2025/2026
What is the inner core - Answers - Deepest component, center of the Earth
- Solid
- 1300 km thick
- High temp
- Composed of iron (90% by weight) and other elements (Sulphur, Oxygen, nickel)
What is the Outer Core? - Answers - Liquid
- Composition similar to inner core
What is the Mantle? - Answers - Solid
-surrounds the core
- Composed of iron-rich and magnesium-rich silicate rock
-flows slowly
What is the crust? - Answers - Outer rock layer of Earth
- low density
- 2 kinds of the crust
What is more dense, crustal or mantle rocks? - Answers Mantle Rock
What is more dense, Continental crust or oceanic crust? - Answers Oceanic crust
What is continental drift? - Answers - proposed by Alfred Wegener, 1912
- The continents were fit, until being distributed
What is Oceanic spreading? - Answers - Oceanic ridges (e.g. Mid-Atlantic Ridge)
- Iceland: where the Mid-Atlantic Ridge rise above sea level
What is Continental Spreading? - Answers - Pulls apart at much slower rates compared to
oceanic spreading
- Typically does not form on plate boundaries
(e.g. African Rift)
, What is oceanic-continental? - Answers When one edge of a lithospheric plate is forced below
the edge of another
Are all the transforming boundaries in the ocean? - Answers Most are, but not all (e.g. San
Andreas Fault)
What are the rates of plate motion? - Answers 7 cm/year
What happened as a result of the seafloor spreading in 1963? - Answers - A new crust was
added to edge of plates at mid-ocean ridges
- Gave a mechanism for Wegener's theory
What are some examples of Hot Spots? - Answers The Hawaiian Islands, Yellowstone Park
What was Pangea? - Answers The largest continent existed 200 million years ago
What were the two sides of Pangea? - Answers Laurasia (North) and Gondwana (South)
What is the evidence for Pangea's existence? - Answers - Similar fossil plants and animals on
different continents
- Ancient glaciation on several continents (Ice flow only makes sense if Pangea existed)
What's some more evidence for Pangea/continental drift? - Answers - Geometry of continent
shorelines
- Matching ancient rocks and fossils
- Ancient ice-sheet glaciation
What two locations have the remains of the reptile: Mesosaurus, been found? - Answers Brazil
and Africa
What are the hazards of Boundaries that slide past each other (San Andreas Fault)? - Answers
Appreciable earthquake hazards
What are the hazards of Convergent plate boundaries where one plate sinks (Subduction zones)?
- Answers Explosive volcanoes and earthquake hazards
What are the hazards of Convergent plate boundaries where continents collide (Himalayas)? -
Answers High topography and earthquakes
What kind of natural disaster is the most common? - Answers Earthquakes
What is the average finacial lost due to a natural hazard? - Answers $50-$200 billion/yr
Where was is the most expensive disaster to date? How much did it cost? - Answers Japan in