layers'defined'by' composition'...
TRANSCRIPT
! Layers'defined'by'composition'
! Crust'! Thin,'rocky'outer'layer'of'Earth'
! Either'oceanic'crust'or'continental'crust'
! Oceanic'crust'is'7'km'thick'
! Mantle''
! 82%.of.the.Earth’s.volume.! Solid.rock.at.the.top,.liquid.at.the.bottom.
! Core'! Composed.of.ironBnickel.alloy.
! Extreme.pressure.found.in.the.center.of.the.core.
! Lithosphere.! The.crust.and.uppermost.mantle.
! Cool,.rigid.shell.! 100.km.thick.
! Asthenosphere.! Soft,.comparatively.weak.layer.! Below.the.lithosphere.! Rock.close.to.melting.
! Outer.Core.! Liquid.layer.2260.km.thick.! Metallic.iron.generates.Earth’s.magnetic.field.
! Inner.Core.! Solid.layer.having.a.radius.of.1220.km.
! High.temperatures.and.high.pressure.
! Nickel.mostly.
• Vibration.of.Earth.produced.by.a.sudden.release.of.energy.
• Movements.along.the.fault.line..
• Focus.–.point.within.the.Earth.where.the.Earthquake.starts.
• Epicenter.–.location.on.the.surface.of.Earth.directly.above.the.focus.
• FaultB.associated.with.earthquake.activity.where.movement.has.occurred.
! Release.of.builtBup.energy.! Most.earthquakes.are.produced.by.the.rapid.release.of.elastic.energy.stored.in.rock.that.has.been.subjected.to.great.forces.
! When.the.strength.of.the.rock.is.exceeded,.it.suddenly.breaks,.causing.vibration.of.an.earthquake.
! Foreshock.–.small.quake.that.comes.before.a.major.earthquake.
! Aftershock'–.small.quake.that.comes.after.a.major.earthquake.
! Seismology.–.study.of.earthquake.waves.
! Seismograph.–.instruments.that.record.earthquake.waves.
! Seismograms.–.the.record.made.by.a.seismograph.
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Surface''! Seismic'waves'that'travel'along'Earth’s'outer'layer'
! Move'up,'down,'and'side'to'side'
! Most'destructive'earthquake'waves'
! Last'to'arrive'at'the'seismograph'
• P'waves''• They.push.(compress).and.pull.(expand).rocks.in.the.direction.the.wave.
travels.• Also.known.as.compression.waves.• Can.travel.through.solid,.liquid,.and.gas.• Fastest.waves.
• S waves • Shakes particles at right angles to their direction of travel • Also known as transverse waves • Can only travel through solids • Slower than P waves but faster than surface waves
The.difference.in.velocities.of.a.P.wave.and.S.wave.provides.a.way.to.locate.the.epicenter.! Use.a.travelBtime.graph.! Need.at.least.three.seismograph.station.data.
! Two'different'types'of'measurements'to'describe'the'size'of'an'earthquake'
(intensity'and'magnitude)'! Intensity'
''''A'measure'of'the'amount'of'earthquake'shaking'at'a'given'location'based'on'the'amount'of'damage'
! Magnitude'
''''A'measure'of'the'size'of'seismic'waves'or'the'amount'of'energy'released'at'the'source'of'an'earthquake'
Richter'Scale'
! Measures'the'magnitude'of'
an'earthquake'
! Based'on'the'amplitude'of'
the'largest'seismic'wave'
! 10Pfold'system'(ex:''The'amount'of'shaking'for'a'5.0'earthquake'is'10'times'greater'than'the'shaking'produced'by'an'earthquake'of'4.0'on'the'Richter'Scale'.
.
Moment'Magnitude.! More'precise'means'of'measuring'earthquakes'
! Amount'of'displacement'that'occurs'
along'a'fault'zone'
! Calculated'using'several'factors'! Average'amount'of'movement'along'the'fault'
! Area'of'the'surface'break'! Strength'of'the'broken'rock'
! Most'widely'used'measurement'for'earthquakes'because'it'is'the'only'magnitude'scale'that'estimates'the'energy'released'by'earthquakes'
! Seismic.VibrationBDamage.to.building.depend.on.several.factors.! Intensity.and.duration.of.
vibration.! Nature.of.the.material.on.
which.the.structure.is.built.! Design.of.the.structure.
! Liquefaction.! Stable.soil.turns.into.a.liquid.
that.is.not.able.to.support.buildings.or.other.structure.
! Seismic&sea&waves&! Triggered&by&an&earthquake&occurring&where&a&slab&of&the&ocean&floor&is&displaced&ver?cally&along&a&fault&
! tsunami&videos&
! Landslides.! Sinking.of.the.ground.triggered.by.the.vibration..
! Greatest.damage.to.structures.
! Fires.! Caused.by.ruptured.gas.lines.
! Short.range..! Methods.for.short.range.predictions.of.earthquakes.have.not.been.successful.
! Long.range.! Based.on.the.idea.that.earthquakes.are.repetitive.
! Seismic.gap:..an.area.along.a.fault.where.there.has.not.been.any..earthquake.for.a.longBperiod.of.time.
! h@p://www.sciencecourseware.com/eec/Earthquake/&
! Main&Ac?vi?es:&Time&travel&Graph&! Recommended:&Tutorials&(top&right)&! Tasks&–&use&different&tools&to&gather&and&record&in&journal&at&bo@om&of&screen&
! Show&teacher&aMer&you&verify&your&answers&! Main&Ac?vi?es:&Epicenter&and&Magnitude&
! Magma.vs..Lava.
! Magma.–.molten.rock.with.Earth.! Lava.–.molten.rock.on.Earth’s.surface.
! A mountain formed of lava and or pyroclastic material
! Lava Flow ! Pahoehoe: lava
flow resembles the twisted braids in ropes
! Aa: lava flow that has a surface of rough, jagged blocks with dangerously sharp edges and spiny projections
! Gases ! 70% water vapor ! 15% carbon dioxide ! 5% nitrogen ! 5% sulfur
! Pyroclastic material ! Fragments ejected
during eruptions ! Varies in size from
very fine and volcanic ash to pieces that weigh several tons
! Pyroclastic Flow ! Consist of hot gases,
glowing ash, and larger rock fragments racing down the steep slope
! Lahar ! Mudflow that occurs
when volcanic debris becomes saturated with water and rapidly moves down steep volcanic slopes
• The basic connections between plate tectonics and volcanism is that plate motion provide the mechanisms by which mantle rock melt to generate magma
• Ring of Fire: area around the pacific ocean with extreme volcanic activity
• Occurs within a plate, not plate boundary
• Most intraplate volcanism occurs where a mass of hotter than normal mantle material called mantle plumes rise toward the surface
! Small volcanic region a few hundred kilometers across within a plate
! Ex: Hawaiian Island