Geology Reference
In-Depth Information
Wegener had proposed that the large continental landmasses moved through the crust
of the ocean floor like an icebreaker through ice, simply pushing their way through the
floor of the ocean. Other scientists recognized this explanation to be very unlikely and
yet could not offer a satisfactory alternative, so the question remained: How, or by what
mechanism,
do the continents move around the earth?
After many decades of research, scientists currently accept the idea that
movement of heated materials in the mantle of the earth, or
mantle convection,
plays a large role in driving the continental plates around the surface of the earth.
I explain the details of mantle convection and plate movement in Chapter 10.
Coming Together: How Technology Sheds
Light on Plate Tectonics
Since the early part of the twentieth century, there have been major breakthroughs in
understanding the earth's continental plates.
Marine geology
(the study of geology and
geologic features in the oceans) and advances in military technology have led the way.
Sea-floor mapping, or “How WWII advanced tec-
tonic theory”
During World War II, the use of submarines in warfare meant that the military needed ex-
tensive, detailed maps of the seafloor. When the seafloor of the Atlantic Ocean was
mapped, it revealed an interesting feature. Within the chain of undersea mountains
known as the Mid-Atlantic Ridge existed a deep crack, or valley. This
rift,
scientists now
know, is the boundary along which new ocean crust is created.
Mapping the seafloor during World War II led to other studies, including those investigat-
ing the age of the rocks beneath the ocean. The results of dating seafloor rocks finally
provided the key insight scientists were looking for to explain how the continents
moved around the surface of the earth. Had it not been for submarine warfare, funding
for undersea mapping may not have been available, and who knows when scientists
would have uncovered the key bit of information they needed to draw together, or unify,
the fields of earth science.
