Plate Tectonics

Annotations:

• The deeper you go the higher  the temperature gets.

1. Exploring Inside Earth
   1. Evidence from rock samples

      Annotations:

      • Scientists drill holes into Earth to find out what is inside.
   2. Evidence from seismic waves

      Annotations:

      • Scientists send seismic waves into Earth.
2. Journey to the center
   1. Temperature

      Annotations:

      • The deeper you go, the higher the temperature.
   2. Pressure

      Annotations:

      • The deeper, the stronger the pressure.
3. The Mantle
   1. Asthenosphere

      Annotations:

      • The asthenosphere is the softest part of the mantle.
   2. Lithoshere

      Annotations:

      • The lithosphere is the upper part of the mantle and the lower part of the crust.
   3. Lower Mantle

      Annotations:

      • The lower mantle is solid and extends down to the core.
4. The Crust

   Annotations:

   • The crust is a solid layer of rock the is 4 to 5 kilometers thick.
5. The Core
   1. The Outer and Inner Core

      Annotations:

      • The outer core is liquid, but the inner core is solid.
   2. The Core and Earth's magnetic Field

      Annotations:

      • Our planet is like a giant magnet bar, and the core is the magnet.

1. Convection currents in Earth
   1. Caused By Mantle

      Annotations:

      • Currents are caused by the heat from the core and mantle.
2. Convection currents
   1. A current that transfers heat

      Annotations:

      • A convection current is continuos as long as there is heat.
3. Types of Heat Transfer
   1. Radiation

      Annotations:

      • Radiation is transfer of energy through space(air).
   2. Convection

      Annotations:

      • Convection is heat transfer through fluids.
   3. Conduction

      Annotations:

      • Conduction is heat transfer through contact.

1. Continental Drift
   1. Evidence From Land Features

      Annotations:

      • The continents all fit together, just like a jigsaw puzzle.
   2. Evidence From Fossils

      Annotations:

      • The fossils of the same organisms were found in far apart continents, today.
   3. Evidence From Ancient Climate Zones

      Annotations:

      • Fossils of tropical plants found in Antartica and sediments from glaciers found in Africa conclude that climate was different back then, meaning that the continents either moved away from the equator or to the equator.
2. Wegner's Hypothesis Rejected
   1. Wegner's hypothesis is rejected.

      Annotations:

      • Most geologists rejected Wegner's hypothesis because he couldn't identify the cause of continental drift.

1. Mid-Ocean Ridges

   Annotations:

   • Scientists use Sonar to map outh a mid-ocean ridge(an underwater mountain chain).
2. What is Sea-Floor Spreading

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   • The sea-floor spreads apart along mid-ocean ridges, carrying continents with them.
3. Evidence for sea-floor spreading
   1. Evidence from molten material

      Annotations:

      • Scientists discover molten material and use it for evidence.
   2. Evidence from drilling samples

      Annotations:

      • Drilling samples from the ocean floor give evidence of sea-floor spreading.
   3. Evidence from Magnetic Stripes

      Annotations:

      • Rock patterns give evidence of sea-floor spreading.
4. Subduction at Trenches
   1. The Process of Subduction

      Annotations:

      • A part of the process of subduction is when the ocean floor sinks into the mantle.
   2. Subduction and Earth's Oceans

      Annotations:

      • Sea-floor spreading and subduction are changing the size and shape of the oceans.

1. How Plates Move

   Annotations:

   • The theory of plate tectonics  explain the activities of Earth's plates.
2. Plate Boundaries
   1. Spreading Boundaries

      Annotations:

      • Spreading boundaries happen when two plates spread apart.
   2. Colliding Boundaries

      Annotations:

      • Colliding boundaries occur when two plates come together.
   3. Sliding Boundaries

      Annotations:

      • Sliding boundaries occur when two plate slide past each other, moving in opposite directions.