Hazard Effects: Geography AQA: GCSE (9:1)

Primary effects

The initial impact of a natural event on people and property, caused directly by it.

Secondary effects

The indirect effects of a natural event.

Lava flows

Molten rock that flows over the ground

Pyroclastic flows

Scalding avalanche of ash and hot, toxic expanding gas, traveling very fast down the flank of a volcano

Ash fall

The deposition of a layer of fine airborne rock and glass that have been erupted from a volcano

Gas (steam)

Toxic fumes and superheated water emitted from a volcano before and during an eruption

Acid Rain

Rain containing nitric and sulfuric acids

Shaking ground

During energy release, seismic waves vibrate solid ground

Liquefaction

The process by which an earthquake's violent movement suddenly turns loose soil into liquid mud

Tsunami

A giant wave usually caused by an earthquake beneath the ocean floor.

Fire

A hazard triggered when broken gas pipes are ignited by electricity sparks, or when gas stoves are toppled over.

Lahars

A destructive mudflow on the slopes of a volcano.

Infrastructure collapse

Seismic shockwaves cause buildings to twist and vibrate which can lead to them falling down, including bridges, roads, ports and railways

Casualties and deaths

Impact on people who are injured or fatally wounded due to building collapse, fire, tsunami etc