Geology Reference
In-Depth Information
atically mapping the seafloor, they discovered something they could not explain. Hidden
from view, under miles of water in the depths of the world's oceans, linear chains of moun-
tains circled the world like the stitching on a baseball. If this wasn't odd enough, the spines
of these ranges were always a long valley with extremely high heat flow and active rift
volcanism. The ocean floor was spreading apart, generating new oceanic crust along mid-
ocean ridges.
Map of the Mid-Atlantic Ridge in the North Atlantic Ocean.
The second piece of the puzzle followed the development of magnetometers that could
detect subtle differences in the strength and the sign (positive or negative) of magnetic
fields. Detecting the magnetic signatures of submarines proved to be an excellent way to
track and sink them—if one could discern their signal from the background magnetic signa-
