Grade 9 Geography - Tectonics Flashcards
Who started the idea of continental drift?
Alfred Wegener
Pangaea?
a supercontinent 300 million years ago
what does Pangaea mean?
“all land”
What happened to Pangaea 200 million years later?
Pangaea began to break-up, the debris drifting to different directions
Why was Alfred Wegner’s hypothosis not accepted?
Because he couldn’t explain the force that moved the continents
What Canadian helped explain continental drift?
J. Tuzo Wilson
What theory was proposed in 1968?
The plate tectonic theory
How many plates is the world made up of?
about 20 plates
How many large plates is the world made up of?
about 7 plates
how did the continents move and float?
They floated on hot sediment
What caused the continents to move?
convection current
What were Alfred Wegener’s 4 proofs of continental drift?
- South America and Africa seemed to fit like jig saw puzzles
- Fossils of the same species were found in different continents
- different mountains seemed to have similar structure within different continents
- Ice plates covered South Africa, India, Australia.. which means these continents must of been under the equator at some point in time
What are the 2 causes of Tectonics?
- The actions within the earth
2. how the earth formed (Palegaea)
What are the 5 effects of Tectonics?
- mountain being created
- continent and island being created
- the formation and changes of the atmosphere
- disasters associated with land formation
- species evolution, changes, and adaptation
What are the 5 layers of the earth in order from outer to inner?
- Crust
- Asthenophere
- Mantle
- Outer Core
- Inner Core
Crust?
It’s a 5 to 80km layer that increases the temperature by 1 every 70m
Mantle?
It’s a circulation of melted rocks and pressured crystals that are between 1,000 and 2,000 degrees
Outer Core?
It’s where the magnetic flow lies in a temperature of 3,000 - 4,000 degrees
Inner Core?
It’s a dense solid of elements created by collisions and it’s the hottest layer
What are the 3 types of Tectonic Boundaries?
- Divergent
- Convergent
- Transform
Divergent?
When the plates move apart
Convergent?
When the plates move together
Transform?
When the plates rub together horizontally/vertically
What could be the 5 effects of a fault?
- Volcanic Eruption
- Earthquake
- Disasters
- Tsunami? (only in certain areas)
- Growing Mountains/ change of landscape
What are Faults caused by?
Continental Drifts
What are continental drifts caused by?
The rising magma/heat in the mantle
In which boundary does lava flow?
Divergent
What is the most dangerous boundary?
Convergent
What are the 6 things divergent plates release?
- Pressure
- Gas
- Energy
- Lava
- Rocks
- Minerals
What does major Convergent’s usually cause?
“bombs” or major Earthquakes
What does transformations create?
hills
What’s the Major transformation fault caused in California?
The San Arduous Fault
Which area of the world contains the most tectonic build up?
The Pacific Ring of Fire
Where is the Hot Spot with in the Pacific Ring of Fire?
Hawaii
How tall must a hill be for it to be considered a mountain?
more than 2,000 metres
What are the 2 types of Faults?
- Normal Fault
2. Thrust Fault
How many Earthquakes appear in Canada per year?
About 4,000
Where is the transform plate in America?
to the west right at the border that separates Canada and the U.S
At what magnitude are we unable to feel an earthquake?
1 to 1.9
At what magnitude can we start to feel an earthquake?
2 and above
How many levels above is magnitude 2 to 3?
10
At what magnitude may we only feel a P-wave?
1 to 4.5
What’s the lowest magnitude to maybe cause injury?
3
P-Wave?
Also known as primary wave, it’s when the ground shakes back and forth rapidly
S-Wave?
Also known as secondary wave, it’s when the ground lifts up and down rapidly
Which type of wave is more dangerous?
S-wave
At what magnitude might an S-wave occur?
5 to 10
Epicentre?
The type of fault released
Seismic Wave?
An energy wave that causes shaking about 200km away from the epicentre
How long do we have to get to a safe position during a p-wave?
5 to 15sec
How long does an s-wave occur?
10 to 200 secs
Seismic Gap Theory?
The theory that a big earthquake will occur along a fault line in a gap between high freqency clusters of smaller earthquake
How many different types of volcano’s are there?
6
What are the 6 types of volcano’s?
- shield Volcano
- Dome
- Composit Cone
- Lava Plateau/sill
- Cinder Cone
- Caldera
Shield Volcano?
It’s a diverging volcano with a low hotspot and many lava layers
Dome Volcano?
It’s a tall diverging volcano that has lava that contains silica with a deep hotspot
Composit Cone Volcano?
It’s a converging volcano that contains multiple mini paths that help release the pressure
Lava Plateau/Sill Volcano?
It’s a hotspot that is trapped under flat crust
Cinder Cone Volcano?
It’s a converging volcano that contains a lot of ash
When does the Cinder Cone Volcano erupt?
every 200 to 1,000 years
Caldera Volcano?
It’s a diverging volcano that contains the biggest vent but also contain a huge rock cap over top of opening
When does the Caldera Volcano erupt?
Every 10,000 to 1 million years
How long ago did the :Yellow Stone Volcano Erupt?
640,000 years ago
What are the 4 gases that volcano’s release
- Acid Particles/acid rain
- Water vapour
- Carbon Dioxide
- Sulfur Dioxide
What are the 3 types of matter that volcano’s release?
- Ash
- Rock debris
- lava Flow
How many eruptions can a volcano have?
1 to 5
How many types of acids are in Volcano’s?
5