Geography- a
level
,Contents page
Tectonics- slide 3
Globalisation- slide 66
Coasts- slide 124
Diverse places- slide 190
Water cycle- 261
Carbon cycle- 322
Superpowers- 382
Health human rights and intervention- 434
,Geography- a
level
Tectonic hazards
, EQ1
Specification-
Key idea 1- the global distribution of tectonic hazards can be explained by plate boundary and other tectonic processes
Global distribution of causes of earthquakes, volcanoes, tsunamis
Distribution resulting from divergent, convergent, constructive plate movements
Causes of intraplate earthquakes
Key idea 2- there are theoretical frameworks that attempt to explain plate movements
Theory of plate tectonics + key elements (internal structure, mantle convection, palaeomagnetism, sea floor spreading, subduction, slab pull)
Operation of these processes at different margins
Physical processes impact on magnitude and type of eruption, earthquake magnitude and focal depth (Benioff)
Key idea 3- physical processes can explain the cause of tectonic hazards
P,S,L waves cause crustal fracturing, ground shaking, secondary hazards (liquefaction, landslides)
Volcanoes cause lava flows, pyroclastic flows, ash falls, gas eruptions and secondary (lahars, jokulhlaups)
Tsunamis are caused by submarine earthquakes at subduction zones as a result of sea-bed and water column displacement
, EQ2
Specification
Key idea 1- disaster occurrence can be explained by the relationship between hazards, vulnerability, resilience and disaster
Definition of a natural hazard and disaster, importance of vulnerability, communities threshold for resilience, hazard risk equation
Pressure and release model, complex inter-relationships between hazard and its wider complex
Social, economic impacts of tectonic hazards (volcanoes, earthquakes, tsunamis) on people, economy, environment of contrasting locations
Key idea 2- tectonic hazard profiles are important to an understanding of contrasting hazard impacts, vulnerability and resilience
Magnitude + intensity of tectonic hazards are measured using different scales (mercalli, moment magnitude scale, volcanic explosivity index)
Compare characteristics of Eq, Vo, Ts (magnitude, speed of onset, areal extent, duration, frequency, spatial predictability) through hazard profiles
Profiles of earthquakes, volcanoes, tsunami events- showing severity of social and economic impacts in LIC, NEEs
Key idea 3- development and governance are important in understanding disaster impact and vulnerability and resilience
Inequality of access to education, ousing, healthcare, income opportunities can influence vulnerability and resilience
Governance (local + national) and geographical factors (population density, isolation, urbanisation) influence vulnerability and a communities resilience
Contrasting hazard events in HIC, LIC, NEEs to show interaction of physical factors and significance of context in influencing the scale of disaster
, EQ 3
Specification
Key idea 1- understanding the complex trends and patterns for tectonic disasters helps explain differential impacts
Tectonic disaster trends since 1960 (no° deaths, no° effected, economic damage), overall disaster trends, accuracy and reliability of data to interpret
complex trends
Mega-disasters have regional + global significance (economic + human impacts)
Multi-hazard zone, linked hydrometeorological hazards contribute to a tectonic disaster
Key idea 2- theoretical framework can be used to understand prediction, impact and management
Prediction and forecasting, accuracy depend on type and location
Importance of different stages in hazard management cycle (response, recovery, mitigation, preparedness)
Parks model to compare response curve of hazard events- compare areas at different stages of development
Key idea 3- tectonic hazard impacts can be managed by a variety of mitigation and adaptation strategies which vary in effectiveness
Strategies to modify event include land-use zoning, hazard resistant design, engineering defences, diversion of lava flow)
Strategies to modify vulnerability and resilience include hitech monitoring, prediction, education, community preparedness and adaptation)
Strategies to modify loss include emergency, short and longer term aid insurance an actions of affected communities
,Enquiry Question 1
List:
why are some locations more at 1.1= causes of
tectonic hazards
risk from tectonic hazards 1.2= theoretical
frameworks
1.3= explaining
tectonic hazards
, EQ1- distribution 1.1a
Hazard- a threat to human life and property
Distribution- Tectonic hazards occur at plate boundaries as a result of them moving at different speeds and directions
They can occur on a plate boundary, in between plates (intra-plate) and in volcanic hotspots
Intraplate earthquake- occur inside plate margins due to stresses and pressures in the crust
Volcanic hotspots- due to a fracture in the crust, magma plume (areas of hot, upwelling mantle) in the mantle creates
the eruption- creates islands (e.g. Hawaii, Iceland)
Tectonic plate types-
Oceanic- 7-10km thick, heavier, high density
Continental-25-75km, lighter, less dense
, EQ1 - divergent plate
movements 1.1b (1.2a)
AKA constructive plate margin
Mantle convection forces plates apart-> tensional forces open cracks and faults between the 2 plates -> this
creates a pathway for the magma to move towards the surface
It creates earthquakes as the movement of the plates are not smooth or continuous, there is often friction due to
the rigid nature of the lithosphere, which then slip and create sudden movements. This results in shallow-focus
earthquakes which are low-moderate in magnitude.
