By Ron Lora

Saturday's earthquake in Chile is linked directly to the earthquake that Charles Darwin witnessed 175 years ago at the same geological fault. He was the sole scientist on H.M.S. Beagle, whose mission it was to complete a survey of Patagonia and Tierra del Fuego, and map the shores of Chile, Peru, and certain islands in the Pacific.

It was the most important event of Charles Darwin's life. Leaving England at the end of 1831, he and 73 other shipmates began a five-year voyage around the globe to engage their mission. It was on that trip that the youthful naturalist made discoveries in the Galapagos Islands that forever altered our thinking about the riddle of existence.

In Chile, which sits on what was not yet known as the Pacific Ring of Fire, Darwin lived through the earthquake of 1835 that brought death and destruction, and which geologists today estimate was of 8.5 magnitude. Running for several hundred miles along the same section of the fault that fractured on Saturday, it made a terrific impression on him. He had seen that the earth could tear apart.

Indeed, he writes in "The Voyage" that it destroyed one of man's oldest illusions; namely, that the earth is solid. Instead, it "moves beneath our feet like a crust over fluid; one second of time conveys to the mind a strange idea of insecurity, which hours of reflection would never create."

Many of Darwin's passages would apply to last Saturday's quake: "I felt the earth tremble....The rocking was most sensible....There was no difficulty in standing upright; but the motion made me giddy." Concepcion had been reduced to rubble. Afterward, like today, the "frequent, almost incessant tremors, occasional shocks more or less severe, and distant subterranean noises, kept everyone in anxious suspense."

The most remarkable effect of the earthquake, wrote Darwin, was that around Concepcion the land had undergone permanent elevation by two or three feet. He also noted the damage caused by what we call a tsunami wave, triggered by the earthquake.

Other experiences in Chile contributed to his rapidly developing view of an unsettled earth. On at least two occasions he took a mule trip up the high mountains. There he saw the wearing processes of the earth in the mountain ranges of the Andes, and most interesting of all: seashells at 12,000 feet altitude! Did it not prove that one of the world's highest mountain ranges was once under water? That, assuredly, was not the prevailing view in the 1830s.

He found evidence of petrified seashells during another mule trip that he took into the Andes 50 miles north of Valparaiso. Always there was something new. Among the shells were thousands of fossilized trunks of trees (one of them eighteen feet in circumference), sprung from a volcanic soil that too had once been beneath the sea!

Darwin had taken with him "The Principles of Geology," by Charles Lyell, England's foremost geologist. In it he encountered the view that the earth was much older than commonly believed. Because time itself could now be thought of as reaching back through eons, it therefore was possible to think of mountains being thrust up gradually through millions of years; and more, although counterintuitive, it was even possible because of repeated upheavals and injections to understand why loftier ridges in the mountain ranges could be younger than less lofty ones.

"Who can avoid wondering at the force which has upheaved these mountains," he wrote, "and even more so at the countless ages which it must have required, to have broken through, removed, and leveled whole masses of them?"

From a thousand observations and impressions such as these, the young naturalist formed his theory of evolution and confirmed the views of geologist Lyell that the earth itself exists in a state of continuous change.

Ever the reflective young scientist who wondered about the power of natural processes, he ponders the effects of such an upheaval in his home island: "If beneath England the now inert subterranean forces should exert those powers, which most assuredly in former geological ages they have exerted, how completely would the entire condition of the country be changed! What would become of the lofty houses, thickly packed cities, great manufactories, the beautiful public and private edifices?"

In thickly packed Port-au-Prince, Haiti, last month, nature gave its answer.