Water, Water Everywhere - Geography - page 116

the sea. Give this process a couple million years (which it did), and the result is an ocean
of water too salty for human consumption.
How about de-salting the waters? That certainly is possible. Desalination (distilling sea
water to remove the salt) is a fairly simple process, and goodness knows the oceans
contain more water than humans will ever need. But de- salting seawater in the copious
quantities that cities require is very, very expensive. Few can afford it, so desalination is
not a particularly viable option.
Coming inland: Lakes
A similar brand of confusion reigns with respect to inland bodies of water. A lake is a body of water
completely surrounded by land. But when you open an atlas and browse the lakes, you find some are
called seas. For example, the Caspian Sea and Aral Sea are in Asia. The Salton Sea is in California,
and the Dead Sea is between Israel and Jordan. Logic would suggest that a “sea” should be bigger
than a “lake.” In reality, every one of the Great Lakes is larger than the Dead Sea, and so are a bunch
of not-so-great lakes.
The explanation is that the previously-named seas (which are really lakes) are salty. Each occupies a
basin — a depression in the landscape. Fresh water flows in, but nothing flows out. So you end up
having an ocean in miniature. That is, the rivers bring minute quantities of dissolved salts to the lake/
sea, which is essentially a dead-end repository. When the sun evaporates the surface waters, the salt
gets left behind. Keep this up for many, many years, and what you have is a lake whose waters are
not only salty, but are even saltier than your average ocean water. That's the way it is with the Great
Salt Lake, which apparently has every right to be called a sea but is not. Again, somebody way back
when gave a name to a water body, and the label stuck regardless of the logic.
Shaping Our World: Oceans
Because they contain more than 97 percent of Earth's water, oceans deserve to be considered in some
depth. And when you get to the bottom of things you find that oceans are home to important re-
sources. That in turn leads to the question “Who owns the oceans?” If that isn't enough, there's the
business of sea level change, which literally shapes and re-shapes our world.