Sea­Floor Spreading pg. 23­29
September 25, 2013
sea floor
cools
sea floor
ridge
sonar
to determine distance to an object
sea­floor spreading
molten material that erupts and cools
Sea­Floor Spreading pg. 23­29
September 25, 2013
molten material
magnetic strips
drilling samples
The further away from the ridge the samples were taken, the older the rocks were.
The younger rocks were always in the center of the ridges.
deep­ocean trench
The process by which ocean floor sinks beneath a deep­ocean trench
and back into the mantle.
Sea­Floor Spreading pg. 23­29
September 25, 2013
convection currents
sea­floor spreading
size and shape
convection currents
The ocean is changed in size and shape.
True
True
The Atlantic Ocean has only a few short trenches. The spreading ocean floor has nowhere to go.