Physical case studies

Question 1

How did Borrowdale form?

Answer 1

2 million years of glacial and interglacial periods
tectonic movement - 2 major periods of mountain building - uplift and folding
discordant radial drainage pattern made across rock bands

Question 2

how did lakes and troughs form in Borrowdale?

Answer 2

originally u-shaped valley
ribbon lakes - BVGs eroded landscape

Question 3

how/where did corries form in Borrowdale?

Answer 3

BVGs - hilly and mountaneous area
south - lower and weaker ice movement - not high enough for corries
to form hard/resistant rock is needed - south would collapse

Question 4

how does altitude affect Borrowdale?

Answer 4

lower hills in north
higher in south
glacier moves from corries hills -> lower
weathering

Question 5

how does geology affect Borrowdale?

Answer 5

2 million years of glacial cycles
BVGs - resistant, hard, steep sloped, jagged profiles
north - Skiddaw slates - smoother, less resistant

Question 6

how does aspect affect Borrowdale?

Answer 6

corries in N
N-S orientation of ice
few corries formed e/w due to more solar isolation

Question 7

how does climate affect Borrowdale?

Answer 7

upland areas temperature is lower
wet and cold - more precipitation and snow
mechanical and chemical weathering

Question 8

how does relief affect Borrowdale?

Answer 8

hills created by BVGs - steep, cragged
west more smoothly sloping

Question 9

What are the flows of material in Borrowdale?

Answer 9

Rock/moraine moved along valley
weathering and mass movement
ice

Question 10

what are the flows of energy in Borrowdale?

Answer 10

1. meltwater - warming climate = more kinetic energy to move sediment (Derwent water filling up)
2. GPE higher up and decreases with ice/rock flow, ice on gradient = kinetic energy
3. thermal energy - ice melts and sediment is deposited

Question 11

Short-term changes in Borrowdale

Answer 11

mass movement - rockfall, slide, slump
material high up no longer there - changes valley - scree

Question 12

medium term changes in Borrowdale

Answer 12

seasonal/annual
1. large differences (+ve and -ve balances affect retreat and advance which affects deposition and transportation)
2. moraines - variation - more deep = -ve snout position changes

Question 13

long term changes to Borrowdale

Answer 13

interglacial and glacial periods
repeated periods of erosion = features

Question 14

what are the main erosional landforms in Borrowdale?

Answer 14

• glacial trough - Borrowdale valley
• corrie - the Combe
• ribbon lake - Derwent water
• hanging valley - Gillercomb
• high mountains - Great Gable - climate - temperature decrease, altitude increases snow - corries formed - nivation/accumulation
• Jaws of Borrowdale - local variation in rock resistance harder - less able to erode

Question 15

what are the main depositional landforms in Borrowdale?

Answer 15

• drumlins - Derwent water island/near Keswick
• recessional moraine (rothswaite)
• hummocky moraine - upper areas of trough/corries

Question 16

what is the different significance of depositional and erosional landforms?

Answer 16

Erosional - larger and more dramatic (valleys created by repeated periods of erosion. climate and geology influenced

Question 17

How does mass movement affect geomorphic processes?

Answer 17

slumps and slides - smoother slopes
rockfalls - steep relief

Question 18

how does weathering affect geomorphic processes?

Answer 18

frost shattering
freeze-thaw cycles
rock weakened when water expands so break - joints formed
deglaciation - pressure release - dilation

Question 19

how does glacial transport and deposition affect geomorphic processes?

Answer 19

climate change - repeated cycles - till deposited reworked over time
features today present from last glacier - either see last glacier or long term

Question 20

how does glacial erosion affect geomorphic processes?

Answer 20

glacial and interglacial periods - colder = more plucking and abrasion - repeated cycles - more prominent features
geology - hard resistant BVGs eroded by cycles, rocks will not collapse easily, some features do not remain
N-facing slopes - corries form, cold climate and erosion

Question 21

How are landforms in Borrowdale interrelated?

