Download Earth Science Ch.2

Earth Science Ch.2
Lesson 1
Sphere - ball shaped, with all points on the surface at an
equal distance from the center
Earth’s shape - not a perfect sphere, flattened at the
poles
with a slight bulge around the equator
diameter - 13,000 km
Earth’s Systems
Atmosphere - layer of gases surrounding the Earth
Hydrosphere - water on Earth’s surface, underground,
and in the atmosphere
Geosphere - the solid body of Earth, thin layer of soil
over a rocky center
Biosphere - all living things on Earth
Gravity - the force that every object exerts on every other
object because of their masses
The force of gravity depends upon the objects’ masses
and the distance between them.
The solar system formed from a cloud of dust and gas
called a nebula, which gravity pulled together
Earth’s spherical shape came from the pull of gravity on the
newly forming planet
Density - the amount of mass in a material per unit
volume
Temperature and pressure increases with
depth.
Earthquake waves are used to study the
interior of the Earth.
Earth’s Layers
Crust - brittle, rocky outer layer, made of
silicon and oxygen
Mantle - the thick middle layer in the solid part
of the Earth,
Lithosphere - the crust and the uppermost
mantle (brittle, rigid layer)
Asthenosphere - plastic layer within the
mantle
Core - the dense metallic center of Earth
Outer core - liquid iron
Inner core - dense ball of solid iron
crystals
Earth’s Magnetic Field
The liquid outer core spins and creates a
magnetic field.
This magnetic field that extends beyond the
surface of the Earth is called the
magnetosphere.
Lesson 3 Earth’s Surface
Oceans - over 70% of the Earth’s surface
Features that appear on dry land also
appear under the oceans.
Measuring Water Depth
Today’s oceanographers use sonar instruments
to generate a sound signal that is bounced or
echoed off the sea floor and then recorded on
board the ship. The speed of sound in water is
1,500 meters per second, 4 times faster than
the speed of sound in air.
By carefully measuring the round trip time of
the sound waves, the distance can be
measured accurately.
Landforms - topographic features formed by
processes that shape Earth’s surface
mountains, plains, plateaus,
canyons, and other features
Elevation - the height above sea level
Relief - differences in elevation of an area
between the highest point and the
lowest point
Topography - the shape of a geographic area
Plains - landforms with low relief and low
elevation
● cover most of Earth’s surface
● broad flat areas
● formed from sediments deposited by water
or wind, rich soils, good for crops, grazing
Plateaus - areas with low relief and high
elevation
● higher than the surroundings
● steep, rugged sides
● on every continent
Mountains - landforms with high relief and
high
elevation
● tallest landforms
● can form from the build up of lava
● also form from up lift of rocks
Glaciers are responsible for the creation of
many landforms