geo case studies

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arid weathering chemical
wetting and drying - minerals rock saturated, water evaporates, rock breaks up, hydration - anhydrite absorbs water turning to gypsum, oxidation - minerals eg, iron rust increase volume
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arid namib desert
hyper <30mm ppt, fog, 55 million years old, 50-120 by 1200km, SE p wind, ventifacts - abrasion, flat surfaces, desert pavement - deflation, layer of stones, yardangs - mega 20km long 1km wide 500m high between luderitz and mouth of orange river
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arid tafoni crystal peak utah
4m wide can be 20m, salt crystallisation and carbonation
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arid grand canyon arizona
exogenous river, 1600m deep, 6 million year process, hydraulic action, abrasion
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arid antelope slot canyon arizona
>25mm ppt per hour ephemeral river, much sediment, little infiltration inception, abrasion deepens 30m deep
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arid monument valley utah
300m high, 150mm ppt, butte - taller, mesa - wider, spire eg. totem pole - very tall, sedimentary, shinarump caprock - thin resistant, deshelley sandstone - resistant but joints, organ shale - weak, water isolates blocks, parallel erosion
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arid alluvial fans panamint range death valley california
stream exits canyon loses velocity largest sediment deposited first, widens out, bajada - line of fans
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arid playas / salt flats bonneville salt flats utah
high evap rates, salts rise up layers build up to 5 feet deep, process repeats, 40 square miles
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arid sonoran desert
>200mm ppt, SW USA, 30 degrees autumn, cryptobiotic crust - easily damaged, covers 70% SW, 250 years to recover
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arid plant adaptations
saguaro cactus - loose 80% water, can store 5 tonnes water, wide roots, creosote bush - stomata closed during day, long lateral tap roots, extract soil moisture, verbena - desert annuals, germinate post rainfall, flower, seed die avoid drought
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arid animal adaptations
gila monster - nocturnal, burrows, excrete pellets, jack rabbit - large ears, pale fur, kangaroo rat - nocturnal, large expandable cheeks, round tailed squirrel - hibernates
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arid skywalk grand canyon arizona
march 2004, david jin, $22 million, half revenue hualepai tribe, alcoholism problem, disneyfication, sacred land, lots of leakage, raises environmental awareness, unsustainable water supply, pressure of eastern areas
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arid phoenix arizona
cities grows, desert shrinks, npp reduced affects all food web, ground water use, fences - pronghorne antelope, swimming pools, offroading, agriculture - overgrazing, native cotton woods replaced by buffer grass - bush fires
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arid aral sea uzbekistan kazakhstan
90% water amu / syr darya, 2.9 to 7.2 million hectares irrigated areas, 43 million tonnes saline deposits in area, lake level down 16m lost 2/3rds volume, 40,000 tonne fishing industry gone, 80% irrigated area salinised, sea in 2, 10% size, kokora
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arid khushab salinity project jhelum river north pakistan
thar desert, 400mm ppt, 40 degrees, over irrigation salination, poverty - 8000 farming families, $69 million world bank 360km, under field drainage, surface drains, canals, education, 1/2 water logging 2 years, $46 to $194, 34% above poverty level
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arid great green wall north china
desertification affects 1/3rd land, 5 billion tonnes topsoil removed, 1 million km saline land, 1978, 350,000km shelterbelt by 2050, 130,000km so far, korain sandy lands - 40,000km = denmark, 300-500mm ppt, evap 3x higher, afforestation native poplar
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cold glacial polar climate
snow ice all year, cold dry, katabatic winds, latitude >66.6 NS, -60 icesheet, -10 coast, winter -70 to -25, summer -40 to -2
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cold periglacial climate
snow most not all year, high latitude or altitude, lose 1 degree every 100m climbed, low ppt, permafrost active layer, albedo effect 60% reflected, temps winter -50 summer +20
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cold mountain climate
free from snow ice, landforms still seen, >600mm ppt relief rainfall, thin air, cant hold much heat, windy - air channelled between stratosphere and troposphere
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cold glacier types
unconstrained: icesheet - greenland, icecap - vatnajokull iceland, constrained: valley - teton wyoming USA, piedmont - axel heiburg island canadian arctic, outlet - solheimajokull iceland
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cold glacier formation
snow 50kg/m, falls on rocks, compacted freeze thaw removes air, neve 830kg/m, forms ice 910kg/m, 25 year process alps, 200 greenland
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cold glacial system
