At mid-ocean ridges magma is forced toward the surface and pushes the two sides of the ridge apart. The rising magma fills the gap and solidifies adding a small amount of new ocean floor.
What is sea floor spreading
100
A rock that fits into the groups of light and glassy. It appears black but its mineral composition causes it to be classified as light.
What is obsidian
100
The type of magma which is the runniest and has the lowest viscosity
What is basalt magma
100
The point on the surface above the focus of an earthquake
What is the epicenter
200
The thinner yet denser part of the crust
What is oceanic crust
200
A boundary where two plates move apart from each other resulting in ridges.
What is divergent
200
Hot molten rock below the surface
What is magma
200
The type of volcano that forms over hot spots and has the most basaltic magma
What is shield volcanoes
200
This squeezes rocks together and causes them to bend or break and then the rocks above the fault move up and over the rocks below.
What is compression
300
The supercontinent explained in Wegner's hypothesis
What is Pangaea
300
A boundary where two plates collide often results in subduction and the creation of mountains. Can take place ocean-ocean, continent-ocean, and continent-continent.
What is convergent
300
A rock classified as dark and fine.
What is basalt
300
The type of rock that will solidify slowest
What is granitic
300
This scale measures the magnitude or energy released in an earthquake
What is the Richter scale
400
The hottest layer of Earth
What is the inner core
400
A boundary where two plates move horizontally along each other often causing faults.
What is transform
400
A texture in which both fine and coarse crystals are found
What is prophyritic
400
The type of volcano that is the smallest and forms volcanic island arcs
What is cinder cone volcanoes
400
This force occurs when rocks move sideways past one another
What is shear
500
The four pieces of evidence Wegner used to support his hypothesis
What are fossils, fit of continents, rocks, and climate
500
A tool that measures magnetic fields
What is a magnometer
500
Rocks are classified as this when they form beneath the surface
What is intrusive
500
The type of magma that is the thickest and has the most violent eruptions
What is rhyolite magma
500
Waves that have an up and down motion and arrive second at the seismic station