Show:
Crust
Pangaea
Sea Floor Spreading
Advances In Technology
Magnetic Reversals
100
Is a drawing of what you see when you cut through an object.
What is a cross section.
100
All of the continents combined into one about two hundred million years ago.
What is Pangaea.
100
Scientists hypothesized that _____ is forced upward at a ridge by convection currents.
What is magma.
100
Technology that uses a device that sends sound waves and then records the time it takes to bounce back.
What is sonar.
100
The earth's magnetic field has a _____ pole and a _____ pole.
What is north and south.
200
Is a raised part of the sea floor which can become large enough to be considered an underwater mountain.
What is ocean ridge.
200
Scientist who discovered Pangaea.
What is Alfred Wegener.
200
The process in which the sea floor slowly increases in size because of the formation of new crust.
What is sea floor spreading.
200
Energy waves that are created by earthquakes or explosions.
What is seismic waves.
200
To detect magnetic fields sientists use a sensing device called a...
What is magnetometer.
300
Is an opening in the oceanic crust, where molten materials from earth's mantle can escape.
What is rift.
300
The continents changed positions very slowly moving over the surface of the earth a few centimeters every year. This theory is called...
What is the theory of continental drift.
300
In the _____, geologists were finally able to collect and study rock samples from the sea floor.
What is 1960's.
300
A long cylindrical sample of rock called...
What is a core sample.
300
_______ rocks provide a clue to the magnetic reversals.
What is igneous.
400
A large flat area on the sea floor.
What is abyssal plain.
400
The continents fit together like...
What is puzzle pieces.
400
When the magma reaches the more ridged upper mantle the magma is moved...
What is aside and the plates of the lithosphere move along with it.
400
___ ____ are used on board a ship to create seismic waves.
What is air guns.
400
Tiny _________ grains line up with earth's magnetic field just like tiny compasses.
What is magnetite.
500
Is a shallow underwater ledge located between a continent and the deep ocean.
What is continental shelf.
500
Scientist who studys fossils and rocks.
What is meteorologist.
500
The plates of the lithosphere are...
What is forced apart.
500
The ______ the sound waves take to return to the ship the deeper the water is.
What is longer.
500
Changes in the earth's magnetic field are _________ in the rocks that form on both sides of an ocean ridge.
What is preserved.