Answer 21

corries on N side (angle tarn) - ice formed N facing and glaciers flowed S–>N valleys - deeper, wider, steep sides
truncated spurs formed
ribbon lake - overdeepened valley
hanging valley - smaller troughs up steep river valleys/waterfalls
roche mountonees - floor of trough where glacier cannot erode as easily - wouldn’t exist without ice movement
Jaws of Borrowdale - valley narrowing due to more resistant rock - connects with depositional - drumlins where moraine deposited at snout - repeated = recessional - location die to direction of ice flow up valley
all connected due to their formation from glacial activity

Question 22

what is the location and profile of Alaska?

Answer 22

massive
above the Arctic circle
coastal and interior regions and mountain ranges
extreme climatic variability - wet maritime south to extreme cold north
periglacial

Question 23

why is human activity occuring in Alaska?

Answer 23

natural resources - diversity, 4th largest glaciated area, gold, minerals, 40% surface water, fisheries etc
nomadic lifestyle still present
WW2 - desired to be self-sufficient
Gulf war 1990-91 and oil price crisis
ANWR drilling

Question 24

what are the benefits of drilling in Alaska?

Answer 24

1973 protected NA hunting
univasive techniques being developed
jobs
$1000 bonus per Alaskan per year
reduces trade defecit

Question 25

what human activity has occured in Alaska?

Answer 25

20% US oil produced gold rush 2450km Alaskan highway - war 1959 depressed 2/3rd gov employees found largest oil field 1977 Trans-Alaskan pipeline completed 12.8bn barrels transported crisis = depression (single commodity income) Valdez harbour cities for workforce

Question 26

How much oil remains in Alaska?

Answer 26

3 billion barrels - depleted by end of decade

Question 27

how has human impact been minimised?

Answer 27

pipeline built on flexible stays for natural hazards and to allow migration and river movement underneath insulation of buildings and roads to prevent permafrost melting 12 stations

Question 28

what are the main flows of material in Alaska as a result of human activity?

Answer 28

1. gravel pads for construction - extracted from streams and beds as insulating layer for roads loss of gravel = alters rate of transportation and deposition downstream, equilibrium changes - more erosion - beds and banks change course groundwater levels fell by 1m in 2km radius from extraction site, aquifer Palmer groundwater fell 2. extraction of material from borrow pits - material removed for road/airstrip construction. holes in the ground formed - active layer removed, permafrost exposed. thermokarst rapid - stablises 10 years, subsidence - water table lowers

Question 29

what are the flows of energy in Alaska due to human activity?

Answer 29

1. release gas/burning of gas in drilling flaring - chemical energy --> heat/light release gas/energy carbon dioxide and methane contribute to enhanced greenhouse effect, terrestrial radiation trapped in lower atmosphere - snow cover is reduced locally, causing increased temperature and an increased active later = more veg = more disruption to permafrost 2. heat from buildings and infrastructure urban island heat - Barrow 2.2 degrees higher than surroundings - domestic buildings 9% fewer days of temperatures below zero (freeze-thaw)

Question 30

what are the 4 main impacts on Alaska's periglacial environment due to human activity?

Answer 30

1. deeper active layer, permafrost table drops, discontinuous and sporadic permafrost increase rapidly 2. patterned ground change - less freezing and thawing (less frost heave in summer) - fewer stones pushed up, patterns are not maintained mass movement by creep degrades domes 3. solifluction rate increases, active layer increases, lobes, stepped profile - soil slides 4. collapse of pingos - temperature rise = ice core thaws = ognip dome collapses rampart surrounding left

Question 31

what are the consequences of human activity on Alaksa?

Answer 31

1. formation of thermokarst - landscape dominated by surface depression due to thawing of ground ice. extensive areas of hummocky ground interspaced with waterlogged hollows - depressions fill with water to form lakes vegetation is removed - decreases insulation and more subsidence formed when barrow pits are dug movement vehicles - heat emissions, turn land up - expose land to surface, melting, veg destroyed 2. formation of alases - flat-floored, steep-sided depressions , widespread thawing of ground ice causes subsidence - can contain lakes several combine - alas valley

Question 32

key facts of the Amazon basin?

Answer 32

6 million km2 in south america high average temperatures (25-30 degrees) no seasonal variation high annual precipitation (>2000mm) seasonal variation but no dry season biodiverse - 1/4 of medicines 390bn trees - 20% carbon in biomass

Question 33

how does geology affect the water cycle in the Amazon?

