Last Minute Tectonics Revision:
EQ1: Why are some locations at risk from tectonic hazards?
• Theory of Plate tectonics and its key elements
• 1915 - similar rock types were found on opposite continents. Antartica was found to have
had some tropical plants, suggesting it was at one point, more north.
• WW1 - Sonar technology was developed and people began to notice that the ocean wasn’t
flat and it actually had mountains and trenches.
• 1919 - theory that convention currents exist in the mantle was proposed
• 1946 - ocean floor was mapped using sonar and it revealed mountains and ridges.
• 1960 - Hess and Dietz developed the theory of sea-floor spreading (this was the idea that
magma comes up through ridges, it then rapidly cools and creates new ocean floor. This
plate is the subducted.
• 1965 - Wilson proposes the idea that the Earth’s crust is made up of chunks of rock called
plates.
• 1983 - GPS is used to monitor the earth's movements
• Paleomagnetism is the process of magma striking the earths magnetic polarity when it
cools. Scientists can use it to determine how old parts of the earth are.
• The Benioff Zone
• This is an area of seismicity which corresponds with the plate being pulled down (slab pull)
in a subduction zone.
EQ2: Why do some tectonic hazards develop into disasters?
• Define a natural hazard and a disaster and what is Degg’s model?
• Natural hazard - a perceived natural/geophysical event which has the potential to threaten
both life and property
• Disaster - The realisation of a hazard when it causes a significant impact on a vulnerable
population. It’s a disaster when 10+ are killed OR when 100+ are affected.
• Degg’s model shows that the more vulnerable the population, the higher the risk of
disaster.
• Why do people remain exposed to hazards?
• unpredictability
• lack of alternatives
• changing levels of risk
• cost vs benefit
• russian roulette
• Understanding vulnerability and resilience
• Hazard Vulnerability - This is the capacity of a person or group to anticipate, cope with,
resist and recover from the effects of a natural hazard
• Hazard resilience - the ability to resist, absorb and recover from the effects of a hazard.
• How to increase and decrease resilience
Increase resilience Decrease resilience
pre-planning low doctor:patient ratio
emergency procedures rapid population growth
good communications an unrealistic perception of the hazard
an integrated infrastructure
• Hazard Risk equation
• Risk = hazard magnitude x vulnerability / capacity to of pop to cope.
• Knowledge of the disaster risk index
• The disaster risk index highlights two important thingsi) ageing populationsii) the
acceleration of risk in a work exposed to a rage of hazards
EQ1: Why are some locations at risk from tectonic hazards?
• Theory of Plate tectonics and its key elements
• 1915 - similar rock types were found on opposite continents. Antartica was found to have
had some tropical plants, suggesting it was at one point, more north.
• WW1 - Sonar technology was developed and people began to notice that the ocean wasn’t
flat and it actually had mountains and trenches.
• 1919 - theory that convention currents exist in the mantle was proposed
• 1946 - ocean floor was mapped using sonar and it revealed mountains and ridges.
• 1960 - Hess and Dietz developed the theory of sea-floor spreading (this was the idea that
magma comes up through ridges, it then rapidly cools and creates new ocean floor. This
plate is the subducted.
• 1965 - Wilson proposes the idea that the Earth’s crust is made up of chunks of rock called
plates.
• 1983 - GPS is used to monitor the earth's movements
• Paleomagnetism is the process of magma striking the earths magnetic polarity when it
cools. Scientists can use it to determine how old parts of the earth are.
• The Benioff Zone
• This is an area of seismicity which corresponds with the plate being pulled down (slab pull)
in a subduction zone.
EQ2: Why do some tectonic hazards develop into disasters?
• Define a natural hazard and a disaster and what is Degg’s model?
• Natural hazard - a perceived natural/geophysical event which has the potential to threaten
both life and property
• Disaster - The realisation of a hazard when it causes a significant impact on a vulnerable
population. It’s a disaster when 10+ are killed OR when 100+ are affected.
• Degg’s model shows that the more vulnerable the population, the higher the risk of
disaster.
• Why do people remain exposed to hazards?
• unpredictability
• lack of alternatives
• changing levels of risk
• cost vs benefit
• russian roulette
• Understanding vulnerability and resilience
• Hazard Vulnerability - This is the capacity of a person or group to anticipate, cope with,
resist and recover from the effects of a natural hazard
• Hazard resilience - the ability to resist, absorb and recover from the effects of a hazard.
• How to increase and decrease resilience
Increase resilience Decrease resilience
pre-planning low doctor:patient ratio
emergency procedures rapid population growth
good communications an unrealistic perception of the hazard
an integrated infrastructure
• Hazard Risk equation
• Risk = hazard magnitude x vulnerability / capacity to of pop to cope.
• Knowledge of the disaster risk index
• The disaster risk index highlights two important thingsi) ageing populationsii) the
acceleration of risk in a work exposed to a rage of hazards
