Volcanic Hazards

Question 1

Lava flows

Answer 1

Streams of molton rock that pour from an erupting vent

Basaltic lava - Free flowing and runs for long distances

Acidic lava - thick and will not flow easily

It burns, bulldozes and buries infrastructure, vegetation and agricultural land

Question 2

Pyroclastic flows

Answer 2

Gas and tephra flows

Very hot

Speeds of 100 km/h

Co2 and monoxide, sulphur dioxide and chlorine escapes through fumaroles

Sulphur dioxide and water = acid rain = leads to weathering and pollution

Question 3

Gas emissions

Answer 3

Ejected to the atmosphere

Question 4

Tephra bombs

Answer 4

Volcanic bombs ejected into the atmosphere

Largest is 7.6 in diameter

Question 5

Ash bombs

Answer 5

Ejected to the atmosphere

Question 6

Lahars

Answer 6

Mud flow

Snow and ice melt during the eruption

Rock,ash and soil = mixed together and destroy anything in their path by flowing the valleys

Melting snow and ice are associated with volcanic eruptions - large water release ( seen in Iceland - Jokulhaulp)

Question 7

Flooding associated with the melting Ice

Answer 7

Look at lahars

Question 8

Tsunamis associated with explosive eruptions

Answer 8

Violent eruption of island volcano

Displace the ocean water

Travel 600 km/ hour

Giant sea wave can be generated by earthquakes

Wavelength = 100km

Height under 1m in open ocean and travel at speeds over 700km