The Geosphere
Download
Report
Transcript 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