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