SCIENCE CHAPTER 9 VOLCANISM

volcanic materials and hazards

A STREAM LIKE FLOW OF INCANDESCENT, MOLTEN ROCK MATERIALS ERUPTED FROM A VOLCANO.

TYPES OF VOLCANIC ERUPTION

a weak to violent eruption characterized by lava fountain and outburst of molten lava

• strombolian

• volcanian

• pelean

• plinian

TYPES OF VOLCANIC ERUPTION

a violent explosion characterized by voluminous ejections of pumice and by ash flows, results in the formation of caldera or volcano-tectonic depressions

• plinian

• pelean

• phreatomagmatic

• phreatic

TYPES OF VOLCANIC ERUPTION

highly viscous or solid lava blown into fragments and dust

• PHREATIC

• STROMBOLIAN

• PHREATOMAGMATIC

• VOLCANIAN

TYPES OF VOLCANIC ERUPTION

results from an ejection of magmatic gases and steam produced by the conversion of groundwater to steam by ascending magma

• plinian

• phreatomagmatic

• pelean

• strombolian

volcanic materials and hazards

A SHOWER OF FINE-TO-COARSE-GRAINED VOLCANIC MATERIALS AND OTHER AIRBORNED PRODUCT OF AN ERUPTION

TYPES OF VOLCANIC ERUPTION

an explosion driven by steam produced when ground water is heated due to an underlying heat source

• strombolian

• volcanian

• phreatic

• phreatomagmatic

TYPES OF VOLCANOES

built from ejected lava fragments, these are small and formed near or inside large volcanoes, and frequently occur in groups

• cinder cone volcanoes

• shield volcanoes

• composite volcanoes

TYPES OF VOLCANIC ERUPTION

a gas rich, pasty lava accumulates to form a dome on the volcano

• phreatomagmatic

• phreatic

• plinian

• pelean

TYPES OF MAGMA

least silica content

least viscosity

least tendency to form pyroclastic materials

highest tendency to form lava

• granitic magma

• basaltic magma

• andesitic magma