AQA GCSE tectonic hazards

Conservative plate margin

Conservative plate margin

two plates sliding alongside each other, in the same or different directions

Constructive (transform) plate margin

tectonic plate margin where rising magma adds new material to plates that are diverging or moving apart

Continental crust

the low density, thick outer layer of Earth which forms our continents

Convection currents

circular movement of heat within Earth which drive the movement of tectonic plates

Destructive plate margin

tectonic plate margin where two plates are converging and oceanic plate is subducted - there could be violent earthquakes and explosive volcanoes

Earthquake

a sudden or violent movement within the Earth's crust followed by a series of shocks

Fold mountains

uplifted land that is crumpled by the collision of two plates

Ground deformation

changes in the shape of volcanoes which is closely monitored to predict eruptions

Hot spots

where the Earth's crust is thin so magma is able to break through the surface, forming volcanoes e.g. Hawaii

Immediate responses

reaction of people as the disaster happens and in the immediate aftermath i.e. to save lives

Landslide

the movement of rock, earth or debris down the slope of a hill

Lava

magma that has erupted from a volcano

Long-term responses

later reactions that occur in the weeks, months and years after the event i.e. to rebuild lives

Management strategies

techniques of controlling, responding to, or dealing with an event

Magma

molten rock beneath the Earth's surface

Mantle

a hot, dense layer of Earth found between the crust and core

Monitoring

recording physical changes, i.e. detecting heat and shape changes of volcanoes using remote sensing, to help forecast when and where a natural hazard might strike

Oceanic crust

the dense, thin outer layer of Earth that lies underneath the ocean

Plate margin

the border between two tectonic plates

Prediction

using historical evidence and monitoring, scientists can make predictions about when and where a hazard may happen

Primary effects

initial impact of a natural event on people and property, caused directly by it, i.e. the buildings collapsing following an earthquake

Protection

actions taken before a hazard strikes to reduce its impact, such as educating people or improving building design

Search and rescue

an immediate response to a disaster where people are removed from danger and aid is provided

Secondary effects

after-effects that occur as indirect impacts of a natural event, sometimes on a longer timescale, i.e. fires due to ruptured gas mains, resulting from the ground shaking

Seismicity

the frequency and distribution of earthquakes in a certain area, recorded by seismographs

Subduction

at a destructive margin, where the denser oceanic plate moves beneath the less dense continental plate

Tectonic hazard

natural hazard caused by the movement of tectonic plates (i.e. volcanoes and earthquakes)

Tsunami

huge waves caused by earthquakes

Tectonic plate

section of the Earth's crust about 100km thick