PLATE TECTONICS

Continental Crust Cooling rate Crystal size Density Composition Thickness

Oceanic Crust Cooling rate Crystal size Density Composition Thickness

Lithosphere/Asthenosphere

Tectonic Plate is a rigid piece of lithosphere floating on a partially plastic substrate (asthenosphere).

Pangea

Evidence for Plate Tectonics Continents ‘fit’ together

Evidence for Plate Tectonics Continents ‘fit’ together Fossil evidence

Evidence for Plate Tectonics Continents fit together Fossil distribution Glacier evidence: deposits, striations

Evidence for Plate Tectonics Continents fit together Fossil distribution Glacier evidence: deposits, striations Climate distribution

Location of Trenches, Ridges, Mountains

Evidence for Plate Tectonics Continents fit together Fossil distribution Glacier evidence: deposits, striations Climate distribution Location of mountain ridges, rifts, mid-ocean ridges, trenches

Testing the Sea-Floor Spreading Hypothesis

Magnetization

Evidence for Plate Tectonics Continents fit together Fossil distribution Glacier evidence: deposits, striations Climate distribution Location of mountain ridges, rifts, mid-ocean ridges, trenches Magnetic pattern of rock

Same Age Rocks

Evidence for Plate Tectonics Continents fit together Fossil distribution Glacier evidence: deposits, striations Climate distribution Location of mountain ridges, rifts, mid-ocean ridges, trenches Magnetic pattern of rock Common rock formations: same age

Volcano og%20Resources/Images/Plate%20Tectonics/Plate%20Tectonics/VolcanoStructure.jpg

Earthquake

Ring of Fire

The Hawaiian - Emperor Volcanic Chain

LOCATION OF HOT SPOTS

Evidence for Plate Tectonics Continents fit together Fossil distribution Glacier evidence: deposits, striations Climate distribution Location of mountain ridges, rifts, mid-ocean ridges, trenches Common rock formations: same age Magnetic pattern of rock Location of earthquakes and volcanoes

How does it work?

Wegener’s Continental Drift

Wegener’s Theory Problems 1)Continents plowing through the crust would destroy the crust 2)Continents are not moving apart at the speed Wegener proposed

Didn’t have a good explanation of the mechanism involved

Holme’s Convection Currents

Convection currents Gravity causes the heated mantle to sink The mantle heats up near the core and then rises again Conduction is the transfer of heat between 2 materials in direct contact with each other library.thinkquest.org/C003124/images/convect.jpg Click animation

Movement of mantle by convection allows melting and force to move plates

CONVECTION

Hot Spots – Hawaiian Islands

Evidence for Convection

Sea-Floor Spreading Hypothesis by Hess & Deitz CLICK Animation:

SEA FLOOR SPREADING

SUBDUCTION

Types of Plate Boundaries

Plate Boundary Transform, Divergent & Convergent SIMULATIONS ON ALL BOUNDARY TYPES CLICK

CONVERGENT BOUNDARIES

Types of Plate Boundaries Convergent boundaries

Convergent Boundary Oceanic & Continental CLICK

Andes Mountains Convergent Oceanic & Continental blue.utb.edu/paullgj/images/Conv_Cont_Ocean.JPG CLICK

Convergent Boundary Oceanic & Oceanic

Japan or Aleutian Islands Convergent Oceanic & Oceanic ceeps.colostate-pueblo.edu/.../smM1P1Fig15.gif

Convergent Boundary Continental & Continental

Himalayas Convergent Continental & Continental CLICK Convergent Simulation

DIVERGENT PLATES

Types of Plate Boundaries Convergent Boundaries Divergent Boundaries

Divergent Boundary Oceanic Sea-floor spreading, Mid-Ocean Ridges CLICK

Mid Atlantic Ridge Divergent Oceanic DIVERGENT SIMULATIONS CLICK CLICK

Divergent Boundary Continental Rift Valley

Mid Atlantic Ridge Divergent Oceanic DIVERGENT SIMULATIONS CLICK CLICK

TRANSFORM BOUNDARIES

Types of Plate Boundaries Convergent boundaries

Transform Boundary TRANSFORM SIMUALTIONS CLICK CLICK

San Andreas Fault Transform Boundary

Types of Plate Boundaries Convergent Boundaries Divergent Boundaries Transform Boundaries

Location of Plate Boundaries

Seven Major Plates Pacific North American South American African Eurasian Antarctic Indo-Australian

External Energy For Earth Sun & Moon keeps air and sea in motion, shapes surface Sun warms atmosphere & crust unevenly creating winds Winds drive ocean currents and water cycle Erosion from winds, rains, rivers, glaciers, and waves shape surface Weathering from winds and rains Sun & Moon Gravitational Energy, produces tides Planetesimal collisions

Internal Energy for Earth Radioactive element decay Core heat from layers pressure Convection currents Volcanoes Hot Springs Earthquakes