Coast to Coast?

By Peter Staler

CONTINENTS IN MOTION: THE NEW EARTH DEBATE by WALTER SULLIVAN

397 pages. Illustrated. McGraw-Hill. $17.95.

During World War I, while a young German officer lay in a hospital recuperating from his wounds, he passed the time looking at maps and pondering the remarkable way in which the opposing sides of the Atlantic seemed to fit together. Alfred Wegener was not the first to notice that the bulging coastline of Brazil is a reciprocal of the west coast of Africa. For centuries scientists and cartographers speculated that a single large continent, which came to be called Pangea, had broken up into huge fragments that floated like rafts on the earth's plastic core until they reached their present positions. Such theories, however, were consistently hooted down with the derision scientists so often reserve for new ideas. Wegener, who had already established a reputation as a polar explorer and meteorologist, was undaunted. After his recovery, he devoted his life to proving the theory of continental drift. In 1930 Wegener died in Greenland in a search for evidence. But other men were able to carry on where he left off. Today, with slight variations, the idea that the earth is a fragile and constantly changing planet is generally accepted by most geologists.

Books dealing with the formation of the earth usually move only slightly faster than the glaciers that helped landscape the surface of the planet (about 20 miles a millennium). Continents in Motion is a striking exception. Walter Sullivan, science editor of the New York Times, concentrates as much on people and events as upon geological epochs. The result is a book nearly as entertaining as a good detective story--and considerably more informative.

Sullivan builds his case for continental drift carefully, treating skeptics as fairly as he does supporters of this once controversial concept. He is clearly no believer in Immanuel Velikovsky, whose theory that cataclysmic planetary events reshaped the earth during biblical times was first scorned and then suppressed by the scientific establishment. Sullivan acknowledges modern geologists' debt to Velikovsky for forcing them to re-examine old assumptions about the earth's formation. He deals much more favorably with the late Maurice Ewing, who founded Columbia University's Lamont Geological Observatory and provided the theoretical basis for things like submarine geology and attempts to study the underwater mountain range that bisects the Atlantic. Nor does he slight the host of others who have mapped the ocean bottoms, peered into smoking volcanoes or attempted to drill through the earth's crust to the semimolten mantle that surrounds its liquid core. Along the way, Sullivan scatters suggestive pieces of evidence with a skill that would do credit to Agatha Christie. He points out that the ancestors of certain North American animals seem to have come to their new home from Asia, something they could not have done if an ocean barred their way. He reports that the sea floor is spreading constantly on both sides of undersea ridges, notes that the Himalayas are growing at the rate of a few inches a century, forced upward as the Indian subcontinent pushes itself against the Asian mainland.

Sullivan's narrative does not make for casual reading. Despite its easygoing approach, Continents in Motion is a serious book. It is a disturbing one as well, for it ends on as deep a note of mystery as it begins. The theories of continental drift explain how the continents and the oceans that separate them were formed. But those theories can only hint at probable changes to come. The earth does not exist in a steady state; the forces that gave the planet its present topography are still at work. How they will reshape the earth or rearrange the continents is uncertain. What is certain is that, given time, they will.

Peter Stoler

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