If you were lost, how could a dog help?

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If you were lost, how could a dog help?
A new study says that dogs choose the direction
they relieve themselves based on our planet's
magnetic field.
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Inside the EarthHow do scientists know?
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Earth in General

• 3 Layers
• Crust
• Mantle
• Core
• Diameter
• 12,750 km

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Cross Section Diagram
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Overview of the Crust

• Solid Basalt and Granite
• 5-100 km thick
• Coolest in temperature
• Least dense
• 2.2-2.9 g/cm3
• Like the shell of egg, is brittle and can break
• Layer we live on

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What is the difference between sediment and
bedrock?
Sediment is Smaller pieces of broken rock mixed
with organic material and remains
Bedrock is rock underneath the accumulated
sediment
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Overview of Crust (continued)

• Major changes
• Plate Tectonics
• Minor changes
• Weathering erosion
• Deposition of sediments
• Two types of Crust
• Oceanic (very dense, made of basalt)
• Continental (less dense, made of granite)

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Example of minor change a bit of New Hampshire
folklore
For A. Cleary
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Oceanic and Continental Crust

• Oceanic Crust
• Mainly Basalt
• Thinnest part of crust 5 km thick
• Density 3.0 g/cm3
• Ocean puddles on top
• Youngest part of crust, new crust is made here

• Continental Crust
• Mainly Granite
• Thickness varies but 30 km thick
• 100 km thick under Himalayans Mts.
• Density 2.7 g/cm3
• Oldest part of crust

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Overview of the Mantle

• Like white of egg
• Hot layer of semi solid rock
• Contains more iron, magnesium and calcium than
  crust
• Hotter denser temp and pressure increase
  w/depth
• 2900 km thick
• Density 3.4 5.6 g/cm3
• Multiple layers which have
• different densities

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Upper Mantle and Lower Mantle

• Upper Mantle
• 720 km thick
• Density 3.4 4.4 g/cm3
• 1480 C, rock is near melting
• Magma from some volcanoes can originate here

• Lower Mantle
• 2170 km thick
• Density 4.4 5.6 g/cm3
• 2600 C
• Higher level of magnesium silicon oxides

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Overview of the Core

• Mostly iron nickel, metal
• Core is not rock or fire
• 3300 km thick
• Twice as dense as mantle

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Outer Core

• Liquid nickel and iron
• 2200 km thick
• Density 9.9 12.2 g/cm3
• 3800 C

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Inner Core

• Solid nickel and iron
• 1250 km thick
• Density 12.2 13.1 g/cm3
• 4300 C

The inner core is solid but hotter than the
outer core why?
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Where does the core get its heat?

• Chunks of material collided and stayed together,
  (Heat from these collisions can be on the order
  of 10,000 kelvins about 18,000 degrees
  Fahrenheit).
• Friction, when denser core material sinks
• Decay of radioactive elements, mostly uranium and
  thorium according to physicists.

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Earths Layers

• How are the earths layers similar to an egg?
• Shellcrust
• Egg whitemantle
• Yolkcore

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Interactions between Layers

• Lithosphere

• Includes crust and solid, uppermost part of the
  mantle
• Broken into about 19 pieces, these pieces are
  called PLATES
• The plates move on top of the Asthenosphere
  (which is a thin layer of the upper mantle)

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Interactions between Layers
Asthenosphere

• Beneath the lithosphere, in the mantle, lies a
  soft, relatively weak region of rock that flows
  slowly (like soft plastic or hot asphalt)
• Convection Currents that drive the movement of
  plates happen in the Asthenosphere

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Vocabulary expected to know

• Sphere shaped like a ball
• Hemisphere half of a sphere
• Interior inside
• Exterior outside
• Cross Section diagram that shows a piece cut
  out, so you can see the inside
• Molten melted, usually referring to material
  that melts at very HIGH temperature

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Vocabulary expected to know

• Lava melted rock touching atmosphere
• Magma melted rock below the crust
• Tectonic Plates broken pieces of the lithosphere

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Tectonic Plates

• Earths crust is broken into about 19 pieces
• These plates move on top of the asthenosphere
  (thin layer of the upper mantle)