physical paper Flashcards
exresidence time for carbon held in rocks
150 million years
how long is carbon stored for in fast carbon cycle
350 years
rate of transfer fast vs slow carbon cycle
10-1000 times faster in fast cycle
% of carbon stored in each store
atmosphere 0.5%
oceans 27%
fossil fuels/sedimentary rocks 70%
biomass 1.5%
where does 50% of carbon fixation by p/s take place
in the oceans (50GT of carbon is drawn up from atmosphere by biological pump every year0
% of global water stored in oceans
in polar ice/glaciers
97%
2%
amazon temperature
27C all year round (no seasonal variation)
amazon precipitation rate
2500mm/year
lowest monthly=60mm (driER but no dry season0
how much of amazon precipitation is recycled by evapotranspiration
50-60%
carbon storage per hectare in;
TRF
grassland
soya plantation
400tonnes
16.2t (25x less)
2.7t (150x less)
amazon NPP
2500g/m2/year
% of deforestation in amazon for cattle ranching
how much C released by this
80%
340m tonnes CO2 per year
how much rainforest carbon is stored in biomass
60%
carbon storage per hectare in soil of TRF
90-200 tonnes
when did madeira river flood?
increased discharge?
no of deaths?
April 2014
river reached record levels of 19.68m above normal
60 deaths
deforestation increases runoff by a factor of what
27
impact of TRF deforestation on regional precipitation
20% decline
how many tonnes of carbon locked in Amazon
100 billion
how many tonnes of CO2 does amazon absorb per year
2.4b tonnes
releases 1.7b tonnes through decomposition
temperature range in tundra
-28C to 4C (negative for 9 months0
precipitation annually in tundra
50-350mm annually (majority falls as snow)
majority falls in 3-4 month summer when temp >0C
NPP in tundra
200g/m2/year
carbon stored in tundra
1600T per hectare
5/6 of this in soil, and only 4-30 tonnesper hectare in biomass
estimated losses of CO2 and CH4 from permafrost
7 to 40m tonnes CO2
24000 to 114000 tonnes CH4
arctic warms how much faster than anywhere else in the world
3 times
CO2 released from fossil fuel combustion
10b tonnes
fossil fuel combustion has increased atmospheric ppm CO2 by how much
280 to 400 ppm
phytoplankton transfer how much C from atmosphere to deep ocean per year
10GT
London water table fell two much in 1965 due to over-exploitation
90m
in a glacial, how much does sea level fall
by 100-130m
in a glacial, how much of continental land mass is covered by ice
1/3
how much of global energy combustion is from fossil fuels
87%
china afforestation stats
1978
400,000km2 of trees by 2050
when was Kyoto protocol
1997-2012
wetlands occupy how much of earth’s land surface
contain how much of terrestrial carbon pool
6-9%
35%
how many sediment cells in England and Wales
11 (determined by topography and shape of land e.g. Land’s End)
what percentage of sediment comes from rivers in coastal landscapes
70-80%
direction of LSD in UK
N to S in NE
W to E in SW
example of a beach
Filey Bay Yorkshire
5 miles wide
spit example
Orford Ness East Anglia
onshore bars example
slapton sands Devon
4km long
tombolo examples
chesil beach Dorset(by spit extension)
st ninian’s, orkneys (wave refraction) 500m long
salt marsh example
Abel tasman, NZ
requirement for geo to form
fault must be 70 to 90 degrees to the coastline
geo example
huntsmans head, Pembroke, Wales
4m at narrowest, 40m at widest
example of cave/arch/stack/stump evolution
old Harrys rocks, near swanage
rate of erosion in:
chalk and limestone
lias and shale
0.1m/year
0.8m/year
fetch flamborough head
1500km
river at flamborough head
river Ask
robin hoods bay shore platform:
width
when formed
500m max
within last 6000 years
saltburn beach sediment levels
net increase of 9245m3 between 2008 and 2011
nile delta direction of LSD
west to east
nile delta dominant wind direction
from west/north west 55-60% of time
when was Azwan dam built
1964
nile delta erosion rates now
up to 148m/year
Rosetta mouth 24m/year
Damietta mouth 36m/year
nile delta expected sea level rise
by up to 90cm by 2100
(up to 60% loss of farmland)
size of gamsa sand dunes
30 km across, between the 2 lagoons
nile delta historic sediment supply
provided 120m tonnes from river
now virtually 0
describe eustatic change
last 18000 years= interglacial (gone from glacial to warm period)
120m s.l. rise on average so submerging landforms
causing massive input of sediment ‘rolled onshore’ by rising sea levels (flandrian transgression)
last 6000 years= stable temps & climate, which allowed progression of civilisation
width and depth of fjords
often over 1000m deep
not very wide 2-4km
examples of fjords
sognefjord in Norway
Milford sound in NZ
rias examples
kings bridge estuary on south Devon coast 6 miles long
1 mile wide near mouth at salcombe
2 large drowned tributaries extend from east side of ria
example shingle beach
chesil beach Dorset
29km long
advantages of using OS maps
has scale: can compare distances and measure
land use and land height are clearly displayed
spatially and proportionally accurate features
easy to read
‘layers’ of information
physical geo and human land use
disadvantages of using OS maps
no temporal change: displays an area in an instant: ‘snapshot’ so could be outdated
doesnt show seasonal variation in beach e.g. height and width
advantages of using aerial photos
visually easy to see land use (physical and human)
easy to understand and access
easy to do rephotography
disadvantages of using aerial photos
doesnt show scale, height (contours), tidal change
lack of labels/information: cannot necessarily tell what they are
no compass points
mine head sea wall height
0.6m
mine head prediction of coastal retreat
up to 100m in next 50-100m
mine head coastal protection cost
£13 million
pakiri historical background of sand mining
on 8 feb 1994, minister of conservation granted commercial sand extractors 5 coastal permits under the RMS to dredge sand from nearshore seabed at mangawhai and pakiri
permits allow a total of up to 165000m3 of sand to be taken annually for 10 years
cost of 1m3 of sand in NZ
$40 in 2000
how much sand is mined weekly in pakiri
1500 tonnes
overview of past/current sand mining in pakiri
nearshore sand dredging on the coastline has operated for over 70 years
between 1994 and 2004, 165000m3/year
mining ended at mangawhai in 2005, but has continued at pakiri
current rates= 75000m3/year until 2020
ratio of inputs to outputs at pakiri beach
1:5
when was pakiri storm and what were the impacts
1978
28m breach at base of mangawhai spit
2nd breach altered tidal currents causing sedimentation of mangawhais harbour so made shallower so community threatened by flooding
harbour dredged and groynes constructed on spit to restore some equilibrium
coastal retreat in future at pakiri
LT retreat by 2100 estimates at 35m
width of coastal zone susceptible to erosion is higher than any of the Auckland region’s other 123 beaches
depth of pakiri dredging
occurring at 8-10m depth (active sediment from here is usually moved by constructive waves onto beach)
if sed was taken from deeper (18-25m) it wouldn’t impact coastal system
amazon deforestation in past 50 years
20% of forest
example of marine terrace
San Clemente Island of the Channel Islands in southern California
raised beach example
Isle of Arran , Scotland
relict cliffs example
Wairau Valley, New Zealand
Secondary vs primary forest carbon storage
Primary stores double C per hectare
Beach replenishment minehead
80m wider
Minehead golf course future retreat
100m in next 50 years
Minehead is worth how much
£300 million
