Impacts of volcanic hazards

What are some primary effects of volcanic eruptions

• Tephra

• Pyroclastic flows

• Lava flows

• Volcanic gases

What is tephra

Solid material ash, volcanic bombs and lapilli. Ejected from volcano and can be blown around Earth.

What are pyroclastic flows (nuees ardentes)

Very hot gas. High velocity flows made up of mixture of gas and tephra. Can reach up to speeds of 700km/h

What are lava flows

Low velocity, often unstoppable. Destroy crops, buildings and block roads. Don’t usually cause injury.

What are volcanic gases

Carbon dioxide, carbon monoxide, hydrogen sulphide, Sulphur dioxide and chlorine

What are some secondary effects of volcanic eruptions

• Lahars

• Flooding

• Volcanic landslides

• Tsunamis

• Acid rain

What are lahars (volcanic mudflows)

Unconsolidated ash combined with water may be swept down river valley in form of hot, dense fast flowing moving mudflow

What is flooding (in terms of volcanic eruption)

Eruptions may melt glaciers and ice caps serious flooding can result

What are volcanic landslides

High velocity and great momentum can cross between valleys and run up slopes causing rock and volcanic material to slide down volcano

What are tsunamis

Sea waves generated by violent volcanic eruption

What is acid rain

Volcanic gases combine with atmospheric moisture and acid rain forms as a result