AQA Geography A-level Hazards Flashcards

A comprehensive set of vocabulary flashcards covering the concept of hazards, human responses, plate tectonics, seismic events, tropical storms, and wildfires based on AQA Geography A-level notes.

Hazard

A potential threat to human life and property caused by an event.

Disaster

The occurrence when a vulnerable population that will be significantly disrupted and damaged is exposed to a hazard.

Degg’s model

A representation of the concept that a disaster occurs when a hazard meets a vulnerable population; if the population is not vulnerable, the event is not disastrous.

Geophysical hazard

Hazards caused by land processes, majorly tectonic plates, such as volcanoes.

Atmospheric hazard

Hazards caused by atmospheric processes and the conditions created by weather systems, such as wildfires.

Hydrological hazard

Hazards caused by water bodies and movement, such as floods.

Hydrometeorological hazards

Hazards that are both atmospheric and hydrological in nature, such as tropical storms.

Fatalism

A passive response to hazards based on the viewpoint that they are uncontrollable natural events and losses should be accepted as nothing can be done.

Risk sharing

A form of community preparedness where a community invests collectively, such as through insurance, to mitigate the impacts of future hazards.

Incidence

The frequency of a hazard, or how often it occurs, which is not affected by the strength of the hazard.

Magnitude

The size of a hazard, usually represented by a definable number that does not change regardless of location.

Intensity

The power of a hazard based on its effects on a person, which can change depending on management strategies or distance from the event.

Park Model

A graphical representation of human responses to hazards showing the steps of recovery (Relief, Rehabilitation, and Reconstruction) and the quality of life over time.

Asthenosphere

The semi-molten top layer of the mantle that moves due to convection currents and supports the lithosphere.

Lithosphere

The layer of the Earth broken up into tectonic plates, consisting of the crust and the very top of the mantle.

Continental crust

The less dense part of the Earth's crust that is not destroyed by plate movement.

Oceanic crust

The dense part of the Earth's crust that is destroyed by plate movement.

Paleomagnetism

The study of rocks that show the magnetic fields of the Earth; symmetrical bands of alternating magnetic polarity on the ocean floor provide evidence of sea floor spreading.

Ridge push

A force at constructive boundaries where gravity acts upon the ridge elevation to push plates further away, also known as gravitational sliding.

Slab pull

A force at destructive boundaries where a subducting plate sinking into the mantle pulls the rest of the plate (the slab) with it.

Hotspots

Areas of volcanic activity not related to plate boundaries, caused by hot magma plumes rising from the mantle and burning through the crust.

Lahars

Volcanic mudflows usually caused by melting ice at high latitudes.

Jökulhlaups

Glacial floods caused when high temperatures from magma quickly melt glaciers or ice sheets.

Nuées ardentes

Also known as pyroclastic flows; clouds of burning hot ash and gas that collapse down a volcano at high speeds.

Volcanic Explosivity Index (VEI)

A logarithmic scale from $VEI\,2$ onwards used to measure the power and explosiveness of volcanic eruptions.

Richter Scale

A logarithmic scale used to measure the strength of seismic waves.

Modified Mercalli Intensity Scale

A subjective scale ranging from $1$ to $12$ ($XII$) that measures the degree of destruction caused by a seismic event.

Liquefaction

A process where saturated soil acts like a liquid due to earthquake vibrations, causing buildings to subside.

Coriolis Effect

The effect of the Earth's rotation on weather events, which causes tropical storms to spin and prevents them from forming at the equator.

Saffir-Simpson Scale

A scale from $1$ to $5$ used to measure the magnitude of a tropical storm based on wind speed.

Storm surge

A high wave of sea water released onto a coast caused by the low pressure and high winds of a tropical storm system.

Crown fires

The most dangerous and destructive type of wildfire that burns the entire tree from bottom to top.

Surface fires

Wildfires that only burn leaf litter and are relatively easy to extinguish.

Ground fires

Slow-moving fires that burn dry peat or vegetation beneath the surface and can continue for a long time.