The Solid EarthThe Solid Earth

Layers and Structure Layers and Structure (Intro to Geology)(Intro to Geology)

More than meets the eye…More than meets the eye…

What is the Earth like?What is the Earth like?

Earth like an Apple…Earth like an Apple…

Travel from the Outside In…Travel from the Outside In…

The Crust- the SKINThe Crust- the SKIN

Crust-Crust- made of mostly O and Si (and made of mostly O and Si (and others such as Al, Fe, Ca, Na, K and Mg)others such as Al, Fe, Ca, Na, K and Mg)

Oceanic- under the ocean

Thinner than continental. Continental- part of the land, under your feet

Mantle- the FLESHMantle- the FLESH

Mantle-Mantle- 1,800 miles thick, Divided into two 1,800 miles thick, Divided into two (2) parts, made of rock (2) parts, made of rock

Upper MantleLower Mantle

L A

Upper MantleUpper Mantle

Divided into (2) two parts- think L.A.Divided into (2) two parts- think L.A.

Asthenosphere- plastic like, semi-solid, flows like silly putty, caramel

Lithosphere- rigid (hard, stiff)

Note: includes the crust (can break!!!)

Lower MantleLower Mantle

Semi SolidSemi SolidWhat does it mean?What does it mean?Compared to taffy, caramel or rubber!Compared to taffy, caramel or rubber!

Outer CoreOuter Core

Liquid metalLiquid metal Ocean of Spinning Ocean of Spinning

metal!metal! Made up of Fe and NiMade up of Fe and Ni VERY Hot!!!!!! Hotter VERY Hot!!!!!! Hotter

than the Inner Core! than the Inner Core! WHY?WHY?

Inner Core- the PITInner Core- the PIT

Solid metalSolid metal Spinning metal!Spinning metal! Mostly iron (Fe)Mostly iron (Fe) Also nickel (Ni)Also nickel (Ni) Very hot!!!!!! BUT- cooler Very hot!!!!!! BUT- cooler

than the Outer Core! than the Outer Core! WHY?WHY?

Together with the Outer Together with the Outer Core it generates the Core it generates the Earth’s magnetic field!Earth’s magnetic field!

What does it all look like?What does it all look like?

The Layers…The Layers…

Lower Mantle

Upper Mantle

Oceanic Crust under ocean

Continental Crust

Do you Know it?Do you Know it?

This does not include the core!!!

You got it?You got it?

What is the Moho?What is the Moho?

Mohorovicic DiscontinuityMohorovicic DiscontinuityWhat is it?What is it?

Apples or avocados??? Apples or avocados??? What do you like? What do you like?

One last look... One last look...

Do you know it?Do you know it?

Plate TectonicsPlate Tectonics

Continental Drift and PangaeaContinental Drift and Pangaea

Continental DriftContinental Drift Puzzles and Alfred Puzzles and Alfred

Wegener (1912)Wegener (1912) Observations and Observations and

evidence: continetal evidence: continetal margins, fossils, rock margins, fossils, rock age, glaciers and age, glaciers and mountain chains.mountain chains.

Moving landMoving land Hypothesis: the Hypothesis: the

continents have once continents have once been joined together in been joined together in one big land mass>one big land mass>

PangaeaPangaea

PangaeaPangaea

How did it move? When?How did it move? When?

New Conclusive EvidenceNew Conclusive Evidence

Seafloor spreading- discovered in the 1947Seafloor spreading- discovered in the 1947 Moving seafloor creates mid-ocean ridgesMoving seafloor creates mid-ocean ridges New rock from the mantle replaces broken crustNew rock from the mantle replaces broken crust

Under the sea…Under the sea…

Mid-Atlantic RidgeMid-Atlantic Ridge Mid-ocean RidgesMid-ocean Ridges

The Big Picture: Plate TectonicsThe Big Picture: Plate Tectonics

The theory of plate tectonics describes The theory of plate tectonics describes how and why the continents move.how and why the continents move.

PlatePlate= rigid slab/piece of rock= rigid slab/piece of rockTektonikosTektonikos= greek word meaning = greek word meaning

“construction” or “to build”“construction” or “to build”

Can you make Pangaea?Can you make Pangaea?

Plate Tectonics 2Plate Tectonics 2

Plate Boundaries and MovementPlate Boundaries and Movement

REMINDER: Plate TectonicsREMINDER: Plate Tectonics

The theory of plate tectonics describes The theory of plate tectonics describes how and why the continents move. Think how and why the continents move. Think Pangaea!!!!Pangaea!!!!

PlatePlate= rigid slab/piece of rock= rigid slab/piece of rockTektonikosTektonikos= greek word meaning = greek word meaning

“construction” or “to build”“construction” or “to build”

How does this look like?How does this look like? The Earth’s crust is broken into large pieces The Earth’s crust is broken into large pieces

called called lithosphericlithospheric platesplates. Imagine a cracked, . Imagine a cracked, hard-boiled egg. hard-boiled egg.

