Volcanoes & Earthquakes - CFAS

Volcanoes & Earthquakes
Wegener’s Pangaea
 Wegener’s observations about how continents seem to fit
together was the beginning of the Theory of Plate
 Animation of the movement of tectonic plates.
Continental Shapes Activity
 Use scissors to cut out each continent(Africa, Antarctica,
Australia, Eurasia, North America, and South America).
 Move the continents like a jigsaw puzzle to see how the
pieces best fit together.
 Tape your version of Pangaea together on a white sheet
of paper and name your “super continent”.
 Which continents do you recognize?
 Remember: The tectonic plates are not “floating” on
molten rock but are all in contact with each other.
Where Plates Meet Activity
 Using soda crackers and molasses model the
movements of the Earth’s crust.
 Are the tectonic plates shaped like the soda
 Question: What determines the shapes of the
tectonic shapes?
 Answer: The shapes of tectonic plates are
determined by earthquakes and volcanoes.
 The edges of the soda crackers we used in out activity
got “messy” just as the edges of tectonic plates get
“messy” from earthquakes and volcanoes.
 Did you notice how some molasses oozed up through the
holes in the crackers? The same thing happens to the
Earth’s crust where there is a thin or weak spot.
 Question: Why isn’t it likely that we would have a
major earthquake in New Brunswick?
 Could we have an earthquake in NB? Why?
Plate Movement News
 Quake stretched New Zealand toward Australia
 The making of mountains.
 The making of Mt. Everest
 Bill Nye – Earthquake
Mountain Formation Activity
Types of Earthquake Waves
 Use pages 317 - 318 in the text book to draw, colour, and
label the three types of earthquake waves.
 Primary or P Waves are like the compression of a slinky.
They are the fastest of the waves and travel through solids,
liquids and gases. These waves act as a warning for other
more powerful waves.
 Secondary or S Waves like a side-to-side motion of a slinky.
These waves are slower then the P Waves and only travel
through solids.
Surface Waves
Surface Waves are like ripples in a pond. These
are the slowest of the waves but tend to cause
the most damage.
 Scientists have two names for the source of an earthquake.
The Focus is the point of origin below the surface where P
and S Waves come from. The Epicentre is found on the
surface, surface waves come from this point.
Ground Movements
 Earthquakes can be identified as three basic types:
 Type 1: Convergent (push together)
 Type 2: Divergent (pull apart)
 Type 3: Transform (slide past one another)
 The San Andreas Fault is a well-known fault found in
California. A fault is the area where rocks break and move.
 What is liquefaction?
 Tsunamis from underwater earthquakes
 Tsunamis 2