Chapter 2 a living Planet The Solar System

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Chapter 2 A Living Planet

The Solar System

  • Consists of the sun and nine planets and other celestial bodies

    • Comets: spheres of ice and dust
    • Asteroids: large chunks of rocky material

The Structure of the Earth

  • Earth has 3 layers

    • Core: iron and nickel
    • Mantle: magma
    • Crust: thin layer of rock

The Structure of the Earth

  • Atmosphere: layer of gases

  • Lithosphere: includes crust and upper mantle

    • Forms ocean floor
    • Forms 7 continents: Asia, Africa, North America, South America, Europe, Australia, Antartica
  • Hydrosphere: water elements of earth

  • Biosphere: where plants and animals live

The Structure of the Earth

  • Continental Drift Theory

    • Earth was once a supercontinent that divided and slowly drifted apart over millions of years

Bodies of Water

  • Oceans and Seas

    • Covers 71% of earth
    • Pacific Ocean, Atlantic Ocean, Indian Ocean, Artic Ocean
    • Circulates through 3 basic motions
      • Currents: like rivers in ocean
      • Waves: swells or ridges produced by wind
      • Tides: created by gravitational pull of moon or sun

Bodies of Water

  • Hydrologic Cycle

    • The continuous circulation of water between the atmosphere, the oceans, and the earth

Bodies of Water

  • Lakes

    • Hold more than 95% of earth’s fresh water supply
    • Salt water lakes
  • Rivers and streams

Bodies of Water

  • Ground Water

    • Water held in pores of rock
    • Water table: level at which rock is saturated
      • Can change depending on amount of precipitation


  • Naturally formed features on the surface of the earth

    • Volcano -Plateau -Cataract
    • Strait -Mesa -Glacier
    • Island -Prairie -Cliff
    • Delta -Steppe -Mountain
    • Marsh -Valley -Butte
    • Oasis -Canyon -Swamp
    • Flood plain -River mouth -Cape
    • Bay -Harbor -Sea level


  • Oceanic landforms:

    • Continental shelf: earth’s surface from edge of a continent to deep part of the ocean
    • Ridges: places where new crust is being formed on edges of tectonic plates
    • Islands: formed by volcanic action, deposits of sand, or deposits of coral skeletons


  • Continental landforms

    • Relief: the difference in elevation of a landform from its lowest point to its highest point
      • Mountains, hills, plains, plateaus
    • Topography: the combination of the surface shape and composition of the landforms and their distribution in a region

Internal Forces Shaping the Earth

  • Plate tectonics

  • Earthquakes

  • Volcanoes

Plate Tectonics

  • Tectonic Plates: enormous moving pieces of the earth’s lithosphere

    • Move in 1 of 4 ways
      • Spreading or moving apart
      • Subduction or diving under another plate
      • Collision or crashing into one another
      • Sliding past each other in a shearing movement

Plate Tectonics

  • 3 types of boundaries mark plate movement

    • Divergent boundary: move apart horizontally
    • Convergent boundary: plates collide; one goes under the other or both plates crumble
    • Transform boundary: plates slide past one another
    • Fault: fracture in the earth’s crust


  • Crack in earth’s surface where magma, gases, and water from the lower part of the mantle pour out

  • Lava: magma that has reached earth’s surface


  • Ring of Fire

    • Zone around rim of the Pacific Ocean
    • Eight major plates meet here
    • Volcanic action and earthquakes often occur
    • Hot springs and geysers


  • Violent movement of the earth

  • Occurs when plates slide past each other at a fault

  • Seismograph: detects earthquakes


  • Location

    • Focus: where earthquake begins
    • Epicenter: directly above focus on the earth’s surface
  • Damage

    • Richter Scale: relative strength of earthquake
  • Tsunami

External Forces Shaping the Earth

  • Weathering

  • Erosion

  • Building soil


  • Physical and chemical processes that change the characteristics of rock on or near the earth’s surface

  • Creates sediment; smaller pieces of rock

    • Mud, sand, silt


  • Mechanical weathering: processes that break rock into smaller pieces

    • Does not change composition of rock
    • Frost, plant roots, human activity


  • Chemical weathering: rock is changed into a new substance as a result of interaction between elements in the air or water and minerals in the rock

    • Iron rusting, acid rain
    • Occurs more in warm, moist climates



  • Water erosion

    • Water flows in streams or rivers
      • Erode vertically and horizontally
      • Delta: fan-like landform that occurs when a river enters the ocean
    • Wave action along coastline
      • Can reduce or increase beaches


  • Wind erosion

    • Transports and deposits material in other locations
    • New landforms may be produced
      • Sand dunes
    • Loess
      • Wind blown silt and clay sediment that produce very fertile soil


  • Glacial erosion

    • Glacier: large, long-lasting mass of ice that moves because of gravity
    • Glaciation: the changing of landforms by slowly moving glaciers
    • Moraine: when rocks left behind by a glacier form a ridge or hill

Building Soil

  • Soil: loose mixture of weathered rock, organic matter (humus), air and water

  • Soil factors

    • Parent material
    • Relief
    • Organisms
    • Climate
    • Time

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