1. 4 VOLCANOES

Question 1

pyroclastic flows?

Answer 1

-frothing of molten magma in vent of volcano
-bubbles burst explosively to eject hot gases and pyroclastic material such as ash, glass shards and crystals
-clouds can be up to 1000 degrees

Question 2

tephra?

Answer 2

-eject matieral such as rock fragements into atmosphere
-can vary in size
-the ash and larger materials can cause buildings roofs to collapse and start fires
-dust can reduce visibility

Question 3

lava flows?

Answer 3

-secondary hazard
-streams of molten rock
-viscosity is determined by amount of silicon dioxide it contains
-some can reach 15m/s

Question 4

volcanic gases?

Answer 4

-associated with explosive eruptions and lava flows
-includes water vapour, sulfur dioxide, hydrogen, carbon monxide