Download Chapter 2, Section 1 The Earth Inside and Out

Chapter 2, Section 1
The Earth Inside and Out
• The earth is the 3rd planet in our solar system,
which is part of the Milky Way galaxy.
•The earth is 93 million miles away from the
sun.
•The earth is about 24,900 miles in
circumference, and about 7,000 miles in
diameter.
Inside the Earth
• The core is the center of the earth – made of iron
and nickel.
– Inner core is solid (760 mile radius).
– Outer core is liquid (1,380 miles thick).
• The mantle surrounds the core (1,800 miles thick)
and makes up most of the earth’s mass.
– Magma forms in the mantle and can break through
the earth’s crust.
• The crust is the thin layer of rock at the earth’s
surface (19-37 miles thick).
On and Above the Earth
• Atmosphere – The layer of gases surrounding
the earth; contains the oxygen we breathe,
protects the earth from radiation and space
debris, and provides the medium for weather
and climate.
• Lithosphere – The solid rock portion of the
earth’s surface, the crust and the uppermost
mantle. The continents and seafloor are found
here.
On and Above the Earth
• Hydrosphere – All the water on the earth –
oceans, seas, rivers, lakes, and water in the
atmosphere.
• Biosphere – The part of the earth where
plants and animals live.
Continental Drift
• Continental Drift hypothesis was originated by
Alfred Wegener of Germany in 1912.
• Maintained that the earth was once a
supercontinent – Pangea or Pangaea – that
split and drifted away millions of years ago.
• Surrounded by an ocean called Panthalassa.