DRRR volcanic hazards (ppt ver)

volcano

• a rupture in the earth’s crust

• located along earth’s boundaries

magma

molten rock found within the earth

lava

molten rock released from the earth’s mantle

convergent plate

earth’s plates moves toward eachother

divergent plate

earth’s plates move away from each other

main vent

the channel magma travels through to reach earth’s surface

magma chamber

a storage location of molten rock below the ground

crater

the top of the volcano where magma erupts

composite volcano

• they have viscous lava that is acidic

• they erupt violently

• they have steep sides

• they are located on convergent plate boundaries

shield volcano

• the lava is runny and not acidic

• they have gentle sides

• they have less violent eruptions

• they are located on divergent plate boundaries

lava flow

a mass of magma that flows down the slope of the volcano at a rate of 3 Km per day or 45 km per hour

volcanic gases

• one of the basic components of magma or lava

• water vapor, carbon dioxide, sulfur dioxide, hydrogen sulfide etc.

pyroclastic flow

refers to hot, dry masses of fragmented volcanic materials that move along the slope and the ground surface at a speed greater than 60 Km per hour

this flows from a collapsed eruption column or lava done

are turbulent low-concentration density current gases, rock debris, water that move above the ground surface at high velocities

tephra falls

are showers of fine to coarse-grained volcanic materials and other airborne products of a volcanic eruption

<2 mm diameter - ash

2-64mm diameter - lapilli

>64mm diameter - blocks and bombs

ballistic projectiles

are rocks that are released into the air by an erupting volcano

these land between 2 Km of the vent but cant travel as far as 5 Km or further if the eruption is very explosive

lahar

is a flowing mixture of volcanic debris and water

primary lahar or hot lahar - associated directly with volcanic eruption

secondary or cold lahar - caused by heavy rainfall

volcanic debris avalanche

landslides that occur in volcanic slopes; they are faster and deposits are more far-reaching compared to non-volcanic landslides