Volcanic Hazards Primary and secondary hazards

Question 1

Although they are all unique, volcanic eruptions have common hazards

Answer 1

Primary (a direct result of the eruption)

Secondary (a result of the primary hazards)

Question 2

Primary Volcano Hazards

Answer 2

pyroclastic flows

lava flow

ash fall

gas eruptions

Question 3

Secondary Volcano Hazards

Answer 3

Lahars

Jokolhlaups

Question 4

What is pyroclastic flows

Answer 4

a mix of dense, hot, rock, ash and gasess which
move very quickly along the surface of the Earth. Due to their high speeds,
pyroclastic flows are extremely dangerous and can cause asphyxiation for anyone
unfortunately caught by the flow.

Question 5

Lava flow

Answer 5

most move slowly enough that they are not a risk to human life but can reach over 1000oC

When magma flows or erupts onto surface High temp or press in crust leaves it in liquid state

Question 6

Ash falls

Answer 6

Volcanic ash consists of tiny jagged particles of rock and natural glass blasted into the air by a volcano.

can travel many km, causing injuries, damage, deaths and disruption to transport

Question 7

Gas eruptions -

Answer 7

gases trapped in the magma are released during an eruption,sulphur dioxide they may form gas clouds which are hazardous to health

Question 8

Lahars

Answer 8

a mixture of rocks, mud and water which flow down the volcano. They are fast flowing and destroy everything in their path

These can occur when the heat of the eruption causes snow and ice to
melt or alternatively when an eruption coincides with heavy rainfall.

Question 9

Jökulhlaups -

Answer 9

floods caused by a sudden release of water and rocks when glacial ice is melted by the eruption