Chapter 1-3

Forces Shaping the Earth

Pg 34

Inside the Earth

-Three layers Layers of the earth

-

  • Core
  • Center of the earth
  • Inner core
  • Solid hot iron and other metals
  • Outer core
  • Liquid hot iron and other metals
  • Mantel
  • Surrounds the outer core
  • 1,800 miles thick
  • consists of 2 parts
  • part nearest the core is solid
  • rock on the outer mantel sometimes melts
  • comes out of active volcanoes
  • known as magma when it is still within the crust
  • known as lava when it comes outside the crust
  • Crust
  • Uppermost layer
  • Thin
  • Only 31-62 miles thick
  • Thinnest on the ocean floor
  • Thickest on the 7 continents - Continents
  • Massive land areas
  • North America
  • South America
  • Europe
  • Australia
  • Asia
  • Africa
  • Antarctica

Forces Beneath the Earth’s Crust

-earthquakes and volcanoes

Plate Tectonics-Movement

-Theory

  • States that the crust in not an unbroken shell but consists of plates
  • Huge slabs of rock that move
  • Floating on liquid rock just below the crust
  • Move in different directions

-

  • Pg 36
  • Plate Tectonics
  • Notice how the pieces of the puzzle fit together.
  • CD 3-D atlas
  • S. America fits into Africa
  • Pangaea
  • Page 45
  • Pangea
  • Super continent
  • A single landmass that existed millions of years ago.
  • Broke apart through tectonic activity
  • Still moving today
  • Aka “continental drift”
  • Alfred Wegener
  • 4 inches per year
  • same rate as my beard grows
  • western edge of SA moves about 1.8 inches per year
  • similar to the rate at which your fingernails grow

When Plates Meet

-Sometimes the plates spread away from each other

-Sometimes the plates move toward each other

  • If the 2 plates are “continental plates” the collision produces high mountain ranges – Himilayas
  • If one plate is continental and one is oceanic the collision thicker continental plate slides over the thinner oceanic plate
  • Forms volcanic mountains
  • Sometimes the plates move by sliding next to each other.
  • This movement creates faults
  • Cracks in the earth’s surface
  • Sudden movements can cause earthquakes

-

  • A sudden movement in the earth’s crust
  • Can cause severe damage
  • Pg 37
  • San Andreas fault
  • California
  • San Fran 1906
  • Loma Preada 1989
  • New Madrid
  • New Madrid
  • Alaskan
  • Can cause a tsunami
  • A tidal wave
  • Causes severe coastal flooding
  • Indonesia December 2005
  • Tsunami

Forces Shaping Landforms

-Weathering and Erosion

Forces on the earth’s surfaces that create change in landforms

Weathering

-the process of breaking surface rock into boulders, gravel, sand, and soil

- Mechanical weathering

  • Frost wedging
  • Water seeps into cracks of rocks freezes and expands
  • Plant root growth

-Chemical weathering

  • Acid rain
  • Pollution mixes with precipitation and falls to the earth
  • The chemicals eat away at the surface of anything
  • Carbonic acid
  • Water mixes with carbon dioxide and forms a mild acid that causes rocks to break down chemically
  • Creates caves
  • Stalagmites
  • stalagmites
  • Stalagtites
  • Stalagtites

Erosion

-Process of wearing away or moving of weathered materials

-Water

  • Most powerful agent of erosion
  • Grand Canyon National Park, Photos

-Wind

  • Video: The Dust Bowl
  • Create “wind dunes” – Loess
  • Loess

-Glaciers

  • Glacier Classification
  • Continental
  • Antarctica
  • Greenland
  • Mountain
  • Thousands found around the world
  • Melting due to global warming
  • When a glacier melts it is known as a “receding glacier”
  • Leaves behind debris
  • Moraine
  • Glacier moraine
  • SD Glacial Lakes

Chapter 3 Assessment pg 38