Transcript Geologic History with Inquiry Ques

Unit 2
Canada’s Physical Systems
Unit Learning Goal: I understand and can explain
the physical systems that created Canada and its
landforms.
Who Cares About Geology?
They Do!
Tsunami of 2004
https://www.youtube.com/watch?v=ZYeee5To48 (2 minutes)
Japan Earthquake: 11 March 2011
9.0 Magnitude Earthquake
https://www.youtube.com/watch
?v=w3AdFjklR50 (2 minutes)
8.2 Magnitude Earthquake in Chile
The 8.2 earthquake that shook northern Chile and surrounding
countries late Tuesday night was one of a string of recent
earthquakes along what is known as the “Ring of Fire,” a circle of
quake-prone areas on the Pacific Rim.
A magnitude 5.1 quake hit Los Angeles [a few weeks ago], followed
by aftershocks along the California coast. And South America will be
on the lookout in coming days for aftershocks that have already
started following Tuesday night’s temblor.
Both cities lie along the so-called Ring of Fire, where two plates
underneath the earth’s surface occasionally bump up against other
plates, according to Kate Hutton, staff seismologist at California
Institute of Technology.
“That affects South America, the California coast, Alaska, Japan, the
Philippines. Basically any places around the Pacific Rim are at risk,”
she said.
Pacific Ring of Fire
Discussion
Why would people live in an area that is prone to
natural disasters?
What criteria should be used to determine
whether rebuilding or relocating is the more
sustainable choice after a community has been
severely damaged by a natural disaster?
The Richter Scale
Magnitude
3.0–3.9
5.0–5.9
Description
Effects
Frequency
Minor
Often felt by people, but very rarely causes
damage. Shaking of indoor objects can be
noticeable.
Over 100,000
per year
Can cause damage of varying severity to poorly
constructed buildings. At most, none to slight
damage to all other buildings. Felt by everyone.
Casualties range from none to a few.
1,000 to 1,500
per year
Moderate
7.0–7.9
Major
9.0 and
greater
Great
Causes damage to most buildings, some to
partially or completely collapse or receive severe
damage. Well-designed structures are likely to
receive damage. Felt across great distances with
major damage mostly limited to 250 km from
epicenter. Death toll ranges from none to
250,000.
10 to 20 per
year
Near or at total destruction - severe damage or
collapse to all buildings. Heavy damage and
shaking extends to distant locations. Permanent
changes in ground topography. Death toll usually
over 50,000.
One per 10 to
50 years
What can be done to reduce the risk of earthquake damage
in tectonically active regions like British Columbia, or
flood damage in flood-prone areas along the Red River?
How do governments and agencies use spatial
technologies to monitor natural hazards and predict their
occurrence (e.g., violent weather, floods, avalanches,
earthquakes, icebergs)?
How might a community respond to long-term changes in
its environment, such as rising sea levels, coastal erosion,
or lower lake levels, that threaten its economy or survival?
How does your personal emergency preparedness plan
address natural risks, and what does it look like?
Earth’s Structure:
Label your handout
1216 km thick
of solid iron
2270 km of molten,
metallic magma
2885 km of
heavy rock
40 km of
solid light rock
Continental Drift
• In the early 1900’s Alfred Wegener, a
German geographer, noticed interesting
patterns on the Earth's surface:
1. Continents fit together like pieces of a
jigsaw puzzle
2. Mountain ranges separated by oceans
were made up of the same rock layers of
the same age in the exact same order
3. Fossils of dinosaurs were found on
continents now separated by oceans
4. Glacial scarring was found in places that
now have tropical (very hot) climates.
▫ Many scientists did not believe Wegener because he
could not explain how they moved
Plate Tectonics
• In the 1960’s a Canadian scientist named
J. Tuzo Wilson proved that Wegener had
been right.
▫ Earth is like a cracked hard boiled egg.
▫ The cracked plates move over liquid rock
(magma)
Convection Currents
Fold
Fault
Fold
Crust = Cold
Outer Mantle
Inner Mantle
Outer Core
Inner Core = Hot
Geology Terms
• Continents: are pieces of
land on the Earth’s surface
• Pangaea: means “all lands”
and was the name given to the
continents when they were
connected together
Let’s recap
Types of Plate Movement
• Converging Plates
▫ This is when two or more plates
move toward each other. The
result is usually fold mountains
and/or volcanoes such as those
found in the Andes Mountains
of S. America and the Rocky
Mountains of Canada.
Diverging Plates
• This is when two or more plates move away from each
other. The result is usually volcanoes and faults. If this
takes place under water we get an underwater ridge,
such as the Mid-Atlantic Ridge that runs along the
floor of the Atlantic Ocean. Where it is folded up above
the ocean surface we see the island of Iceland!
Transform Plates
• The is when two plates rub along side each other. They get
stuck, pressure builds up then is released as an earthquake,
such as those along the San Andreas Fault in California,
USA.
Shaping of the Earth
• Building Actions
▫ Folding: where plates force layers of rock upward to
create mountains. The Rocky Mountains and fold
mountains.
▫ Subduction: the process where one plate moves
under another plate which can cause volcanoes,
earthquakes, and deep ocean trenches
▫ Faulting: where two plates rub together, sometimes
forcing one over the other, creating new landforms
Wearing Down (Erosion) Actions