Terms For Earth Science Chapter 1 Activities 3 And 4 (Book 3)

Front 1

lava flows

Back 1

streams of molten rock that come from vents and fissures in the Earth's crust

Front 2

viscosity

Back 2

a fluid's resistance to flow or internal friction

Front 3

pyroclastic flows

Back 3

high-density mixtures of hot ash and rock fragments with hot gases

Front 4

lahar

Back 4

a wet, cement-like mixture of water, mud, and volcanic rock fragments that flows down the slopes of a volcano and its river valleys

Front 5

tephra

Back 5

the term for pieces of volcanic rock and lava that are ejected into the air

Front 6

volcanic bomb

Back 6

the largest type of tephra; larger than 64 mm in diameter

Front 7

lapilli

Back 7

the "middle-sized" type of tephra; generally between 2 and 64 mm in diameter

Front 8

ash

Back 8

the finest type of tephra; less than 2 mm in diameter

Front 9

Volcanic Explosivity Index (VEI)

Back 9

the percentage of pyroclastics among the total products of a volcanic eruption

Front 10

andesitic lava

Back 10

lava that has a higher silica content than basaltic lava; rarely flows beyond the base of the volcano

Front 11

dacitic and rhyolitic lava

Back 11

lava that has a higher silica content than andesitic lava

Front 12

Volcanic ash hazards

Back 12

-collapse the roofs of homes, factories and schools
-cause breathing problems in humans and animals
-damage automobile engines
-coat the leaves of plants, interfering with photosynthesis
-can damage aircraft
-can form lahars when soaked by rain

Front 13

eruption at Tambora, Indonesia

Back 13

this eruption had a VEI of 7. pyroclastic flows streamed down its slopes. a caldera formed when the surface collapsed into the magma chamber. the eruption triggered a tsunami, along with tephra fall and pyroclastic flows- killed 10,000 and 82,000 died from famine