Answer 33

two contrasting geologies large areas of impermeable - minimal storage/high run-off/limited throughflow/infiltration permeable porous rock (limestone) in west

Question 34

how does temperature affect the water cycle in the Amazon?

Answer 34

high temperature = high evapotranspiration, strong convection = high humidity, thunderstorm clouds and intense precipitation continuous cycle of water between land, trees and atmosphere

Question 35

how does relief affect the water cycle in the Amazon?

Answer 35

gentle, undulating relief helps store water in summer months causing water logging, more throughflow/run-off high run-off in west - steep catchments

Question 36

how does geology affect the carbon cycle in the Amazon?

Answer 36

contrasting geologies igneous/metamorphic little storage of carbon west - some limestone - significant short-term stores

Question 37

how does temperature affect the carbon cycle in the Amazon?

Answer 37

high temperature and sunlight = more photosynthesis high temperature, rainfall, sunlight stimulate NPP - 2500 g/m2/year, Amazonia 25% all NPP in terrestrial ecosystems promotes rapid decomposition

Question 38

how does biomass affect the carbon cycle in Amazon?

Answer 38

main carbon store absorbs 2.4bn tonnes carbon dioxide/year 60% trees, 40% roots/soil global sink

Question 39

short term changes in the amazon basin to the water/carbon cycle?

Answer 39

More vegetation in summer months - more evapotranspiration, more interception, larger biomass store, less runoff More vegetation in summer - more photosynthesis - less carbon in atmosphere

Question 40

short term changes in the tundra to the water and carbon cycle

Answer 40

In summer - active layer thaws and overland flow occurs - forms pools of water In winter - very limited plant growth so low biomass store Low temperatures mean slower decomposition

Question 41

long term changes in the tundra to the water and carbon cycles?

Answer 41

Temperatures rising over time - permafrost will melt and increase run-off and surface store Increase in vegetation if temperatures are rising year on year - more photosynthesis Warmer temps could encourage more life - more respiration?

Question 42

long term changes in the rainforest to the water and carbon cycle?

Answer 42

More co2 in atmosphere and then more evapotranspiration from plants - more likely to get acid rain - damaging/killing the rainforest - reduction in interception and erosion of soils - so more run-off Enhanced greenhouse effect means that there is more carbon in the atmosphere and so temperatures rise

Question 43

human management strategies in the tundra?

Answer 43

Paragraph 1: Technology Lateral drilling - better oil detection resources Lowers impact of damage to ground with fewer insertion sites Paragraph 2: Human adaptations Infrastructure built gravel pads to protect permafrost from melting Buildings and pipelines built on piles to allow cold air to circulate to stop melting and allows for migration of animals Refrigerated supports on Trans-Alaskan pipeline - insulates Paragraph 3: Changing legislation and attitudes Change in emphasis from destruction to protection Protests for protection Other reasons too - Melting - increasing subsidence and thermokarst - damages the buildings and infrastructure

Question 44

how does human activity affect the water cycle in the tundra?

Answer 44

Oil and gas exploitation has increased snow melting and so flooding becomes more likely Extensive wetlands in summer - increase evaporation and disrupt drainage networks Artificial lakes created by srip mining store water from creeks is extracted for local industry

Question 45

how does human activity affect the carbon cycle in the tundra?

Answer 45

Melting of permafrost - decreases carbon store, increases thickness of active layer - flows become more rapid = fast cycle speeds up Heat is directly diffused by humans - melting, dust deposition which darkens snow surface - absorbs more sunlight. Removal of vegetation means less insulation POSITIVE FEEDBACK - more CO2 and methane in atm = more melting May be able to overcome with vegetation growth

Question 46

how does human activity affect the water cycle in the rainforest?

Answer 46

Deforestation increases ground temperatures but reduces cloud formation so can lead to permanent climate change Reduction of water storage in trees, soils and geology and atmosphere Increased run-off Floods in porto velho - 68,000 evacuated and 60 killed

Question 47

How does human activity affect the carbon cycle in the rainforest?

Answer 47

Deforestation will reduce carbon in biomass and soil Trees replaced by crops still reduce carbon store Less decomposers in areas of deforestation so less carbon Slowing of the cycle

Question 48

how do physical factors affect the water cycle in the tundra?

