Social Studies - Power of the Planet Flashcards
What makes tectonic plates move?
They move by the convection currents in the mantle. Heat from the core e\heats the mantle which then rises
Definition of plate boundairies:
Where 2 or more plates meet which is referred to a plate boundary
Which is a divergent boundary?
When they move away from each other horizontally and new crust is generated.
Which is a convergent boundary?
When they move towards each other and crust is consumed in the mantle.
Which is a transform boundary?
When they move beside each other vertically and crust is neither created or consumed.
What is the continental crust?
When it is located beneath land masses and between 35-70km deep
What is the oceanic crust?
located beneath deep ocean and between 5-8km deep
Who is Alfred Wagener?
He was a German scientist who said that all the Earth land masses had been joined all together over 300 million years.
What is Pangaea?
Pangaea was the first major continent when Alfred knew all the land masses had been joined together. Pangaea broke into Laurasia and Gonduwana. (entire earth)
What are transform boundaries?
When two tectonic plates are sliding past each other and when associated with landforms are fault lines. A great example is the San Andreas Fault.
What are collision boundairies?
When two continental plates collide and neither can sink so fold mountains get created
What are destructive boundairies?
When the plates are moving towards each other, subducts and results in the formation of a ocean trench.
What are landforms that associated with destructive boundairies?
Ocean trenches
Stratovolcanoes
Caldera volcanoes
Fold mountains
What is subduction?
When the heavier oceanic plate slides under the lighter continental plate.
What is the landform cycle?
Uplift
Weathering
Erosion
Transportation
Deposition
What is uplift?
The process by which the Earth’s surface slowly rises.
What are the 3 forms of uplift?
Volcanic
Faulting
Folding
What is volcanic uplift?
After a volcanic eruption when there are deformations with the ground due to plate collision
Where are the hotspots in NZ?
Auckland, Christchurch, Dunedin, and Timaru and were active from 15-2 million years ago.
What is the difference between magma and lava?
Magma is the molten rock underneath the earth whilst lava is created when the magma has reached to the surface of volcanoes
What different types of volcanoes are there?
Caldera
Shield cone
Dome volcano
Scoria cone
What is viscocity?
The thickness of a fluid and its ability to flow.
What are stratovolcanoes?
Stratovolcanoes are when heaps of magma and lava flow out being very explosive
What are caldera volcanoes?
Calderas are very big craters after the collision of rock surrounding the vent after explosions that have massive amounts of magma and ash.
What are faults?
Faults are formed by the movement of large crustal blocks when forces in the Earth’s crust pull it apart.
What are the types of faults?
Earthquake fault
Rift valley fault
Uplift fault
What is the Alpine Fault?
The largest fault in NZ and when the fault has slipped the Pacific Plate side has moved up, growing the height of the Southern Alps.
What is an earthquake?
A earthquake happens when a slip or sudden fault happens and the tectonic plates get stuck at their edges due to friction
What could happen without faults?
No earthquakes or mountain building
Definition of a seismograph:
measures waves or movement on the crust
Definition of seismologists:
studies earth movement
How are earthquakes measured?
With magnitude’s from 1-10
What is the average rate the Southern Alps is rising?
1km every 100 years (Southern Alps)
What are folded mountains?
When mountains are formed by the folding of rock layers when rock layers are squished together and pushed upward.
Definition of monocline:
only 1 fold
Definition of anticline:
top of hill
Definition of syncline:
bottom of valley
What is weathering?
Where rock is dissolved, worn away, or broken down into smaller pieces
What are the two types of weathering?
Chemical
Physical
What is exfoliation?
Rocks are warmed and expand and shrink after they have cooled down
What is freeze-thaw action
Water seeps into cracks of rock then freezes and expands
What is biological weathering
Bacteria produces acids that eat away the rock surface
Definition of erosion:
the wearing of rocks, and how wind, water, and gravity carry away particles of rocks and soil broken down by weathering.
What are the 4 types of erosion in the landform cycle?
wind/aeolian
rivers/fluvial
wave/coastal
ice/glacial
What is wind/aeolian erosion
When wind gradually blows tiny particles of rock away. Many rocks have different minerals so wind wears them away at different rates.
What is river/fluvial erosion
When rain splashed onto rocks takes away minerals and flows them into rivers.
What is wave/coastal erosion
When waves take away the strength of the bottom of cliffs and eventually demolish
What is ice/glacial erosion
When glaciers move because of the huge mass of ice making the ice move down a hill.
What are valleys?
A low area of land between hills and mountains typically with a river or stream
What is lateral moraine?
Rock debris on side of glacier
What is terminal moraine?
debris at end of glacier
What is medial moraine?
debris lines formed where 2 glaciers meet
True or false: much of NZ have been shaped by glaciers
True
What is deposition?
When moving water, ice, or wind loses energy the material or sediments carried are then deposited. Many landforms are the result of deposition.
Definition for renewed:
to begin or take up again
What is transportation?
when water sweeps along any loose soil, sand, or rocks in its way
What is continental drift?
Continental drift is the moving of different plates and the separation, as how the earth has been separated into different continents over the years.
