Volcanoes

Question 1

What are the features of shield volcanoes

Answer 1

Gentle slopes and wide base
Frequent eruptions of basic lava
Lava flows at high speeds and long distances
Non violent eruptions
Non viscous lava because of basaltic compositions
Found at constructive boundaries

Question 2

What are the features of composite volcanoes

Answer 2

Steep sided with a cone shape
High with narrow base
Explosive eruptions of lava and ash
Layers of alternating ash and lava
Viscous lava builds in layers and doesn’t flow far
Found at destructive plate boundaries
Parasitic volcanoes formed when main vent is blocked

Question 3

What does more silica mean in lava

Answer 3

More silica = more viscous

Question 4

What does more silica mean in lava

Answer 4

More silica = more viscous

Question 5

Why does high viscosity cause explosive reactions

Answer 5

Gas in magma can’t escape easily causing violent eruptions

Question 6

What is the VEI

Answer 6

The volcanic explosivity index is a scale used to measure how intense a volcanic eruption is