Page 31 - (DK) Ocean - The Definitive Visual Guide

EARTH’S OCEANS CONTAIN about

320 million cubic miles (1.34 billion cubic
kilometers) of seawater. Dissolved in

this are some 53 million billion tons

(48 million billion metric tons) of salts,
gases, and other substances. The base

substance, water itself, has many unusual

properties, such as its high surface tension

and heat capacity, which are of tremendous

significance to everything from the oceans’
ability to support life to their stabilizing

effect on the world’s climate, and their

ability to transmit waves. Also of
significance is the variability of ocean

water—the sea is not uniform but varies

spatially and sometimes seasonally in

attributes such as its temperature, pressure,

dissolved-oxygen content, and level and
quality of light illumination. These attributes

are important in numerous key respects.

OCEAN WATER

CRASHING WAVE
This “barrel” wave is crashing onto the north
shore of the island of Oahu, Hawaii. Inspiring
sights such as this are only possible because
of some of the unusual properties of water.