inner core

crust

mantle

outer core

reverse fault

normal fault

strike-slip fault

thrust or reverse fault

normal fault

strike-slip fault

P Waves

push and pull motionfastest-moving wavestravel in straight pathmove through solid and liquid material

move in up-and-down zigzag patternmove more slowly than P wavescannot travel through liquid material

S Waves

P wave

S wave

Love wave

Rayleigh wave

Mercalli Richtermeasures magnitude

measures destructionbased on man’s observations

2.0 - 2.9

4.0 - 4.9

5.0 - 5.9

6.0 - 6.9

7.0 - 7.9

8.0 - 8.9

3.0 - 3.9

Richter Scale Effects

magma chamber

vent

lava

ash

sidevent

crater

ClassifyingVolcanoes

by shape

by type of eruption

by how often they erupt

by shape

cinder cone

shield

composite cone

hill-shaped with a bowl-like crater

upside-down-saucer-shaped

symmetrical, cone-shaped

shield volcano

cinder cone volcano

composite cone volcano

shield

cinder cone

composite cone

by how often they erupt

extinctdormant

active

active• has erupted during

recorded history• is expected to erupt

again

dormant• erupted in distant past• not expected to erupt

again

extinct• does not have a

recorded eruption• is not expected to

erupt

by type of eruption

PlinianPelean

Vulcanianavalanche of red-hot dust and

gases; pyroclastic flow

violent, loud explosion of lava, ashes, cinders,

and gases

most powerful eruption,

spewing lava, gas, and dust

into atmosphereHawaiian/

Strombolian

quiet, runny lava; little or no cinder, ash, or

steam