Expert-level volcanology covering volcanic processes, eruption styles, volcano monitoring, volcanic hazards, igneous petrology, and volcanic contributions to climate.
Composition: basaltic (low silica, low viscosity) to rhyolitic (high silica, high viscosity). Viscosity: controls eruption style — low viscosity effusive, high viscosity explosive. Volatiles: H2O, CO2, SO2 dissolved in magma — exsolve during ascent driving eruption. Temperature: basalts 1100-1200 C, rhyolites 700-850 C.
Hawaiian: low viscosity lava, lava fountains and flows, low explosivity. Strombolian: intermittent explosions, scoria bombs, moderate explosivity. Vulcanian: discrete explosions, dense ash clouds, high explosivity. Plinian: sustained column 10-50 km high, pumice fallout, most explosive. VEI: volcanic explosivity index, 0-8 scale, logarithmic.
Lava flows: slow moving, destroys property, rarely kills. Pyroclastic flows: hot gas and ash, 200-700 C, 100-200 km/h — most deadly. Lahars: volcanic mudflows, can travel far from volcano along river valleys. Tephra fall: ash dispersal by wind, disrupts aviation, collapses roofs. Volcanic gases: SO2, CO2, H2S — hazardous in crater areas and low topography.
Seismicity: volcano-tectonic events, long-period events, tremor — precursors. Ground deformation: GPS, InSAR, tiltmeters — inflation signals magma intrusion. Gas monitoring: SO2 flux by DOAS, CO2/SO2 ratio for magma degassing depth. Thermal imaging: satellite MODIS and VIIRS, ground IR cameras.
| Pitfall | Fix |
|---|---|
| Single precursor as eruption predictor | Use multiparameter approach |
| Ignoring historical eruption record | Past behavior best guide to future activity |
| Confusing effusive and explosive hazards | Depends critically on magma composition and volatile content |
| Missing phreatomagmatic hazard | Water interaction can dramatically increase explosivity |