Unit 1 : Topic 1 : World At Risk

Question 1

Hazard

Answer 1

A perceived natural event that has the potential to threaten both life and property.

Question 2

Disaster

Answer 2

A hazard becoming reality in an event that causes death and damage to goods/property and the environment.

Question 3

Geophysical

Answer 3

A hazard formed by tectonic/geological processes (earthquakes, volcanoes, tsunamis).

Question 4

Hydro-meterological

Answer 4

A hazard formed by hydrological (floods) and atmospheric (storms and droughts) processes.

Question 5

Risk

Answer 5

The probability of a hazard event occurring and creating loss of lives and livelihoods.

Question 6

Plate

Answer 6

Rigid, less dense ‘slabs’ of rock floating on the asthenosphere.

Question 7

Magma

Answer 7

Molten material that rises towards the Earth’s surface when hotspots within the asthenosphere generate convection currents.

Question 8

Lithosphere

Answer 8

The crust of the Earth, around 80-90km thick.

Question 9

Asthenosphere

Answer 9

A semi-molten zone of rock underlying the Earth’s crust.

Question 10

Conservative boundary

Answer 10

A boundary between plates where the movement of the plates is parallel to the plate margin and the plates slide past each other.

Question 11

Constructive boundary

Answer 11

A boundary between plates where the plates are diverging.

Question 12

Destructive boundary

Answer 12

A boundary between plates where the plates are converging.

Question 13

Island arc

Answer 13

A chain of volcanic islands resulting from subjecting lithospheric plates.

Question 14

Pyroclastic flow

Answer 14

A dense cloud of lava fragments thrown out by an erupting volcano as a result of bursting gas bubbles within the magma.

Question 15

Lahar

Answer 15

A flow of volcanic debris, either dry or mixed with water as a mudflow.

Question 16

Subduction

Answer 16

The zone where an oceanic plate descends back into the mantle.

Question 17

Fault line

Answer 17

A fractured surface in the Earth’s crust where rocks have travelled relative to each other.

Question 18

Greenhouse effect

Answer 18

The warming of the Earth’s atmosphere due to the trapping of heat that would otherwise be radiated back into space - it enables the survival of life on Earth.

Question 19

Enhanced greenhouse effect

Answer 19

This occurs when the levels of greenhouse gases in the atmosphere increase, owing to human activity.

Question 20

Milankovitch cycles

Answer 20

Theory developed by a Serbian scientist, arguing that the surface temperatures of the Earth change over time because of the Earth’s orbit, axis tilt and axis wobble.