Tectonics
What is the slowest and thickest layer of the Earth?
Mantle
What types of features do transform boundaries create?
Abyssal plains, earthquakes
What are the 4 types of erosion?
1.ICE
2.GRAVITY
3.WIND
4.WATER
Where do tides occur and in what intervals?
All coastal areas, large lakes
Intervals of 12.5 hrs, creating 2 high tides and 2 low tides (semi-diurnal)
What is upwelling caused by?
Winds
Topography- mid-ocean ridges/ sea mounts
Oceanic- Thin/dense, basaltic rock- iron/magnesium
Continental- Thick/less dense, granite
What boundary is a constructive zone?
Divergent
What are the 3 types of weathering?
- Physical: Temperature
-Chemical: Water
-Organic: Lichen
Compare spring v. neap tides.
Spring- plants align, large tidal range
Neap- right angle, smallest tidal range
What activity does La Nina increase?
Increases hurricane activity in Atlantic basin.
What is the theory of continental drift?
Alfred Wegener & Pangea
Jigsaw-like fit, matching rock layers, identical fossils on coasts
How does the mantle move the crust?
Convection currents- Molten rock of mantle moves because of temperature-driven density changes.
Which shore has granite/igneous rock and is very resistant to weathering/erosion?
Rocky shore
Tidal range varies due to...
- Gravitational effects
- Coastal features
-Environmental factors: Wind, air pressure, and size of the body of water
ENSO- Explain normal conditions.
100 extra points
•Strong south-westerly winds blow water away from S. America, causing upwelling > high productivity > increase fish (sardines, anchovies) > supports consumers.
•On the other side of Pacific, these westerly winds push warm water towards Australia/Asia (0.5m) > water evaporates > massive storm clouds and rain in Australia/Asia.
What is seafloor spreading?
A mountain range with a central valley on an ocean floor at the boundary between two diverging tectonic plates, where new crust forms from upwelling magma.
How does a tsunami form? 4 steps.
100 extra points.
A. Underwater/seafloor earthquake
B. Stored energy released to water
C. Water is displaced and moves quickly
D. As water shallows, wave slows and grows exponentially in height.
Which shore is
-Sheltered/partially enclosed
-Brackish
-Protected from weathering/erosion
-High sedimentation and high turbidity
Estuary
Currents are created by different physical forces such as... (6 types)
wind, temperature, salinity, density, the Coriolis effect and the shape of the seabed
What is El Nino?
100 extra points
A warm current that develops off the coast of Ecuador around December, which can cause widespread death within local food chains.
E-W trade winds reduce, preventing warm water/moist air from moving west > warm water builds along S. America and Indonesia/Australia experience drought conditions.
What are paleomagnetic strips?
Seafloor spreading + reversals in magnetic field.
-Pattern originated around mid-ocean ridge where crust is weak, and magma pushes through.
-Particles of magnetite in basaltic rock within molten magma align with Earth’s magnetic field and gets locked in place as it cools.
How are hydrothermal vents formed? 6 steps.
100 extra points.
1. Fissures/cracks (divergent/convergent)
2. Cold sea water seeps inside cracks
3.The cold water is heated by magma
4.The hotter water dissolves more minerals (iron, copper, zinc sulfides) making the water black.
5.The hot water (100C+) increases in pressure, forces the water back out.
6.As the hot/mineral rich water is rapidly cooled by the surrounding cold water, causing minerals to build up a hydrothermal vent ‘chimney’.
What 2 factors affect morphology?
1.Relief- slope of the shore
2.Size of the sediment- depends on level of exposure to weathering/erosion/sedimentation.
Compare surface v. deep currents
Surface- wind, convection currents
Deep- density-driven via salinity and temp.
Explain the global conveyor belt.
100 extra points.
Arctic (ice forms, salt left behind)>downwelling>Antarctica>current divides> Indian ocean and Pacific Ocean (warms)> reconnects in Indian ocean> Arctic