ESC volcanoes 2

Types of volcanoes

shield

cinder cone

composite (strato)

shield volcanoes

large,

form from successive flows of low-viscocity basaltic lava.

like a warriors shield, flatter near summit.

low explosiveness

not associated with death

composite volcano

steep slope by successive flow of lava; conical shape

cinder cone volcano

smallest

form loose pyroclastic fragments of vesicular basalt, and bombs from gassy magma

straight, steep sides (conical)

erode easily

types of eruptions classification

explosive

height of column

flood basalts

high volume of fluid lava from mantle flumes. flood.

repeated effusions produce layers of lavas to form plateaus

volcanic hazards

lava flow, gases, ashfall, pyroclastic flow, lahar, tsunami

ash falls

coats, abrasive, if acidic can lead to respiratory, engine or vegetation problems.

fumarole

vents that emit hot gases can be 1000degC

Gases/acid rain

CO2 and H2S invisible but can poison/choke people. dissovle in water droplets, lead to acid rain

pyroclastic flow

avalanche of hot gas/pyroclastic material

nuee ardente

glowing cloud, gas hot and turbulent

lahar

hot mud flow. extra bad when snow capped

lava flow

death, loss of property/vegetation

phreatic explosion

when magma touches water/ice

in subterranean volcanoes or island arc volcanoes

contact of magma/water during eruption

climate effects

caused by ash and gases.