budget - balance of inputs and outputs, mass balance = acc - ab, acc - snow and avalanches, ab - meltwater, sublimation, calving, acc - snow and avalanches, equilibrium line - acc = ab, above - acc zone, below - ab zone, snout = end
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cold glacial movement
basal slip - meltwater at base, internal deformation, ice crystals deform slide past eachother, 20m per day usually 100m per year, steeper slope, thicker ice, more meltwater = faster
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cold glacial erosion
abrasion - freeze thaw provides material, wears away at bedrock, plucking - meltwater refreezes with main body of glacier, rocks pulled off, dilation - pressure released when ice melts so rock expand, rotational movement - rock lip increases pressure
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cold glacial trough nant ffrancon valley north wales
500m valley floor, 850m high sides, V shaped valley interlocking spurs eroded - plucking and abrasion to U shaped valley truncated spurs, very deep misfit stream
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cold hanging valley bridal veil falls yosemite USA
188m drop, point where small glacial trough intersected by large, glacier erodes larger more, often waterfall
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cold ribbon lake windermere UK
1'5km wide, 18km long, 66m deep, carved by glacier, softer rock, forms basin, glacier retreats, fills with water
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cold corrie glaslyn wales
450m high backwall, 300m lake, plucking steepens back wall, abrasion deepens, snow collects in nivation hollow, turns to ice, mostly N facing slopes in N hemisphere - shaded, freeze thaw - abrasive material, rock lip causes rotational erosion
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cold arete crib goch wales
65m high backwalls, two corries form back to back, knife edge ridge
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cold pyramidal peak snowdon wales
1085m high, three glaciers formed back to back, forms peak, rare to have three glaciers in different directions
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cold glacial transportation
supraglacial - ontop, subglacial - underneath, englacial - within
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cold glacial deposition
change in speed or direction, ablation till - deposited in situ when reatreating, lodgement till - friction causing deposition whilst moving, glacial fluvial deposits - infront of glacier by meltwater
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cold glacial deposition characteristics
unstratified - no layers, unconsolidated - poorly bonded, unsorted - many shapes and sizes, unrounded - angular
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cold glacial moraines
terminal - cordillera huyhuash peru, lateral - vadret da tschierva switzerland, medial - breithorn zematt switzerland, recessional - steigletscher switzerland
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cold glacial deposition landforms
erratics - random deposits (lodgement till) bremgarten switzerland, drumlins - upper ribble valley yorkshire, 1km long. 500m wide, 50m high, egg shaped form under ice, stoss end = steep faces upstream, long axis in direction of flow
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cold weathering
freeze thaw - above glacier, water expands 9% when frozen, opens up weaknesses, blocks break off, carbonation - meltwater at base of glacier cold so holds more CO2 so acidic, reacts with limestone to form calcium bicarbonate, removed by solution
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cold talus / scree slopes craig lairig cairngorms scotland
10,000-20,000 years old, freeze thaw breaks rocks off, largest have most momentum so fall furthest, unrounded
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cold tors ben avon summit cairngorms scotland
10m high, irregular tightly spaced joints, vertical - cooling, horizontal - pressure release, granite weathered hydrolysis - H+ replace K+ rot, freeze thaw removes loose materials
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cold blockfields ben macdui cairngorms scotland
widely spaced joints ideal for freeze thaw, gentle slopes so boulders separate
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cold kettle holes solheimajokull outlet glacier iceland
15m diameter, ice blocks break off glacier, deposited, covered with sediment, melt leaving holes
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cold kames solheimajokull outlet glacier iceland
rounded hills stratified sorted sand and gravel immediately infront of glacier, meltwater exits and loses velocity dropping load, only maintained if glacier retreats quickly
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cold sandur / outwash plain vatnajokull icecap iceland
graded sand gravel clay, largest sediment closest to glacier - sorted, river action rounds particles, changes according to season
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cold esker blakeney norfolk england
3.5km long, 20m high, meltwater tunnels cut by subglacial rivers, sediment builds up during winter due to low velocity, accumulates over years, only preserved if glacier retreats rapidly
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cold net primary productivity
100-400g/year, 130mm ppt per year, frozen, short hydrological growing season, >6 degrees for one two months, short thermal growing season, water logging, acidic soils, nutrient bare, little bacteria activity, slow nutrient cycling, gelifluction