Answer 48

geology: Low permeability - water cannot get in easily Crystalline hard rocks only add to low permeability temperature: Low temperatures keep water as permafrost Active layer thaws in summer - more overland flow etc. Little evapotranspiration relief: Gentle, undulating relief helps to store water during summer

Question 49

how do physical factors affect the carbon cycle in the tundra

Answer 49

geology: Most carbon locked in permafrost Little impact on carbon temperature: Slow photosynthesis and respiration Slow decomposition biomass: Loss of carbon in permafrost when it melts Small store due to limited water and sunlight

Question 50

how do physical factors affect the water cycle in the rainforest?

Answer 50

geology: Contrasting geologies Large parts of Amazon catchment impermeable - minimal storage and high run-off Porous limestone - store water and slow run-off temperature: More evapotranspiration in the summer Strong convection Water continually cycled relief: High run-off in steep catchment areas Extensive gentle lowlands help store water More throughflow

Question 51

how do physical factors affect the carbon cycle in the rainforest?

Answer 51

geology: 2 contrasting geologies Little storage of carbon in igneous and metamorphic rock Limestone outcrops are significant stores of carbon temperature: High temp and sun light means more photosynthesis Promotes rapid decomposition Biomass: Main carbon store Absorbs 2.4bn tons of carbon/year 60% trees 40% roots Global sink

Question 52

medium term changes in Minnesota

Answer 52

Lobes of ice advance and abrade striations on rock More steep hills in SE where less covered in ice Ice sheet erosion means no spectacular landforms are formed unlike in valley glaciers

Question 53

short term changes in Minnesota

Answer 53

Warren river drained Lake Agassiz Water overflowed and the drainage strategy helped form the mississippi river

Question 54

long term changes in Minnesota

Answer 54

Laurentide ice sheet is 1km thick and erodes mountains down 500-700m Creates ellipsoidal basin - now filled with lakes

Question 55

what are the main depositional landforms in Minnesota and how were they formed?

Answer 55

Till from each lobe is different as it originates at different places Wadena lobe Red, sandy till Formed Alexandria and Itasca moraine Created drumlins in Otter, Wadena and Todd countries Rainy and Superior lobe: Till strewn across NE, mixture of basalt, granite, red sandstone, slate and greenstone Des Moines lobe: Tan colour - as rich in clay Till more than 160m deep Repeated periods of deposition lead to erosional landforms Different till deposited creates different erosional landforms

Question 56

what are the main erosional landforms in Minnesota and how were they formed?

Answer 56

Ice sheet is 1 km thick Mountains were worn down 500-700m Creation of an ellipsoidal basin and thousands of lakes More erosion on the weak shale in the NE Less erosion in the SE - as not much ice cover Erosional landforms created through deposits of till and moraine

Question 57

what pro-glacial lake is important and what does this do to the landscape?

Answer 57

Ice sheet damned natural water drainage in the area Pro-glacial lakes formed largest lake - Lake Agassiz - 440 km 2 Glaciers blocked water drainage to the North Lakes developed to the South During melting - these lakes overflowed and created the Minnesota and River Valleys and fertile, rich soil now used for farming

Question 58

grande dixence key facts

Answer 58

Grande Dixence is a gravity dam that is located in the Val Des Dix in Southwest Switzerland It has 350km2 of catchment and 35 glaciers providing seasonal melt It was constructed in 1960 for hydroelectric power and stores 400 million m3 of water Local moraine was used in the construction Water flowed through dam - drives 4 power stations and powers 400,000 swiss homes Summer glacial meltwater is stored and used to generate energy to meet the high winter demand

Question 59

how has Grande dixence changed water flow?

Answer 59

Reduced water flow in Borgne river Leads to a higher concentration of pollutants at Les Haudere More meltwater than river water Meltwater more polluted - more melting

Question 60

how has Grande Dixence changed energy flows?

Answer 60

Water stored behind the dam creates lack of flow and loss of energy This leads to deposition of sediment behind the dam Deposited sediment gets flushed out periodically and creates high sediment concentrations at these times More moraine More glaciofluvial landforms - eskers and kames etc.

Question 61

how has Grande Dixence changed sediment flows?

Answer 61

Trapped sediment creates clearer water downstream Clearer water will flow faster and erode land and landforms faster and more impactfully