Divergent-
oceanic to oceanic- rising convection currents bring magma to surface (result in small, basaltic eruptions)
creating a new oceanic plate (OCEAN RIDGES, VOLCANOES, EARTHQUAKES)
Continental to continental- geologically recent mantle plume splits a continental plate to create a new ocean
basin (RIFT VALLEY, VOLCANOES, EARTHQUAKES)
, EQ1 - Convergent plate
movement 1.1b (1.2a)
AKA destructive margin
Mantle convection pulls plates towards subduction zones whilst the other end of the plate is being pulled away -> the more dense oceanic plate is
subducted -> descending plate melts at depth (wet partial melting) -> generates magma with high gas, high silica content- explosive
More powerful
Convergent-
Oceanic to oceanic- one oceanic plate is subducted beneath the other due to having the slightly different densities, plate melts and magma
makes its way to the surface- magma cools in water creating an ocean arc (OCEAN TRENCH, ISLAND ARC, EARTHQUAKES, VOLCANOES)
Continent to continent- collision of two land masses, creates a mountain belt as land crumbles and forces its way upwards (FOLD
MOUNTAINS, EARTHQUAKES)
Oceanic to continent- oceanic plate is subducted under the continental plate- where it subducts creates an ocean trench, ocean crust melts
which creates more magma, creating more pressure which makes its way through weak spots (FOLD MOUNTAINS, EARTHQUAKES, VOLCANOES)
level
,Contents page
Tectonics- slide 3
Globalisation- slide 66
Coasts- slide 124
Diverse places- slide 190
Water cycle- 261
Carbon cycle- 322
Superpowers- 382
Health human rights and intervention- 434
,Geography- a
level
Tectonic hazards
, EQ1
Specification-
Key idea 1- the global distribution of tectonic hazards can be explained by plate boundary and other tectonic processes
Global distribution of causes of earthquakes, volcanoes, tsunamis
Distribution resulting from divergent, convergent, constructive plate movements
Causes of intraplate earthquakes
Key idea 2- there are theoretical frameworks that attempt to explain plate movements
Theory of plate tectonics + key elements (internal structure, mantle convection, palaeomagnetism, sea floor spreading, subduction, slab pull)
Operation of these processes at different margins
Physical processes impact on magnitude and type of eruption, earthquake magnitude and focal depth (Benioff)
Key idea 3- physical processes can explain the cause of tectonic hazards
P,S,L waves cause crustal fracturing, ground shaking, secondary hazards (liquefaction, landslides)
Volcanoes cause lava flows, pyroclastic flows, ash falls, gas eruptions and secondary (lahars, jokulhlaups)
Tsunamis are caused by submarine earthquakes at subduction zones as a result of sea-bed and water column displacement
, EQ2
Specification
Key idea 1- disaster occurrence can be explained by the relationship between hazards, vulnerability, resilience and disaster
Definition of a natural hazard and disaster, importance of vulnerability, communities threshold for resilience, hazard risk equation
Pressure and release model, complex inter-relationships between hazard and its wider complex
Social, economic impacts of tectonic hazards (volcanoes, earthquakes, tsunamis) on people, economy, environment of contrasting locations
Key idea 2- tectonic hazard profiles are important to an understanding of contrasting hazard impacts, vulnerability and resilience
Magnitude + intensity of tectonic hazards are measured using different scales (mercalli, moment magnitude scale, volcanic explosivity index)
Compare characteristics of Eq, Vo, Ts (magnitude, speed of onset, areal extent, duration, frequency, spatial predictability) through hazard profiles
Profiles of earthquakes, volcanoes, tsunami events- showing severity of social and economic impacts in LIC, NEEs
Key idea 3- development and governance are important in understanding disaster impact and vulnerability and resilience
Inequality of access to education, ousing, healthcare, income opportunities can influence vulnerability and resilience
Governance (local + national) and geographical factors (population density, isolation, urbanisation) influence vulnerability and a communities resilience
