Coastal Landscapes and Change - enquiry q1 Flashcards
Littoral Zone
a coastal area/zone - can be divided into subzones
- offshore, nearshore, foreshore, backshore, coast
Coastal plains
the land gradually slopes towards the sea across an area of deposited sediment - aka alluvial coasts
- e.g. sand dunes and mud flats
North Northumberland
Primary coasts
are dominated by land based processes
- e.g. deposition at the coast from rivers or new coastal land from lava flows
Nile River Delta
Secondary coasts
are dominated by marine erosion or deposition processes
Emergent coasts
where the coats are rising relative to sea level
- e.g. due to tectonic uplift
Hudson Bay, Canada
Submergent coasts
are being flooded by the sea, either due to rising sea levels and/ or subsiding land
Western Norway
Estuarine coastline
- gradually transition from land to sea
- extensive mud flats
- at mouths of rivers, sometimes form slat marshes
The Thames mouth
Sandy coastline
- lots of sand dunes
- high tide covers beaches
- vegetation prevents erosion
Whitby beach, Yorkshire
Cliffed coastline
- low tide exposes rocky platforms
- vertical steep rocks or shallow angled rocks
- transitions from land to sea is abrupt
Whit cliffs of Dover, Kent
Sub-aerial processes
land based processes that occur above the waterline. They include weathering and mass movement, which happen on the cliff rocks.
Marine erosion
a type of erosion facilitated by wave and tidal action
- the repetitive nature of wave action produces a mechanism able to erode loose soils/sands and wear down rock cliff surfaces as well
- e.g. hydraulic action, abrasion, attrition
Cliff profile
the height and angle of a cliff face and its features
- e.g. wave cut platform
Erosion resistance
rocks forming cliffs vary in terms of their resistance to erosion and weathering
Geology
the study and understanding of rocks
- their type and arrangement
Geological structure
the arrangement of rocks in 3 dimension
~ strata - layers of rock within an area
~ deformation - the degree to which rock units have been deformed (tilted or folded) by tectonic activity
~ faulting - the presence of major fractures that have moved rocks from their original positions
Strata
layers of rock within an area
Deformation
the degree to which rock units have been deformed (titled or folded) by tectonic activity
Faulting
the presence of major fractures that have moved rocks from their original positions
Concordant
(Pacific coasts) concordant coasts are generated when rock strata run parallel to the coastline
Discordant
(Atlantic coasts) form when different rock strata intersect the coast at an angle, so geology varies along the coastline
Dip
the angle of the rock strata in relation to the horizontal caused by tectonic activity
- horizontal dip, seaward dip
Lithology
the rock type and its main characteristics
- igneous, metamorphic, sedimentary0
Joint
fractures in rocks created without displacement of rock
- displacement of the rock is not observable
Fault
the fracture in the rock strata due to strain in which the displacement of the rock is observable