Shared Flashcard Set

Details

Plate Tectonics
A set of flash cards over Plate Tectonics
20
Science
8th Grade
03/11/2009

Additional Science Flashcards

 


 

Cards

Term
What is The theory of continental Drift?
Definition
That continents have slowly moved to their current position.
Term
What was the Pangea?
Definition
It was a once existing super-continent.
Term
How did Scientists use clues about the fossils found on each continent to hypothesize about the once super-continent?
Definition
They concluded that the same fossil was found on the west cost of Africa and the East coast of South America.
Term
How did scientists use clues about the climate to conclude the same thing?
Definition
They noticed they found plant remains of the same type that could only exist in warmer climates in Canada so they knew that Canada had to be at a lower climate area at one point in time.
Term
How did Scientists also conclude that using rock clues?
Definition
They knew that if the land masses were once connected then they had to have the same rock types at points were they once connected so they matched up the rocks also.
Term
How do scientists measure how deep water is?
Definition
They use Sonar which shoots a beam of sound waves to the seafloor, the longer it takes to get the waves back the deeper the water.
Term
what is seafloor spreading?
Definition
When Hott, less dense material, below Earth's crust, rises toward the surface at the mid-ocean ridges
Term
What is the Theory of Plate Tectonics?
Definition
That earth's crust and part of the upper mantle are broken into sections.
Term
What are plates?
Definition
Moveing on a plastic-like layer of the mantle.
Term
What excactly is the lithosphere?
Definition
The rigid ayer is about 100 km thick and generally is less dense then the materials underneath.
Term
What is the layer underneath the Lithospere called?
Definition
The Asthenosphere.
Term
What is the Asthenosphere?
Definition
The rigid plates of the Lithosphere float and move around on the asthenosphere.
Term
What are plate boundaries?
Definition
When the plates interact, the result or their actions show at the Plate Boundaries.
Term
What happens when plates move apart?
Definition
They form a rift vally.
Term
What happens when plates move together?
Definition
They are known as convergent boundaries, when they collide the denser plate sinks under the less denser plate and forms a volcano when a continental and an oceanic plate collide, but when two continental plates collide the cause mountain ranges.
Term
What happens when two oceanic plates collide?
Definition
They form a subduction zone, or a chain of islands.
Term
What about when plates slide past each other?
Definition
These are called transform boundarys. When two plates slide past each other they cause earthquakes.
Term
What are Convection currents?
Definition
They are thought to be the cycle of heat heating, rising, cooling, and sinking.
Term
What kind of plate movement caused the himalaya's?
Definition
Convergent plates.
Term
What kind of plate ovement causes a rift valley?
Definition
Divergent
Supporting users have an ad free experience!