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cold plant adaptations
tundra - tree growth limited, no trees after 2000m high, deciduous to coniferous to shrubs, taiga - evergreen, needles, conical shaped, arctic moss - low slow growing, many leaves, bearberry - evergreen waxy hairy leaves, grow in nutrient bare soils
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cold animal adaptations
polar bear - hollow translucent fur, black skin, layer of fat, burrows under snow, females hibernate, arctic fox - small ears short legs, live young large litters, live underground, burrow into snow during blizzards
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cold alaska prudhoe bay
developed 1968, dry in 10 years, increases pressure to develop other areas, trans alaskan pipeline - 1300km, 12 pumping stations, $8 billion, 6m horizontal movement, 1.5m vertical, 3m above ground, oil heated to 80 degrees
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cold alaska oil exploration costs
isolated area, causes for environmental concern, only viable if price is high enough, 3 degree rise in temp caused 1 million km of permafrost melt, deeper active layer, faster coastal erosion at shishmaref, 25% worlds methane stored in permafrost
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cold ANWR development
last true wild frontier USA, 19.6 million acres, area 1002 - 1.5 million acres, dry winters, 3 biomes: wetlands, coastal plains, drier areas, low npp, 12-37mm ppt, 5 endemic mammals
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cold ANWR for
5000 jobs prudhoe bay, locals get $2000 and no taxes, 3-16 billion barrels oil, new infrastructure, better QOL, 41% in favour, inupiat tribe pro, provide oil security
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cold ANWR against
could be 6 month supply, caribou migration disrupted - breeding ground, effects unpredictable, 130,000 porquipine herd, no sensitive way to drill, bowhead whales feed inupiat, stop migration of polar bears, last 5% of coast, 52% oppose, gwichin tribe
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cold thermokarst iceland alaska canada
ice underground thaws, volume decreases, result of human activity - roads, houses - build on stilts, insulate pipes, use gravel - free draining but can lead to loss of marine life
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cold nepal
mountainous areas, isolated ecosystems, habitats compressed, high biodiversity, shallow soils, low npp, population 28 million, 40% below poverty line, 138/178 poorest, 80% mountainous, 3250 valley glaciers, 95 ecosystems, landslides mudflows common
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cold nepal tourism
1:4 more tourists than locals, undermine traditional values, inequality, 75kg wood per person per day removed = 3% forest ech year, illegal, everest = worlds highest junkyard, 25,000 visitors per year, cause trail erosion damage ecosystems
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cold nepal sherpas
tourism more lucrative farms trading, infrastructure - lukla airport, $2000 equipment, $5 per day, $60 high altitude, villages cant cope with influx, deforestation, yak dung fuel not fertiliser, cultural items sold, familes split, population down
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cold annapurna conservation project nepal
1986 protected, 7629km, WWF US government, forestation, sustainable water use, wildlife, use kerosene not wood, 120 plant species, S 3000mm ppt, N 500mm ppt, 40,000 locals sustained 55 villages, $7 per tourist, jobs - guard guides rescue, tourism
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cold antarctica
IAATO - <100 passengers on land at once, no closer than 5m to wildlife, arctic treaty - 1956, UN members sign up, demilitarised nuclear free, collaborative science, territorial claims suspended, environmental impact assesment
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cold antarctica tourism
26,000 visitors 2006 - $4000 each, penguins popular, no fear of humans, unspoilt, unique, pollution risk - fuel spills last low bacteria activity, MS explorer november 2004 S shetland, 154 passenger, 178m diesel leaked, 19 day tour $3500
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cold antarctica science
BAS labatory - isolated pristine, hole in ozone above discovered, impacts not considered first 30 years, lake vostok - underground lake, drilling could introduce bacteria and contaminate, EIA carried out, too risky = wont be done
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coasts waves
fetch - length wind blows over, swash - up beach, backwash - down, breaking - wave base slows down, angle too steep, breaks, constructive - strong swash weak backwash small well spaced, destructive - weak swash strong backwash tall closely spaced
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coasts tides
gravitational pull sun and moon, high low tides - suns position, spring tide - sun and moon on same side, pull water in same direction - high tide, neap tide - sun moon perpendicular low tides, storm surge - release of pressure on water, 1954 norfolk
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coasts marine erosion
hydraulic action - phneumatic pressure relased, air expands cracks open, abrasion - waves throws particles at cliffs, create notch, attrition - small particles erode each other, deposited or transported
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coasts sub aerial weathering
