Natural Hazards Flashcards
Hazard risk
The probability or chance that a natural hazard may take place.
Natural hazard
A natural event (for example an earthquake, volcanic eruption, tropical storm, flood) that threatens people or has the potential to cause damage, destruction and death.
Conservative plate margins
Tectonic plate margin where two tectonic plates slide past each other.
Constructive plate margin
Tectonic plate margin where rising magma adds new material to plates that are diverging or moving apart.
Destructive plate margin
Tectonic plate margin where two plates are converging or coming together and oceanic plate is subducted. It can be associated with violent earthquakes and explosive volcanoes.
Earthquake
A sudden or violent movement within the Earth’s crust followed by a series of shocks.
Immediate responses
The reaction of people as the disaster happens and in the immediate aftermath.
Long-term responses
Later reactions that occur in the weeks, months and years after the event.
Monitoring
Recording physical changes, such as earthquake tremors around a volcano, to help forecast when and where a natural hazard might strike.
Plate margin
The margin or boundary between two tectonic plates.
Planning
Actions taken to enable communities to respond to, and recover from, natural disasters, through measures such as emergency evacuation plans, information management, communications and warning systems.
Prediction
Attempts to forecast when and where a natural hazard will strike, based on current knowledge. This can be done to some extent for volcanic eruptions (and tropical storms), but less reliably for earthquakes.
Primary effects
The initial impact of a natural event on people and property, caused directly by it, for instance the ground buildings collapsing following an earthquake.
Protection
Actions taken before a hazard strikes to reduce its impact, such as educating people or improving building design.
Secondary effects
The after-effects that occur as indirect impacts of a natural event, sometimes on a longer timescale, for instance fires due to ruptured gas mains resulting from the ground shaking.
Tectonic hazard
A natural hazard caused by movement of tectonic plates (including volcanoes and earthquakes).
Tectonic plate
A rigid segment of the Earth’s crust which can ‘float’ across the heavier, semi- molten rock below. Continental plates are less dense, but thicker than oceanic plates.
Volcano
An opening in the Earth’s crust from which lava, ash and gases erupt.
Adaptation
Actions taken to adjust to natural events such as climate change, to reduce potential damage, limit the impacts, take advantage of opportunities, or cope with the consequences.
Climate change
A long-term change in the earth’s climate, especially a change due to an increase in the average atmospheric temperature.
Mitigation
Action taken to reduce or eliminate the long-term risk to human life and property from natural hazards, such as building earthquake-proof buildings or making international agreements about carbon reduction targets.
Orbital changes
Changes in the pathway of the Earth around the Sun.
Quaternary period
The period of geological time from about 2.6 million years ago to the present. It is characterized by the appearance and development of humans and includes the Pleistocene and Holocene Epochs.
Economic impact
The effect of an event on the wealth of an area or community
Environmental impact
The effect of an event on the landscape and ecology of the surrounding area.
Extreme weather
This is when a weather event is significantly different from the average or usual weather pattern, and is especially severe or unseasonal. This may take place over one day or a period of time. A severe snow blizzard or heat wave are two examples of extreme weather in the UK.
Global atmospheric circulation
The worldwide system of winds, which transports heat from tropical to polar latitudes. In each hemisphere, air also circulates through the entire depth of the troposphere which extends up to 15 km.
Immediate responses
The reaction of people as the disaster happens and in the immediate aftermath.
Long-term responses
Later reactions that occur in the weeks, months and years after the event.
Management strategies
Techniques of controlling, responding to, or dealing with an event.
Monitoring
Recording physical changes, such as tracking a tropical storm by satellite, to help forecast when and where a natural hazard might strike.
Secondary effects
The after-effects that occur as indirect impacts of a natural event, sometimes on a longer timescale, for instance impact on access to potable water can lead to spread of disease.
Social impact
The effect of an event on the lives of people or community.
Tropical storm (hurricane, cyclone, typhoon)
An area of low pressure with winds moving in a spiral around the calm central point called the eye of the storm. Winds are powerful and rainfall is heavy.
