Explosiveness of an Eruption
Low
High
Runny
Travels Faster
Shield Volcanoes
Thick
Travels Slower
Composite Volcanooes
Less Silica
<50% Silica = Basaltic Magma
Low Gas > Effusive Content
Hotter
More Silica
70% > *Rhyolitc Lava
Traps Gas Bubbles > Explosive
Cooler
Sometimes blocks vent > Pressure > More explosive
Magma = Silica + Oxygen > Viscosity
Medium Sized Eruptions
60% Silica = Andesite