Plate BoundariesPlate Boundaries

The Edges of the plates, where they touch other The Edges of the plates, where they touch other plates, are called plates, are called plate boundariesplate boundaries

Plate Movement vs. BoundaryPlate Movement vs. Boundary

The way the plates move, determines the The way the plates move, determines the type of plate boundary… meaning…type of plate boundary… meaning…

Convergent Divergent TransformTowards Each other Away from each other Slip sideways

past each other

Plate MovementPlate Movement

These plates move in three different These plates move in three different waysways

A.A. Towards eachotherTowards eachother

B.B. Away from eachotherAway from eachother

C.C. Slip sideways past eachotherSlip sideways past eachother

What does it look like?What does it look like?

Once again…Once again…

Divergent BoundaryDivergent Boundary

Plates pulling away from one anotherPlates pulling away from one another What do we get? Ocean Ridges (under water) What do we get? Ocean Ridges (under water)

or Rift Valleys (on land)or Rift Valleys (on land)

Transform BoundaryTransform Boundary Plates slide and grind next to each other, side to sidePlates slide and grind next to each other, side to side What do we get? Faults, earthquakes! What do we get? Faults, earthquakes!

Convergent BoundaryConvergent Boundary Plates push against each Plates push against each

otherother How many kinds?How many kinds? O+O, C+O and C+CO+O, C+O and C+C What do we get?What do we get?

What happens? Why?What happens? Why?

The movement of these plates over The movement of these plates over millions of years have caused the millions of years have caused the continents to continents to driftdrift (move). (move). Think Pangea.Think Pangea.

The oceans and continents sit on top of The oceans and continents sit on top of these plates and therefore they move these plates and therefore they move when the plates move. Even today!when the plates move. Even today!

Why? Why? Convection currentsConvection currents within the within the Earth Layers. Earth Layers. Think pot of boiling water!Think pot of boiling water!

Seismic MovementSeismic Movement

EarthquakesEarthquakes

What are Earthquakes? Where?What are Earthquakes? Where?

Vibrations of the Earth’s crustVibrations of the Earth’s crustWhere?Where?They occur mostly when rocks under They occur mostly when rocks under

stress suddenly shift or move along a stress suddenly shift or move along a faultfaultWhat is a What is a locked faultlocked fault??

Elastic Rebound TheoryElastic Rebound Theory

Words to know…Words to know…

Seismic Waves-Seismic Waves- energy in the form of energy in the form of vibrations as the rocks movevibrations as the rocks move

AftershocksAftershocks- smaller tremors, as the - smaller tremors, as the rocks come back into their original positionrocks come back into their original position

FocusFocus- where rocks first slip- where rocks first slipEpicenterEpicenter- point on the earth’s surface - point on the earth’s surface

directly above the focusdirectly above the focusMagnitude-Magnitude- how strong how strong

What’s it look like?What’s it look like?

Where do they happen?Where do they happen?

The Pacific Ring of FireThe Pacific Ring of Fire

What?What? Where?Where? What?What? Fault ZonesFault Zones VolcanoesVolcanoes TrenchesTrenches

How do we measure… just kidding!How do we measure… just kidding!

How do we measure?How do we measure?

SeismographSeismograph Detects and records Detects and records

seismic waves in seismic waves in three different ways three different ways

What kind of waves?What kind of waves? What are they called?What are they called?

Seismic WavesSeismic Waves P waves-P waves- primary waves- primary waves-

fastest, travel through fastest, travel through solid and liquidsolid and liquid

S waves-S waves- secondary secondary waves, travel through waves, travel through solid onlysolid only

Surface Waves-Surface Waves- when P when P and S waves reach the and S waves reach the surface, they become surface, they become surface waves, slowestsurface waves, slowest

Think water ripple Think water ripple effect…effect…

More waves…More waves…

Waves…Waves…

What scales do we use to measure What scales do we use to measure earhquakes?earhquakes?

MagnitudeMagnitude ( (Richter Richter ScaleScale)- measures )- measures energy released, energy released, related to cause. 1 related to cause. 1 and upand up

IntensityIntensity ( (Mercalli Mercalli ScaleScale)- measures )- measures amount of demage it amount of demage it causes, related to causes, related to effect. I to XII and effect. I to XII and descriptiondescription

Locating Locating an an

Earthquake Earthquake

Three Three Stations Stations neededneeded

Why?Why? How?How?

Locating an Earthquake…Locating an Earthquake…

TsunamisTsunamis Tsunamis-Tsunamis- giant wave caused by an earthquake whose giant wave caused by an earthquake whose

epicenter is on or under the ocean floor.epicenter is on or under the ocean floor.

How tsunamis work!How tsunamis work!

What does it look like?What does it look like?

Indonesia, 2004Indonesia, 2004

Banda Ache, IndonesiaBanda Ache, Indonesia

Videos, predictions and Videos, predictions and aftershocks…aftershocks…

Let’s see actual footage…Let’s see actual footage… Predictions?Predictions? Aftershocks?Aftershocks?