salt weathering - spray into joints, crystals grow, freeze thaw - water expands open up joints, carbonation - limestone chalk, CO2 in sea rain reacts creating CaCO2, biological - animals plant roots burrow into cliffs open up weaknesses
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coasts mass movement
driving forces must be >resisting forces, driving - act down slope eg gravity, resisting forces - can be equal but never bigger eg rock structure, water - act as lubricant
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coasts rock falls spain
rapid falling of rocks from cliff face, steep face, gravity, freeze thaw, many joints and bedding planes
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coasts rotational slumps flamborough head yorkshire
rock slides along plains, retain structure, undercut by sea
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coasts mudflows black ven dorset
steep slopes > 10 degrees, no vegetation, heavy rainfall saturates cliff, rapid movement, structure lost
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coasts bedding planes
seaward dipping - fairly steep, rock layers slip down plains, landward dipping - fairly steep, rock loosened by weathering and erosion, rock falls occur, horizontal - very steep cliffs, undercut by sea
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coasts rock lithology
physical and chemical make up, bonds within rocks, granite - strong, interlocking crystals
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coasts rock structure
weaknesses eg joints bedding plains faults folds, can have strong lithology and weak structure
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coasts cliff retreat per year
granite - 0cm, limestone and shale - 1cm, chalk - 1-100cm, glacial deposits - 1-10m
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coasts rock types
metamorphic - heat and pressure, very strong, igneous - cooled magma, intrusive underground large crystals stronger, extrusive overground small crystals weaker, sedimentary - eroded and recycled rocks, animal and plant matter, weaker
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coasts high resistance geology chalk cliffs selwicks bay flamborough head yorkshire
verticle chalk cliff, boulder clay ontop, 40m high, more removed than added, abrasion and hydraulic action, salt cyrstalisation and freeze thaw, slow retreat < 0.05m per year
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coasts low resistance geology boulder clay cliffs mappleton holderness coast yorkshire
15m high, low angle, rotational slump, biological weathering, marine erosion removes sediment, removal more than supply, 0.5m per year
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coasts wave cut platform selwicks bay flamborough head yorkshire
erosion forms notch between HWM and LWM, cliff unsupported collapses, leaves platform below LWM - erosion cant reach
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coasts microfeatures flamborough head yorkshire
vertical joints opened up due to high energy - wave refraction concentrated on headlands, crack to cave to arch to stack eg old harry dorset
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coasts concordant coastline lulworth cove, isle of purbeck east coast dorset
different geologies parallel to coastline, most resistant on outside, cove - chalk back wall, welden clay, portland limestone, glacial river - sea breaks through limestone, abrasion hydraulic action, lateral erosion welden clay - weak, chalk stronger
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coasts disconcordant coastline swanage bay isle of purbeck east coast dorset
different geologies perpendicular to coastline, headlands and bays, differential erosion, studland head - old harry chalk, headland made of more resistant chalk and clay, swanage bay preferentially eroded
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coasts sediment system
sediment from cliff and dune erosion and rivers, stored - dunes, beaches, offshore sandbanks, sediment cells - little movement between cells, sediment moved around within cells
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coasts transportation
long shore drift - swash in p wind direction, backwash straight down, sediment moved along, traction - large particles rolled along sea bed, suspension - small stones particles carried in sea, saltation - pebbles bounced along, solution - dissolved
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coasts deposition
sea loses velocity, material dropped, offshore deposits, beaches, more during summer - constructive waves, dynamic equilibrium summer and winter, more sediment = more deposition, human activity eg groynes, sheltered shallow areas = more
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coasts spit drift aligned hurst castle spit hampshire
long shore drift, bend in coastline, sediment deposited in solent, waves refract around forming recurve - sea too deep not enough sediment, 2km proximal to distal, 4 old recurves mark former locations before erosion, salt marsh redirects river avon
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coasts barrier beach swash aligned chesil beach dorset
30km long, fleet lagoon, tombolo and barrier beach - longest shingle beach in UK, barrier beach = corsses indentation in coastline, flint from flandrian transgression, sediment size increases left to right
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coasts sand vs shingle beaches southwold aldeburgh
