How are coastal landscapes formed

• geomorphic processes include weathering, erosion, and mass movement
• physical or mechanical weathering- produces smaller fragments of the same rock, no chemical alteration takes place
• chemical weathering- causes decay of rock, involves chemical reactions between moisture and some minerals in rock, may alter chemical and mineral composition. happens faster in warm weather, meaning its faster in tropics. however carbonation may more effective in cold as it is more soluble in cold water
• biological weathering- consists of physical actions like growth of plant roots or chemical processes like chelation by organic acid
• mass movement- occurs when forces acting on slop exceed forces keeping materials on slop (more gravity than friction). Most significant mass movements add material to sediment budget like rockfalls, slides, and slumps
• wave erosion- abrasion (rocks rubbing against each other), attrition (rock particles colliding with each other), hydraulic action (waves breaking against cliffs)
• deposition is when sediment is deposited due to loss of energy.

  -when rate of accumulation exceeds rate of removal

  -when waves slow down immediately after breaking

  -during backwash when water percolates beach material
• fluvial erosion- occurs in upper catchment, similar processes to wave erosion
• fluvial deposition- as rivers enter sea velocity drops. larger particles are deposited first and smaller particles are carried further downstream. melting of fresh and salt water leads to flocculation of clay particles when they lump together and sink to sea floor
• aeolian erosion- wind can only carry very fine pieces of sand, restricting erosion by abrasion to a height of 1m with limited effect, velocity increase of 2-4m per second increases erosive effect. dry sand is more erosive.
• geos and blow holes- geos are narrow steep sided inlets, Huntsman leap in 35m deep. if part of the geo ceiling collapses it becomes a blow hole
• caves, arches, stacks, and stumps- form when fault on headlands becomes cave and erodes all the way making an arch and when the arch collapses under gravity it becomes a stack and erosion and base of stack makes it a stump
• onshore bars- if a spit continues to grow across an indention like a cove or bay, forming a lagoon with brackish water on landward side. 100m wide bar at Slapton sands thought to be formed this way
• tombolos- beaches that connect the mainland to an offshore island, often spits that continued to grow seaward, may be from sea level change. Chesil beach 30km long shingle beach thought to be formed from a spit
• spits-long narrow beaches of sand or shingle that are attached to the land at one end and cross a bay or estuary, formed from LSD. if it forms across an estuary growth may be restricted from river currents. in sheltered areas they may have a salt-marsh behind them
• cliffs and shore cut platforms- when destructive waves break repeatedly against sloping cliffs undercutting can occur and weakens support for the cliff until it eventually collapses. they are predominantly formed by weathering like solution, freezethaw, and salt crystalization.
• bays and head lands- they form adjacent to each other due to the presence of bands of different rocks. they form on discordant coastlines.
• deltas- large areas of sediment found at the mouths of rivers, sediments are deposited by rivers and tidal currents. form when rivers entering sea carry large sediment loads, tidal ranges are low, low energy environments. they consist of the upper delta plain, the lower delta plain, and the submerged delta plain.