geography: coasts. processes and landforms. · pablo fraile jurado pablo fraile jurado 1. processes...
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Pablo Fraile Jurado
Pablo Fraile Jurado
1. Processes and landforms. Pablo Fraile Jurado 2. The andalusian case. Pepe Ojeda Zújar 3. Coast of the world. Miriam Fernández Núñez
Introduction ◦ Structure of the Earth and where the sea is. ◦ Physiography of the ocean floor
Processes in the coast ◦ Waves ◦ Tides ◦ Sea levels ◦ Other processes ◦ Geological structure of the ebmerged areas
Landforms ◦ Exposed landforms ◦ Protected landforms
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Middle scale phenomena: http://www.stumbleupon.com/su/2yfJOd/primaxstudio.com/stuff/scale_of_universe/
Structure of the Earth and where the sea is
Structure of the Earth ◦ Inner core
◦ Outer core
◦ Mantle
◦ Crust
http://www.stumbleupon.com/su/2yfJOd/primaxstudio.com/stuff/scale_of_universe/
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71% of crust is convered by ocean waters
70% of the landmasses are in the Hnorthen Hemisfere
Continental margins ◦ Continental plain
◦ Continental slope
◦ Continenal rise
Deep Ocean basins ◦ Abyssal plains
◦ Deep-sea trenches
◦ Seamounts
Midocean ridge
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Processes ◦ Waves ◦ Tides ◦ Sea level ◦ Storms ◦ Hardness
Landforms ◦ Exposed landforms Beaches
Profiles Sand budgets
Barrier eaches Spits Cliffed coasts Deltas
◦ Protected landforms Estuaries Marshes
Waves ◦ Mainly, 2 types of waves: Wind waves Swell waves (+capilarity waves)
◦ Factors Fetch Wind speed Water depth
◦ Characteristcs Height Lenght Speed Period Propagation direction
Wind waves
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Swell waves
Wave definition
Types of waves ◦ Wind waves ◦ Swell waves ◦ Capilarity waves
Wave propagation ◦ Deep waters ◦ Shallow waters
Refraction Diffraction Reflection; http://www.youtube.com/watch?v=NEVtNJ_tcfg
http://www.youtube.com/watch?v=NEVtNJ_tcfg
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Wind waves: http://www.youtube.com/watch?v=um5ahIZx87A
Swell waves: http://www.youtube.com/watch?v=rnKEdmX6qco
Tsunami in deep sea: http://www.youtube.com/watch?v=OdhfV-8dbCE
Tsunami in the coast: http://www.youtube.com/watch?v=w3AdFjklR50
http://www.youtube.com/watch?v=um5ahIZx87Ahttp://www.youtube.com/watch?v=rnKEdmX6qcohttp://www.youtube.com/watch?v=OdhfV-8dbCEhttp://www.youtube.com/watch?v=OdhfV-8dbCEhttp://www.youtube.com/watch?v=OdhfV-8dbCEhttp://www.youtube.com/watch?v=w3AdFjklR50
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Tides ◦ What tides are.
◦ 3 types of tides according their ranges:
Macro. http://www.youtube.com/watch?v=u3LtEF9WPt4
Meso.
Micro
◦ 2 types of periodicity
Diurnal
Semi-diurnal
◦ http://dusk.geo.orst.edu/oceans/PPT/TidalCycleV2.html
http://www.youtube.com/watch?v=u3LtEF9WPt4http://dusk.geo.orst.edu/oceans/PPT/TidalCycleV2.html
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Sea level and geoid
Absolute and relative mean sea level changes
Mean sea level in the geological past
Present and future mean sea level changes
REAL SEA LEVEL SHAPE
Pablo Fraile Jurado
Departamento de Geografía Física y A.G.R. - Universidad de Sevilla
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+42 m
+36 m
MEAN SEA LEVEL SHAPE
Los mapas topográficos se elaboran considerando estas diferencias.
Pablo Fraile Jurado
Departamento de Geografía Física y A.G.R. - Universidad de Sevilla
MEAN SEA LEVEL SHAPE
Los mapas topográficos no consideran estas diferencias, que localmente pueden ser de magnitud media (hasta 50 cm),
Pablo Fraile Jurado
Departamento de Geografía Física y A.G.R. - Universidad de Sevilla
CAMBIOS DEL NIVEL DEL MAR
Pablo Fraile Jurado
Departamento de Geografía Física y A.G.R. - Universidad de Sevilla
http://upload.wikimedia.org/wikipedia/en/4/44/Phanerozoic_Sea_Level.png
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CAMBIOS DEL NIVEL DEL MAR
Pablo Fraile Jurado
Departamento de Geografía Física y A.G.R. - Universidad de Sevilla
Other processes: ◦ Storms
◦ Wind
◦ Tsunamis
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Geological structure of the coast ◦ Hardness / softness of materials
Hard rocks
Soft rocks
Sand
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Geological structure of the coast ◦ Hardness / softness of materials
Hard rocks
Soft rocks
Sand
Vegetation
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Exposed coasts ◦ Wave as main factor ◦ Relationship between energy input from waves and
the land: Balanced: beaches.
Positive: deltas
Negative: cliffs
Protected Coasts ◦ Controlled by Tides Macro and mesotidal coasts: marshes
Microtidal coasts: lagoons
Beaches ◦ What a beach is.
◦ Dissipating energy
◦ Profiles in beaches
◦ Sand budgets
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Barrier beaches ◦ Beaches controlled by transversal dynamics
◦ Sediment budgets from rivers
◦ Not only barrier islands
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Spits ◦ Beaches controlled by longitudinal dynamics
◦ Sediment budgets from… elsewhere
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Deltas ◦ Controlled by the sediment suplies from rives
◦ Neutral or positive balance between the supplies and the erosion.
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Cliffed coasts ◦ Eroding coasts
◦ Types of cliffs:
Depending on the size
Depending on the hardness
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Exposed coasts ◦ Wave as main factor ◦ Relationship between energy input from waves and
the land: Balanced: beaches. Positive: deltas
Negative: cliffs
Protected Coasts ◦ Controlled by Tides Macro and mesotidal coasts: marshes
Microtidal coasts: lagoons
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And what if waves are not the key factor? ◦ Tides become into the main factor in mesotidal and
macrotidal coasts.
◦ Marshes
Salt marshes
River marshes
◦ Lagoons
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Processes ◦ Waves ◦ Tides ◦ Sea level ◦ Storms ◦ Hardness
Landforms ◦ Exposed landforms Beaches
Profiles Sand budgets
Barrier eaches Spits Cliffed coasts Marshes Deltas
◦ Protected landforms Marshes Estuaries