Theory Of Plate Tectonics
What are the 2 types of Earth's crust?
Oceanic-More dense and Continental- Less dense
Where is the youngest rock material found in the seafloor?
Along a ridge
What is convection?
It is the heat transfer by the movement of fluids, liquids, and gasses
Seismic waves are a good piece of evidence that the Earth's core is what?
Solid
What landmass existed 300 million years ago?
Pangea
How many major plates are there?
7 major plates
What is the longest chain of underwater mountains called?
Mid Ocean Ridges
What is the heat transfer within materials that are touching?
Conduction
What zone can't S-Waves travel through?
Shadow Zone
What 3 pieces of evidence did Wegener use to support his hypothesis?
Fossils
Mountains
Climate
What do divergent boundaries do?
They move apart from each other
What did scientists use sonar for?
To map the mid-ocean ridges
Radiation
The Earth was formed 4.6 billion years ago by ? and ? joining together.
Dust and Gas
Who came up with the hypothesis that all the continents were all together?
Alfred Wegener
What do convergent boundaries do?
They collide or smash together
What are the 3 pieces of evidence for seafloor spreading?
Molten material
Magnetic Stripes
Drilling Samples
Can gravity cause convection currents?
YES
What percentage of sulfur is the outer core made out of?
10%
Why was Wegener's hypothesis rejected?
He did not provide an acceptable explanation for convection currents to geologists declined him
When plates move apart what do they create?
Rift Valleys
What did Harry Hess NOT claim?
It is a heat transfer caused by convection when differences of temperature and density within a fluid
What are the 3 pieces of evidence for Earth's Layers?
Seismic Waves
Shadow Zone
Magnetic Field
How long did it take for Pangea to break apart?
More than tens of millions of years