A short history of nearly everything - Bill Bryson [134]
Of the 3 percent of Earth's water that is fresh, most exists as ice sheets. Only the tiniest amount—0.036 percent—is found in lakes, rivers, and reservoirs, and an even smaller part—just 0.001 percent—exists in clouds or as vapor. Nearly 90 percent of the planet's ice is in Antarctica, and most of the rest is in Greenland. Go to the South Pole and you will be standing on nearly two miles of ice, at the North Pole just fifteen feet of it. Antarctica alone has six million cubic miles of ice—enough to raise the oceans by a height of two hundred feet if it all melted. But if all the water in the atmosphere fell as rain, evenly everywhere, the oceans would deepen by only an inch.
Sea level, incidentally, is an almost entirely notional concept. Seas are not level at all. Tides, winds, the Coriolis force, and other effects alter water levels considerably from one ocean to another and within oceans as well. The Pacific is about a foot and a half higher along its western edge—a consequence of the centrifugal force created by the Earth's spin. Just as when you pull on a tub of water the water tends to flow toward the other end, as if reluctant to come with you, so the eastward spin of Earth piles water up against the ocean's western margins.
Considering the age-old importance of the seas to us, it is striking how long it took the world to take a scientific interest in them. Until well into the nineteenth century most of what was known about the oceans was based on what washed ashore or came up in fishing nets, and nearly all that was written was based more on anecdote and supposition than on physical evidence. In the 1830s, the British naturalist Edward Forbes surveyed ocean beds throughout the Atlantic and Mediterranean and declared that there was no life at all in the seas below 2,000 feet. It seemed a reasonable assumption. There was no light at that depth, so no plant life, and the pressures of water at such depths were known to be extreme. So it came as something of a surprise when, in 1860, one of the first transatlantic telegraph cables was hauled up for repairs from more than two miles down, and it was found to be thickly encrusted with corals, clams, and other living detritus.
The first really organized investigation of the seas didn't come until 1872, when a joint expedition between the British Museum, the Royal Society, and the British government set forth from Portsmouth on a former warship called HMS Challenger. For three and a half years they sailed the world, sampling waters, netting fish, and hauling a dredge through sediments. It was evidently dreary work. Out of a complement of 240 scientists and crew, one in four jumped ship and eight more died or went mad—“driven to distraction by the mind-numbing routine of years of dredging” in the words of the historian Samantha Weinberg. But they sailed across almost 70,000 nautical miles of sea, collected over 4,700 new species of marine organisms, gathered enough information to create a fifty-volume report (which took nineteen years to put together), and gave the world the name of a new scientific discipline: oceanography. They also discovered, by means of depth measurements, that there appeared to be submerged mountains in the mid-Atlantic, prompting some excited observers to speculate that they had found the lost continent of Atlantis.
Because the institutional world mostly ignored the seas, it fell to devoted—and very occasional—amateurs to tell us what was down there. Modern deep-water exploration begins with Charles William Beebe and Otis Barton in 1930. Although they were equal partners, the more colorful Beebe has always received far more written attention. Born in 1877 into a well-to-do family in New York City, Beebe studied zoology at Columbia University, then took a job as a birdkeeper at the New York Zoological Society. Tiring of that, he decided to adopt the