Hazards Flashcards
Hazard risk
The probability or chance that a natural hazard may take place
Natural hazard
A natural event that threatens people or has the potential to cause damage , destruction and death
Basaltic lava
Basaltic lava is another term for mafic lava. Maficlava is molten rock that is enriched in iron and magnesium and low in silica
Conservative plate margin
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
Fissure
A linear volcanic vent through which lava erupts, usually without any explosive activity
Hotspot
An area in the mantle from which heat rises as a thermal plume from deep in the earth
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, years after the event
Monitoring
Recording physical changes, such as earthquakes 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 signs
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 in 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 of improving building design
Secondary effects
The after effects that occur as indirect impacts of a natural event, sometimes in a longer timescale, for instance fires due to ruptured gas mains resulting from the ground shaking
Subglacial eruptions
A volcanic form produced by subglacial eruptions or eruptions beneath the surface of a glacier or ice sheet which is then melted into a lake by the rising lava
Tectonic hazard
A natural hazard caused by movement of tectonic plates
Tectonic plate
A rigid segment of the earth’s crust which can “float” across the heavier, semi molten rock below. Continental lattes are less dense, but thicker than oceanic plates.
Volcano
An opening in the earths crust from which lava ash and gases erupt
Volcanism
Volcanic activity or phenomena
