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Density
Plate tectonics
Geological History
Earth's Layers
Mass extinction
100
What do crustal plates float?
They are less dense.
100
The earth's crust is divided into two types.
Continental and oceanic.
100
The layer that is typically oldest in a sample of layered rock
What is the bottom layer?
100
The outermost layer of Earth
What is the crust?
100
What is a mass extinction?
When more than 50% of organisms die out due to a change in climate.
200
Which is more dense but thinner crust?
oceanic
200
Transform boundaries move.
Past one another creating earthquakes
200
How are geologic periods divided?
Based on what lived at the time. Mass extinctions give rise to new organisms.
200
What scientists think is responsible for the movement of plates
What are convection currents?
200
Mass extinctions are caused by climate change. Climate change can be caused by many things. Name three causes of mass extinctions.
Volcanoes, basalt eruptions, greenhouse gasses, human activites, meteorite impact, continental drift.
300
which layer is more dense the asthenosphere or the mesosphere?
Mesoshpere
300
Alfred Wegener cited three pieces of evidence for seafloor spreading. Name all three.
Rock types and ages continents appear to fit together Same fossils on distant continents
300
The Rockies were formed through this process.
What is shallow subduction?
300
Detected by a compass and caused by the metal in the core
What is Earth's magnetic field?
300
If the age of the earth was equivalent to one year. How long ago did the dinosaurs go extinct?
About a week.
400
How can you change somethings density?
By increasing or decreasing it's volume. Adding heat energy will make the molecules move faster and spread out. The same amount of matter spread out over a larger volume lowers the density.
400
A continental crust and a oceanic crust collide, what happens?
The oceanic crust subducts because it is more dense. Mountains, volcanoes and earthquakes occur at this subduction zone ring of fire.
400
Fossils of fish found in layers at the tops of mountains are evidence that the mountain was once...
What is evidence that the mountain was once under water?
400
The majority of earthquakes and volcanoes occur here.
What is the edges of the tectonic plates?
400
Mass extinctions are followed by a change in the type of animals and plants that inhabit the Earth. What allows these new organisms like mammals to succeed?
Lack of competition.
500
Two continental plates coverge and cause a giant mountain range to form. Why is this different than what we see at subduction zones?
Subduction zones happen when plates of different densities collide. Because continenntal crust has the same density as continental crust, the collision causes big mountains rather than subducting and melting one of the plates.
500
Alfred Wegener did not understand what caused the plates to move around, this caused other scientists and the public to question his theory. Wegener suggested several mechanisms that proved to be incorrect. Name some evidence that later scientists used to confirm plate tectonic theory.
Relative and absolute dating of ocean floor. Paleomagnetic data confirmed that O. crust formed slowly outwards from divergent boundaries called mid-ocean ridges.
500
The cretaceous period ended with the
What is the extinction of dinosaurs that could not fly.
500
The layer of molten metals that is responsible for the Earth's magnetic field
What is the outer core?
500
Name three of the five big mass extinction events.
Cretaceous–Paleogene extinction event Triassic–Jurassic extinction event Permian–Triassic extinction event Late Devonian extinction Ordovician–Silurian extinction events