Contrasting hazard events in HIC, LIC, NEEs to show interaction of physical factors and significance of context in influencing the scale of disaster
, EQ 3
Specification
Key idea 1- understanding the complex trends and patterns for tectonic disasters helps explain differential impacts
Tectonic disaster trends since 1960 (no° deaths, no° effected, economic damage), overall disaster trends, accuracy and reliability of data to interpret
complex trends
Mega-disasters have regional + global significance (economic + human impacts)
Multi-hazard zone, linked hydrometeorological hazards contribute to a tectonic disaster
Key idea 2- theoretical framework can be used to understand prediction, impact and management
Prediction and forecasting, accuracy depend on type and location
Importance of different stages in hazard management cycle (response, recovery, mitigation, preparedness)
Parks model to compare response curve of hazard events- compare areas at different stages of development
Key idea 3- tectonic hazard impacts can be managed by a variety of mitigation and adaptation strategies which vary in effectiveness
Strategies to modify event include land-use zoning, hazard resistant design, engineering defences, diversion of lava flow)
Strategies to modify vulnerability and resilience include hitech monitoring, prediction, education, community preparedness and adaptation)
Strategies to modify loss include emergency, short and longer term aid insurance an actions of affected communities
,Enquiry Question 1
List:
why are some locations more at 1.1= causes of
tectonic hazards
risk from tectonic hazards 1.2= theoretical
frameworks
1.3= explaining
tectonic hazards
, EQ1- distribution 1.1a
Hazard- a threat to human life and property
Distribution- Tectonic hazards occur at plate boundaries as a result of them moving at different speeds and directions
They can occur on a plate boundary, in between plates (intra-plate) and in volcanic hotspots
Intraplate earthquake- occur inside plate margins due to stresses and pressures in the crust
Volcanic hotspots- due to a fracture in the crust, magma plume (areas of hot, upwelling mantle) in the mantle creates
the eruption- creates islands (e.g. Hawaii, Iceland)
Tectonic plate types-
Oceanic- 7-10km thick, heavier, high density
Continental-25-75km, lighter, less dense
, EQ1 - divergent plate
movements 1.1b (1.2a)
AKA constructive plate margin
Mantle convection forces plates apart-> tensional forces open cracks and faults between the 2 plates -> this
creates a pathway for the magma to move towards the surface
It creates earthquakes as the movement of the plates are not smooth or continuous, there is often friction due to
the rigid nature of the lithosphere, which then slip and create sudden movements. This results in shallow-focus
earthquakes which are low-moderate in magnitude.
Divergent-
oceanic to oceanic- rising convection currents bring magma to surface (result in small, basaltic eruptions)
creating a new oceanic plate (OCEAN RIDGES, VOLCANOES, EARTHQUAKES)
Continental to continental- geologically recent mantle plume splits a continental plate to create a new ocean
basin (RIFT VALLEY, VOLCANOES, EARTHQUAKES)
, EQ1 - Convergent plate
movement 1.1b (1.2a)
AKA destructive margin
Mantle convection pulls plates towards subduction zones whilst the other end of the plate is being pulled away -> the more dense oceanic plate is
subducted -> descending plate melts at depth (wet partial melting) -> generates magma with high gas, high silica content- explosive
More powerful
Convergent-
Oceanic to oceanic- one oceanic plate is subducted beneath the other due to having the slightly different densities, plate melts and magma
makes its way to the surface- magma cools in water creating an ocean arc (OCEAN TRENCH, ISLAND ARC, EARTHQUAKES, VOLCANOES)
Continent to continent- collision of two land masses, creates a mountain belt as land crumbles and forces its way upwards (FOLD
MOUNTAINS, EARTHQUAKES)
Oceanic to continent- oceanic plate is subducted under the continental plate- where it subducts creates an ocean trench, ocean crust melts
which creates more magma, creating more pressure which makes its way through weak spots (FOLD MOUNTAINS, EARTHQUAKES, VOLCANOES)
