when the stress or pressure to which a rock is subjected exceeds its internal strength causing it to fracture - the faults then slip or move along fault planes
What does dip refer to?
The angle at which rock strata lie (horizontally, vertically, dipping towards to sea or dipping inland)
Characteristics and examples of igneous rocks?
Resistant and permeable (EG granite) - very slow recession rate - recedes at less than 0.1cm per year
Characteristics and examples of sedimentary rocks?
Formed in strata (EG limestone, chalk, sandstone and shale) - recedes moderately quickly (0.4-10cm per year)
Characteristics and examples of metamorphic rocks?
Very hard, impermeable and resistant (EG marble and schist) - slow recession rate - 0.1-0.3cm per year
What are concordant coasts?
Where bands of more resistant and less resistant rock run parallel to the coast
What are Dalmatian coasts?
Coastlines where valleys and ridges run parallel to each other - when they are flooded the tops of the ridges remain above the water as a series of offshore islands (EG Dalmatian coast in Croatia)
What are Haff coasts?
Long spits of sand and lagoons aligned parallel to the coast
What are discordant coastlines?
Where the geology alternates between bands of more resistant and less resistant rock - forms bays at low resistance and headlands at more resistance
What are headlands?
Headlands force the oncoming waves to refract or bend – concentrating their energy at the headlands – this increases the waves’ erosive power which leads to a steepening of the cliffs and their eventual erosion into arches and stacks