Earth's Layers & Composition
Mechanics of Plate Tectonics
Historical Evidence & Scientists
Plate Boundaries & Geologic Features
Seafloor Spreading
100
What is the lithosphere made up of?
The crust and the rigid upper layer of the mantle
100
What is the main driving force behind plate movement?
Mantle convection currents
100
Who was the scientist that came up with the idea of Pangaea and the theory of Continental Drift?
Alfred Wegener
100
What forms at a continental-continental convergent boundary?
Mountains
100
Who developed the idea of seafloor spreading?
Harry Hess
200
What is the primary composition of the inner and outer core?
The inner and outer core are both made up of mostly iron and nickel
200
What happens at a subduction zone and why?
One plate sinks under another. The sinking plate is more dense than the plate that stays above.
200
Why was Wegener's theory rejected at first?
He couldn't explain the mechanism behind the continental movement he proposed
200
What type of plate boundary causes the strongest earthquakes?
Transform boundaries
200
What happens at mid-ocean ridges?
New crust forms
300
Why is the inner core solid despite extreme heat?
Immense pressure
300
What role does the lithosphere play in plate tectonics?
The lithosphere is the rigid outer shell of the Earth that the tectonic plates are made of. That's why tectonic plates are also known as lithospheric plates!
300
What was Marie Tharp's major contribution to Geology?
Created the first complete map of the ocean floor and discovered the Mid Atlantic Ridge, used as evidence to support the theory of Plate Tectonics
300
Give an example of a slow change and a rapid change of Earth's surface.
Rapid changes: volcanic eruptions, landslides, earthquakes
Slow changes: seafloor spreading, mountain building, continental drift
300
What is the plate boundary where seafloor spreading happens?
Divergent boundary
400
What is the approximate temperature of Earth's inner core?
5,000-6,000°C (11,000°F)
400
How do convection currents move inside the mantle?
Magma closest to the outer core (heat source) rises, cools, sinks then starts the process over again.
400
What evidence did Wegener use to support continental drift?
Fossil Evidence, Continental Fit, Glacial Evidence, Landforms & Rock Layers
400
What major geological features form at an oceanic-continental convergent boundary?
volcanoes (that create volcanic islands like Hawaii) and deep sea trenches
400
Explain the process of seafloor spreading.
Pushes older seafloor away from the mid-ocean ridge as magma rises from the mantle.
500
How does the lithosphere differ from the asthenosphere?
The lithosphere is rigid while the asthenosphere is semi-solid.
500
What happens to old oceanic crust as new crust forms?
It gets subducted into the mantle, melted and recycled
500
Evience of ancient palm trees were found in Alaska, and evidence of glacier scratches were found in Africa. This is an example of what types of evidence?
Fossil evidence and glacier evidence
500
Name a real life example of each type of plate boundary
Convergent boundary (Himalayas, Appalachians, Rockies, Hawaii, Mariana Trench) Divergent boundary (Mid-Atlantic Ridge) Transform boundary (San Andreas Fault)
500
How does seafloor spreading support the theory of plate tectonics?
Showing that plates move as new crust forms and spreads.