Key concepts Flashcards
Define primordial heat
The heat left over from the creation of the earth.
Define slab pull
The force generated by the denser oceanic crust gravitationally orientating itself deeper into the mantle.
Define ridge push
Magma rises as the plates move apart. The magma cools to form new plate material. It becomes denser and slides down away from the ridge causing other plates to move away from each other.
Define adaptation
The attempts by people or communities to live with hazard events. By adjusting their living conditions, people are able to reduce their levels of vulnerability.
Define fatalism
A view of a hazard event that suggests that people cannot influence or shape the outcome, therefore nothing can be dine to mitigate against it. They believe the outcome of an event is ‘Gods will’ and don’t put in preventative measures.
Define natural hazards
Events which are perceived to be a threat to people, the built environment and the natural environment. They occur in the physical environments of the atmosphere, lithosphere and the hydrosphere.
Define perception
The way an individual or a group views the threat of a hazard event. This will determine the course of action taken by individuals or the response they expect from governments and other organisations.
Define community preparedness / risk sharing
Prearranged measures that aim to reduce the loss of life and property damage through public education and awareness programmes, evacuation procedures, the provision off emergency medical, food and shelter supplies and the taking out of insurance.
Define frequency
The distribution of a hazard through time.
Define integrated risk management
The process of considering the social, economic and political factors involved in risk analysis; determining the acceptability of damage/disruption; deciding on the action to be taken to minimise damage/disruption.
Define magnitude
The assessment of the size of the impacts of a hazard event.
Define prediction
The ability to give warnings so that action can be taken to reduce the impact of hazard events. Improved monitoring, information and communications technology have meant that predicting hazards and issuing warnings have become more important in recent years.
Define primary effects
The effects of a hazard event that result directly from that event.
Define resilience
The sustained ability of individuals or communities to be able to utilise available resources to respond tom withstand and recover from the effects of natural hazard events.
Define secondary effects
The effects that result from the primary impact t of the hazard event.
Define protection
The aim to protect people, their possessions and the built environment from the impact of the event. Involves modifications to the built environment such as improved sea walls and earthquake proof buildings.
Define prevention
The intention to completely avoid potential adverse impacts of hazardous events.
What is radiogenic heat?
The radioactive decay of isotopes.
What is lava?
Molten rock flowing onto the surface. Acid lava solidifies very quickly, bust basic lava tends to flows some distance before solidifying.
What is the lithosphere?
The layer of the Earth which consists of the crust and the upper section ofthe mantle. It is this layer which is split into a number of tectonic plates.
Define an earthquake
As the crust of the earth is constantly moving, there tends to be a slow build up of stress within the rocks. When this pressure is released, parts of the surface experience, for a short period of time, an intense shaking motion. This is an earthquake.
What is retrofitting?
In earthquake-prone areas buildings and other structures can be fitted with devices such as shock absorbers and cross-bracing to make them more earthquake proof.
Define mitigation?
Mitigation strategy is designed to reduce or eliminate risks to people and property from natural hazards. Money spent prior to a hazardous event to reduce the impact of it can result in substantial savings in life and property following the event.
Does ridge push occur at a constructive or destructive plate boundary?
Constructive
Does slab pull occur at a destructive or constructive plate boundary?
Destructive
