Far below I can see Lake Manasarovar, described by Swedish explorer Sven Hedin a century ago as "an enormous turquoise embedded between two of the finest and most famous mountain giants of the world," Kailash and Naimona'nyi. This stunning tableau, about 10 miles from Nepal and 20 miles from India, is among the world's most sacred landscapes. According to Hindu and Buddhist belief, this is the center of the universe, and four great rivers are said to flow through subterranean passages. This is figuratively true: four of Asia's most important waterways—the Indus, the Sutlej, the Brahmaputra and the Ganges—are fed by the snow and ice fields of this mountainous region.
As we set up our tent for the night, I feel pressed in upon by walls of gray, unstable rubble, the legacy of some long-ago era when the ice here was advancing rather than retreating. We awake to see the sun starting its slow pan across our deep, dark valley. It will be at least another hour before the glacier-fed stream below throws off its frozen quilting. Pulling on layers of fleece, Thomas and I join the others for breakfast. Between sips of steaming tea, I study Thompson.
Now 58, he seems little changed from the man I first met a decade ago, though his brown hair has grayed and his asthma, which was diagnosed some 15 years ago, sounds a little worse. Of medium height and build, he's not physically imposing. But he possesses nearly superhuman determination and drive. The second child of three, Thompson spent his formative years on a small farm in Gassaway, West Virginia. Neither of his parents went beyond the eighth grade, though his mother later earned her high-school equivalency. The family struggled financially, even before Thompson's father, an electrician, died when Lonnie was in high school. At one point the young man held four jobs to bring in needed income. In 1966 he won a scholarship to West Virginia's Marshall University, where he majored in geology. There he met Ellen Mosely, a petite physics major who went on to get a PhD in geography; she is Thompson's scientific partner, and they've been married for nearly four decades.
Though it has taken many years, honors and prizes are flowing Thompson's way. This summer, he will be awarded the National Medal of Science by President Bush. But Thompson's lifestyle remains simple. He and Mosely-Thompson still live in the unpretentious white-frame house they bought a quarter century ago in Columbus, Ohio; their daughter, Regina, an FBI agent, and her husband live nearby. For exercise, the Thompsons walk their small dogs, Russ and Kino, in a little park down the street.
Initially, Thompson says, he wanted to become a coal geologist, combining his interest in earth sciences with a desire to make a good living. Glaciology did not attract him at all. "I can remember studying glaciers [at Marshall] and thinking to myself, what a waste! Glaciers take up only a very small percentage of the surface of the earth; they're in really remote areas where people could not care less about what happens, so why in the world would anyone take the time to study them?" After a brief stint in the National Guard, Thompson enrolled in 1972 as a graduate student at OSU and, to defray expenses, hired on as a research assistant at the university's Institute of Polar Studies. He soon found himself staring at the first deep ice core ever retrieved from Antarctica. It was a revelation.
For those who can decipher its arcane script, ice has fascinating stories to tell. Fluctuations in various isotopes, or atomic forms, of oxygen document swings between warm and cold epochs; fluctuations in nitrate levels mark how plants respond to the expansion and contraction of ice. Ice contains bubbles of air from ancient atmospheres and layers of ash from long-ago volcanic eruptions. It contains layers of windblown dust that yield information about broad shifts of precipitation, rising during dry epochs and falling during wet. And ice records shifts of precipitation in the form of thicker and thinner annual layers.
For a long time, glaciologists gave little thought to the high-elevation ice of the lower latitudes. (At about 30 degrees of latitude, Naimona'nyi falls within the near tropics.) The scientific action, it was all but universally assumed, lay in the dramatic expansions and contractions of the great ice sheets in Antarctica and Greenland. Besides, most scientists assumed that ice anywhere close to the Equator would have melted and refrozen many times, erasing any history written in its layers.
Two years before getting his PhD, Thompson accompanied Ohio State geologist John Mercer on an exploratory expedition to Peru's Quelccaya ice cap. Mercer had the idea that it might tell him whether major advances of ice in the Northern and Southern hemispheres occurred at the same time. It was a problem that also interested Thompson, who was then comparing dust layers in ice from Antarctica and Greenland.
Which is why, in the summer of 1974, Thompson had his first encounter with the dazzling expanse of white that would change his life forever. Some 18,700 feet high, the huge Quelccaya ice cap extended over 22 square miles. But what enthralled him was its dramatic western face. It looked remarkably like a 180-foot-high wedding cake, with layers of pellucid ice alternating with layers darkened by dust. Had Quelccaya ever melted, Thompson realized, those sharply delineated layers would have collapsed into homogenized slush.
It was the start of an epic struggle to study the ice cap, one that many predicted Thompson would lose. "Quelccaya is too high for humans, and the technology [to drill it] does not exist," Denmark's Willi Dansgaard, one of the titans of glaciology, famously observed. Indeed, Thompson's first big expedition to Quelccaya, in 1979, ended ignominiously when the Peruvian pilot commissioned to airlift the heavy drilling equipment grew nervous about high winds and backed off. Before Thompson returned to the ice cap, he applied to Ohio State's MBA program. If he came back empty-handed again, he had decided, he would quit glaciology and apply his talents elsewhere. "And probably," he says today, "I would have made a lot more money."