Transcript File - Ms Hicks` Classes

Intro to Physical
Geography
Geology
The study of rocks and
the physical history of
the earth.
Continental
Drift
• 1915 German Scientist Alfred Wegener
suggested the theory of Continental Drift
• Believed that 300 million years ago, all Earth’s
land masses collided to form land mass he
called Pangaea (“all land”)
• 200 million years ago, Pangaea broke into
pieces, slowly drifting to the positions of the
continents today
Pangaea
http://eatrio.net/wp-content/uploads/2013/01/10.-pangea_politik.jpg
Wegener’s Four Proofs
• https://www.youtube.com/watch?v=_5q8hzF
9VVE Video About the 4 Proofs Of Continental
Drift
Evidence
of Continental Drift
• South America & Africa seem to fit together
Evidence
of Continental Drift
• Fossils of the same
plants and animals on
different continents
• E.g. the Mesosaurus, a
reptile which lived in
fresh waters - it could
not have traveled across
the sea.
Evidence
of Continental Drift
• There are mountains
and rocks of similar age
and structure on both
sides of the Atlantic
Ocean
E.g. The Appalachians
(eastern US and Canada)
and the Caledonian
Mountains in Northern
British Isles and Europe
Evidence
of Continental Drift
• Ice sheets covered
parts of southern
Africa, India, Australia,
and South America
approx. 250 million
years ago but these
places are warm today!
• Coral reefs around
Antarctica
An Unbelievable Theory ?
• Wegener died in 1930 before there was
acceptance of his theory
• He could not explain HOW the continents
moved – suggested tidal forces but did not
make sense
• 1960s, Canadian J. Tuzo Wilson helped to bring
up theory again
• Newer technology able to help
explain…
What Will the Earth Look Like
• https://www.youtube.com/watch?v=uGcDed4
xVD4 Vide of what the Earth used to look like
– and what it will look like in the far future
Pangaea Ultima
• The world may look like this in another 250
million years
Plate Tectonics Theory
• Helps to explain most geologic processes
• States that Earth’s outer shell consists of plates
that move causing earthquakes, volcanoes,
mountains and the formation of new crust
Plate Tectonics
Earth’s outer shell
consists of about
20 plates
most have both continental
& oceanic crust
Plate Tectonics
• Plates are
floating on
layer of hot
rock - the
mantle
Tectonic Video
• https://www.youtube.com/watch?v=mB2pzh
WUaiU Video About Tectonic Plates
Plate Tectonics
• Don’t entirely understand what makes the
plates move
• Think that unequal distribution of heat within
the core of the earths
causes convection
currents in the mantle
that push the plates
around
Plate Tectonics
• When plates are pushed together you could
get:
–
–
–
–
A mountain range
A volcano
New crust
An earthquake
The 3 Kinds of Plates
Boundaries
1) Divergent Boundaries
• The plates are moving away from each
other
• Ex: Mid-Atlantic Ridge
• Explains the hot springs that run
through Iceland
2) Convergent Boundaries
• The plates are
pushing toward
each other
• Ex: the boundary
between the
Eurasian and the
Indian plates
under the
Himalayas
3) Transform Boundary
• The 2 plates slide past
each other
• Ex: the boundary
between the North
American plate and
the Pacific plate in
California
Plate Tectonics
• Earthquakes, volcanoes and mountain ranges
usually follow plate boundaries
• Earthquake map below
Plate Tectonics
• Volcanic activity surrounding the Pacific Plate
has been labeled the “Pacific Ring of Fire”
Volcanoes
• Volcanoes can occur when one plate is pushed
under another (oceanic plates are heavier and
will push up the lighter continental plates)
Volcanoes
• Canada’s west coast
has currently
dormant (sleeping)
but not extinct
(dead) volcanoes
Mountain Ranges
• Mountains are created when plates push against
each other and fold the crust
• Mountain ranges can also be volcanic in nature
Watching the Himalayas Form
• https://www.youtube.com/watch?v=HuSHOQ
6gv5Y How the Himalayas Were Formed
Canada’s Mountains
New
West Coast Mountains
The Rockies
Old
East Coast Mountains
The Appalachians
Earthquakes
• Earthquakes happen when 2 plates rub
against each other, causing friction
Earthquakes
• The San
Andreas fault
is a large crack
in the earth's
surface where
two gigantic
plates are
sliding past
one another
(California)
Tsunamis
• Tsunamis, like the one that hit Japan in
March 2011, are caused by underwater
earthquakes
Tsunami March, 2011
Tsunami December, 2004
Tsunamis
• City of Banda Aceh,
Indonesia before
and after the
tsunami in 2004
Tsunamis and Canada
Location: West coast of British Columbia
Date: March 27, 1964
Description:
• The strongest North American earthquake of
the century, measuring 8.5 on the Richter
scale, struck off Anchorage, Alaska.
• It sent a tsunami travelling at over 700 km an
hour hurtling toward the BC coast. The 4.3 m
wave destroyed houses and flooded
basements in Hot Springs Cove and Bamfield
on the coast of Vancouver Island.
• The wave travelled up Alberni Inlet and
flooded town of Port Alberni.
• Luckily, no one was killed, but damages caused
by the wave totaled over $8 million.