Download The Geosphere

The Geosphere
3.1
p.58-66
Our Dynamic Earth!
The Earth as a System

The Earth is a system


rock, air, water, and living things that
interact with each other.
4 parts:
Geosphere (rock)
 Atmosphere (air)
 Hydrosphere (water)
 Biosphere (living things)

Geosphere

Geosphere- the solid part of Earth.


all rock, soils, and sediments
Scientists have only drilled 12km deep.
How do we learn about inside of the
Earth?

They study the Earth’s interior by seismic
waves.
Same waves that are caused by
earthquakes.
 Measure changes in speed/direction of
seismic waves.


From this, they found that Earth is layered, and
have hypothesized about what those layers
consist of.
Composition of Earth

3 Layers:

1. The crust- thin outer layer. (light
elements).


2. The mantle- the layer beneath the crust.
(elements have medium density)


1% of Earth’s mass
64% of Earth’s mass
3. The core- innermost layer (dense
elements)

Radius is 3,400 km
Layers of the Earth:
Plate Tectonics
Tectonic Plates- pieces of the
lithosphere that move back and forth.
 Plate Boundaries- boundaries between
tectonic plates.

This is where plates separate, collide with
one another, or slip past one another.
 These forces cause earthquakes and
volcanoes.

Plates Moving
Plate Tectonics and Mountain
Building
When tectonic plates constantly move,
rock breaks/buckles.
 Plates collide, crust becomes thicker,
and mountain ranges form.


Himalaya Mountains: tectonic plates of India
and Asia collided 50 million years ago.
Northern India’s Himalayan
Mountains
Earthquakes
Fault- break in the Earth’s crust where
blocks of Earth slide by each other.
 Earthquakes- vibrations of the Earth’s
crust that are caused by slippage along a
fault.
 Earthquakes happen all the time—we
don’t feel all of them.
 The majority of earthquakes happen at
or near tectonic plate boundaries.

Richter Scale
Used by scientists to measure amt. of
energy released by earthquakes.
 magnitude- the measured amount of
energy coming from a quake.
 Smallest 2.0 and largest ever recorded is
9.5


Each whole number is 31.7 times more
magnitude
Volcanoes

Volcano- mountain built from magma
(melted rock) that rises from the Earth’s
interior to the surface.

Located near tectonic
plate boundaries
where plates are
colliding/separating
Earthquake Hazard Areas
Scientists can’t predict when earthquakes will
occur.
 Earthquake-hazard level is determined by its
past and present seismic activity.
 Earthquakes can occur in areas that are not
labeled as high-risk.
 High risk areas have started to build
earthquake-resistant structures.


Flexible so they will sway with ground motion.
Local Volcanic Effects

Clouds of hot ash, dust, and gases flow
up to 200 km/hr.
Can mix with water and
produce a mudflow.
 Causes building collapse.
 Buries crops and vehicles.
 Causes breathing problems

Global Volcanic Effects
Can change Earth’s climate for several
years.
 Sulfur-gas goes into the atmosphere.
 1991: Mount Pinatubo in the Philippines

Ash/gas entered atmosphere
 Sunlight decreased by 2-4%
 Avg. global temp. dropped by 10ths of
degrees Celsius over several years

Erosion

Erosion- removal and transport of
surface material
Wears down rocks
 Makes them smoother

Water Erosion

Water Erosion- erosion by rivers and
oceans.
Waves erode coastlines
 Rivers create gorges


Wind Erosion- erosion by wind
Places where there are little/no plants to
block winds
 Beaches, deserts (loose sandy soil)

The End