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The Lithosphere of Earth Igneous Processes and Volcanic Activity 1. Why study? • • • • •

Thermal state Thermal history Composition of interior Geothermal / Hazards Comparative planetology

2. Volcanism and plate boundaries • Divergent - Continental breakup (Flood basalts) - Mid-ocean ridge • Convergent - Domes, flows, explosive, composite volcanoes • Intraplate Volcanism - Strombolian style - Hawaiian style

The Lithosphere of Earth - Volcanism




Volcanic Styles Plinian Activity

Strombolian Activity Spatter Cone

Hawaiian Activity

Produces turbulent, buoyant cloud, Rises to great heights

Cinder Cone Bubble Rise Rate > Magma Rise Rate

Dome Growth Brittle lid

Degasse s Fracture & Growth

Viscous gas-rich magma

Magma Rise Rate > Gas Rise Rate

Cloud collapses to pyroclastic flows

Atmosphere sucked in, heated Exit velocity high Low viscosity gas-clast mixture Pressure greatly exceeds atmospheric pressure

Geo5-Vol-Class Notes  
Geo5-Vol-Class Notes