aldeburgh - large shingle, steep gradient, higher angle of rest - 30 degrees, backwash less effective - permeable swash can perculate through so less energy, southwold - fine sand, shallow gradient
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coasts sea level change
eustatic - global sea levels due to climate change, flandrian transgression 6000 years ago rose 120m, steric effect, isostatic - land changes height, rebound after ice age, tectonic activity, emergent - features rise up, submergent - features sink
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coasts emergent raised beach kings caves isle of arran scotland
eustatic change, caves eroded, beach deposited, isostatic rebound land rose caves beach above HWM - no more erosion
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coasts submergent barrier beach chesil beach dorset
sea level picked up deposits, pushed up onto beach built up shingle
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coasts submergent flooded river valley lulworth cove dorset
concordant coastline, dry valley formed after ice age, sea level rose, water broke through gap
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coasts shoreline management plans
hold the line, no active intervention, advance the line, managed retreat, decided by DEFRA with natural england and councils, promontory effect - protected areas erode less than those around them, stick into sea disrupting sediment flow eg cromer
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coasts hard engineering
sea wall - vertical £3000/m £120/m/yr, curved £6000/m £60/m/yr, rip rap - £1250/m £10/m/yr, groynes - replaced every 25 yrs, £30,000/100m
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coasts soft engineering
beach replenishment - £80/m needs constant updating, importing sediment, no construction needed
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coasts managed retreat freiston shore lincolnshire
1983 66ha farmland claimed from sea, protected by embankment, £2.5 million maintain 50 years, £2 million managed retreat, embankment breached 3 times aug 2002, 66ha salt marsh - 2.5m halves wave energy, 15ha saline lagoon,
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coasts managed retreat freiston shore lincolnshire cont.
13 months 70% colonised 11 salt marsh plants, 8 fish, many birds, nature reserve 57,000 visitors, £150,000, 4 full time jobs, more habitats, stops coastal squeeze
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coasts north east norfolk
weak glacial deposits, marine erosion, saturated by rain - slumping, some areas below sea level - isostatic rebound - SE england sinking
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coasts no active intervention happisburgh norfolk
850 residents, low value, 1996 hold the line to NAI, 2025 - 100m lost caravan park 25 homes, 2055 - 10 homes lost, 2105 - 200m lost, 15 homes gone
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coasts hold the line sea palling norfolk
550 residents, 1996 hold the line, norfolk broads behind must be protected, £11 million 100,000 tonnes boulders offshore reefs, 2025 - beach replenishment, 2055 - sea wall repairs, 2105 - managed retreat
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coasts spains concrete coast malaga spain
minimal planning 1st 20 years, 90 golf courses, 200 planned, 700,000m water per year - enough for 25,000 town, marinas extended 2006, block LSD
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coasts sundarbans bay of bengal bangladesh
36 million residents coastal zone 137/177 HDI UN 2006, GDP/capita $1800, 44,500 tonnes fish 2003, shrimp 2nd biggest industry $500million, 86% farming output, mangrove forest largest 6000km, 60 of 70 species, 11,800kg fish per year, 20km lost/ yr
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coasts sundarbans bay of bengal bangladesh cont.
18 million tonnes pesticides used 2003 1/4 end up in rivers, river flow down 60% billions of tonnes of pollution every year
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coasts st lucia conflicts caribbean
fishing community 100 full time workers, soufriere marine management scheme: three years consultation, sustainability, four zones - marine reserves, fishing priority, yachting, multipurpose, £10/day docking free £4/ day diving
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coasts st lucia coral caribbean
2500g/m/yr - high NPP, symbiotic relationship coral and algae, fringed - around island - atoll - no island, barrier, between 30 degrees N and S, <60m deep, 22-25 degrees water temp. 88cm rise in next decade will smother
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Card 2

Front

hyper <30mm ppt, fog, 55 million years old, 50-120 by 1200km, SE p wind, ventifacts - abrasion, flat surfaces, desert pavement - deflation, layer of stones, yardangs - mega 20km long 1km wide 500m high between luderitz and mouth of orange river

Back

arid namib desert

Card 3

Front

4m wide can be 20m, salt crystallisation and carbonation

Back

Preview of the back of card 3

Card 4

Front

exogenous river, 1600m deep, 6 million year process, hydraulic action, abrasion

Back

Preview of the back of card 4

Card 5

Front

>25mm ppt per hour ephemeral river, much sediment, little infiltration inception, abrasion deepens 30m deep

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Preview of the back of card 5
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