Volcanoes + Earthquakes Flashcards
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.
Volcano
An opening in the Earth’s crust from which lava, ash and gases erupt.
Plate margin
The margin or boundary between two tectonic plates.
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.
Tectonic hazard
A natural hazard caused by movement of tectonic plates (including volcanoes and 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.
Secondary effect
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.
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.
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.
Monitoring
Recording physical changes, such as earthquake tremors around a volcano, to help forecast when and where a natural hazard might strike.
