Volcanic Explosivity Index & Hazards

identifying volcanoes: shield

low viscosity, low volatiles, large volume, low slope angle

identifying volcanoes: strato

med-high viscosity, med-high volatiles, large volume, great slope angles

identifying volcanoes: caldera

large mass blown up (crater)

least to most explosive volcanoes

shield, flood basalt, strato, caldera

eruption types: icelandic

low viscosity, low volatiles, low explosivity index

eruption types: hawaiian

same as icelandic

eruption types: strombolian

moderate viscosity, moderate volatiles, medium explosivity index

eruption types: vulcanian

high viscosity, high volatiles, high explosivity index

eruption types: plinian

high viscosity, high volatiles, very high explosivity index

criteria to differentiate eruption styles

fragmentation of glass and minerals, dispersal plume, height of column erupting

hazards associated with volcanic eruptions

pollution of groundwater, bombs from eruptions landing, lava domes and their collapses, pyroclastic flows, mudflows, lava flows, acid rain, ash fall, lightning, gases, tsunamis

deadliest hazard associated with volcanoes?

pyroclastic flows

predicting volcanic eruptions

Bulging of the volcano, increase in seismic activity, increase in gas emissions, edifices, water content, gas composition, steam temperature

volcanic explosivity index

a scale for reporting the size of an explosive volcanic eruption