INTERNAL FORCES THAT SHAPE THE EARTH

Chp. 2 Section 3

Learning goal:

• Explain plate tectonics and the effects they have on our planet

Continental Drift Theory• All continents had

once been joined together in a super- continent called Pangaea, but slowly drifted apart.

• Evidence: the same crocodile fossils were found in Brazil and South Africa

• Evidence: continents can fit together like puzzle pieces

Plate Tectonics• Tectonic

plates=enormous moving pieces of the earth’s lithosphere

• Continents split apart due to the movements of tectonic plates

4 Types of Plate

Movement

1. Diverging Plates spread

apart *The space between is filled with

magma, which forms underwater mountain ranges

http://earthquake.usgs.gov/learn/animations/animation.php?flash_title=Divergent+Boundary&flash_file=divergent&flash_width=500&flash_height=200

An effect of divergent plate movement is a…VOLCANO!

Ring of Fire: zone around the Pacific plate known for multiple volcanic eruptions/earthquakes

One plate moving under another* “sub”=under, like

submarine

2. Convergent :Subduction

http://earthguide.ucsd.edu/eoc/teachers/t_tectonics/p_subduction.html

* “con”=to come together

like “con”vention*When the plates collide,

they create large mountain ranges like

the Himalayas.

3. Convergent: Collision

Plates come together

World’s tallest: Mount Everest

4) Transformation Plates slide past one

another

• When plates slide past one another at a fault, like the San Andreas, it can cause an earthquake

• Fault= crack/joint in the earth

Earthquakes

• Caused when tectonic plates grind or slip

• Richter Scale: scale that rates earthquakes (1=10)

Tsunamis• BBC

NEWS | World | The tsunami disaster explained

A giant wave caused by an earthquake on the ocean floor.

Create a newspaper article!

• Pick an event: earthquake, volcano eruption, tsunami…Can be more than one! (i.e. earthquake & tsunami)

• Explain exactly what happened. Be specific! Tell where

this happened, tell what type of plate movement it was and explain how those plates move, explain the damage of the disaster.

• Draw a picture to explain how this happened (plate movement arrows) and a picture of the damage it caused.

External Forces Shaping the Earth

Chp. 2 Section 4

Learning Goal:

• Describe mechanical and chemical weathering.

• Explain how water, wind, and glaciers affect the development of landforms

• Identify the basic components of soil

WeatheringProcesses that change the

characteristics of rocks.

Mechanical Weathering

• Processes that break rock into smaller pieces.

• Does not change composition of rock—just its size

Chemical Weathering• When composition of

rock is changed due to elements in the water and air which decompose the rock

• Ex: when iron rusts

Erosion= wearing away of rock, land or soil by wind, water, ice or gravity

Water Erosion• One form of water

erosion occurs when water flows in a stream or river

• When a river enters the ocean, the sediment it picked up during flow is deposited in a fan-like landform called a delta

Wind Erosion• The wind picks up and

transports sediment in different locations

• Deposits of loess, or wind blown silt or clay, are found across the world.

Glacial Erosion• Glaciation is

the changing of landforms by slowly moving glaciers

Article Title

Author Date

• Pick an event: earthquake, volcano eruption, tsunami…Can be more than one! (i.e. earthquake & tsunami)

• Explain exactly what happened. Be specific! Tell where this happened, tell what type of plate movement it was and explain how those plates moved, explain the damage of the disaster.

• At least 10 sentences, be creative but still cover the content!

Draw a picture to explain how this happened (illustrate the plate movements)

Draw a picture of the damage it caused

Keep it appropriate…

Caption explaining the above picture