The Dynamic Earth
Chapter 3
The Geosphere
 Geosphere- the solid part of the earth
– Rock
– Soil
– Sediment
The Geosphere
 Studying the earth’s interior
– Deepest well (12 km)
– Seismic waves
The Geosphere
 The Composition of the Earth
– Crust
– Mantle
– Core
The Geosphere
 Structure of the Earth
– Lithosphere
– Athenoshere
– Mesosphere
– Outer Core
– Inner Core
The Geosphere
 Plate Tectonics- rigid layer of the lithosphere
is divided into pieces called plates that glide
over the underlying athenosphere.
– Most geologic activity occurs where these
plates meet called plate boundaries.
– Colliding plates build mountains.
Plate Tectonics
Interior of the Earth and Plate
Tectonics
The Geosphere
 Earthquakes
– Occur along faults (breaks in the earths plates
at plate boundaries)
– Measured using the Richter Scale- each whole
# increase equals about 31 times more power.
 2.0- Smallest that can be felt
 9.5- largest ever recorded
Earthquakes
The Geosphere
The Geosphere
 Volcanoes- mountain built from magma
– Local effects- lava and ash flows down the
mountain can destroy the local area
– Global effects- ash in the atmosphere can
cause global climate change
Volcanoes
The Geosphere
 Erosion- the removal and transport of
surface material
– Water erosion
– Wind erosion
Erosion
The Atmosphere
 Composition
– Nitrogen- 78%
– Oxygen- 21%
– Other- 1%
The Atmosphere
 Air pressure
– More dense near the earth
– Almost all of the earth’s atmosphere is located
within 30km of the earth’s surface
The Atmosphere
 Layers of the
atmosphere
The Atmosphere
 Troposphere
– Up to 18 km high
– Weather occurs here
– Densest layer of the atmosphere
– Temperature decreases with altitude
The Atmosphere
 Stratosphere
– From 18 – 50 km high
– Temperature increases as altitude increases
– Ozone layer- filters out UV radiation entering
the earth’s atmosphere.
The atmosphere
 Mesosphere
– From 50 – 80 km
– Coldest layers of the atmosphere (-93 C)
The Atmosphere
 Thermosphere
– From 80 – 550 km high
– Hottest layer of the atmosphere (2000 C)
– Absorbs x-rays and gamma rays that enter the
earth’s atmosphere.
– Ionosphere- layer of ions found in the lower
thermosphere.
The Atmosphere
 Energy in the atmosphere
– Radiation-transfer of energy across a space.
– Conduction- heat flow from a warmer object to a
cooler object
– Convection- transfer of heat by air currents
The Atmosphere
The Atmosphere
 The Greenhouse effect
– Process of gasses trapping heat energy
 Water vapor
 Carbon Dioxide
 Methane
 Nitrous oxide
The Hydrosphere
 The hydrosphere includes all water on or
near the earth
The Hydrosphere
The Hydrosphere
The Hydrosphere
 Oceans
 Oceans
The Hydrosphere
– Salinity- the concentrations of all the dissolved
salts in ocean water.
The Hydrosphere
 Oceans
– Temperature zones
The Hydrosphere
 Oceans– The global temperature regulator- The ocean
absorbs energy from the sun and stores this
energy. This ability to absorb and store energy
regulates the global atmospheric temperature.
 Oceans-
The Hydrosphere
– Currents- surface currents are wind driven and
are considered warm-water or cols-water
currents.
The Hydrosphere
 Freshwater
– Around 3% of the earths water is freshwater.
– Most of the freshwater is locked in icecaps and
glaciers.
 River systems
– A network of streams that drains an area of
land.
The Hydrosphere
 Groundwater
– When water reaches the land as precipitation it
either runs off into a stream or soaks into the
ground.
– Most water enters the ground
– Aquifer- a layer of rock that stores ground water.
 Recharge zone- surface of the land where water
enters the aquifer
The Hydrosphere
The Biosphere
 Biosphere- the narrow layer around the
earth where all life is found
– 11 km below the surface of the ocean to 9 km
up into the atmosphere.
The Biosphere
 Requirements for life– Liquid water
– Temperature- between 10 C and 40 C
– Components of life are continually recycled
– Gravity to hold the atmosphere
– Energy from the sun
The Biosphere
 Energy is constantly added to the earth,
causing it to be an open system.
 Matter is not added to the earth causing it to
be a closed system.
The Biosphere