The image of vast desert sand dunes evokes a sense of wonder in many of us. After all, this is the world of Ali Baba and his forty thieves; of caravans of camels laden with exotic riches; and of shimmering mirages that entice the delirious traveler. It is a world of illusion, secrecy, and mystery.

But, it’s not an illusion. It’s all quite real, as evidenced by the fact that sand dunes are found in nearly every part of the world, and range from a couple of hundred square feet to dune fields the size of Texas. However, there are secrets hidden in the dunes; secrets to the geology, environment, and climate of ages past. And there is mystery, too, in the way these enduring, yet ever-changing landforms, accumulate, shift, and migrate. Yes, if the dunes could speak, they would teach us plenty.

It is with more than a hint of disbelief that Lancaster admits he’s been studying sand dunes for nearly three decades, uncovering the dunes’ secrets and mysteries in a purely scientific quest. "I suppose it all began in the Kalahari, back in 1972," Lancaster says. His early work, focused primarily on what those sparse dunes told about climate change, so piqued his interest, he earned his Ph.D. in Geography from the University of Cambridge. Then he looked even further. "I decided I wanted to see some real, serious sand dunes," he explains. "So we took a summer vacation to Namibia and fell in love with the place." The Namib desert extends some 1200 miles along the Atlantic coast of southwest Africa. Its entire southern half is a vast expanse of sand, where dunes stretch up to 20 miles long and rise to heights of up to 800 feet. That summer vacation so entranced Lancaster that it led to three years at a Namibian research station, mainly investigating how dunes formed in different wind regimes.

It was the beginning of a career that has established Lancaster as the world’s foremost expert on desert sand dunes. Since then his studies have taken him to the world’s most immense deserts, including Africa’s Sahara, the Mojave and Sonoran Deserts of North America, and even to Antarctica, where, he assures us, there really are sand dunes. "I’m quite sure I’ve stood on the Earth’s southernmost dunes," he quips. "I’ve got the pictures to prove it." He’s even looked at dunes on Mars—although he didn’t get to visit—using Viking orbiter images to estimate the volume of sand in that planet’s North Polar Sand Sea.

Lancaster’s dune research falls into three broad categories: past, present, and future. He studies the buried sediments of the dunes to find clues to what the climate of an area might have been like thousands of years ago. Of equal importance, he examines the dynamics of dune formation to understand the complex processes that create them. And, he applies that knowledge to help predict where dunes might form in the future, or how they may migrate from current locations.

Lancaster’s first work in the United States focused on the past. "North America doesn’t have many active dune areas, so I started to look at the history of the dunes in the Gran Desierto of Mexico and the Mojave Desert in the American Southwest." One way of uncovering a dune’s history is to literally uncover the many layers of buried sediment beneath its surface. The age of those grains of sand, perhaps buried for hundreds of thousands of years, can then be determined by a process known as luminescence dating. "By dating and examining the composition of sediments," explains Lancaster, "we build up a picture of the history of the dune, which we can then tie in with what we know about the climate history of the area." This helps shed light on past geologic events, like earthquakes or volcanoes, or the ancient climate shifts that may have contributed to the initial formation of the dunes.

Lancaster’s most recent probes into dune history occurred last year in two areas: the United Arab Emirates on the Arabian Peninsula; and, the Sahara region of Mauritania in Western Africa. He and an international contingent of researchers, including scientists from India, Great Britain, Canada, and France, studied the way dunes in these two areas have responded to climate and sea-level changes over the past centuries. During three weeks in the United Arab Emirates and two weeks in Mauritania, they sampled and made detailed observations of sediment types in the dune areas. Their work on the Arabian Peninsula was made immensely simpler, says Lancaster, by the onslaught of progress. "At the time, they happened to be building a two-lane highway across the particular stretch of dunes we were interested in. They do that kind of thing all the time there. Thanks to their bulldozers, we were given access to layers and layers of sediments, and we got much more out of the trip than we really expected." They were not so fortunate in Mauritania, a country where, in some regions, pack animals remain nearly as important as trucks for transportation. "There, I’m afraid, we had to do our own digging," notes Lancaster.

For his studies of dunes in the present, Lancaster has been able to stay much closer to home. Since 1992, he and two colleagues, Cheryl McKenna Neuman of Trent University, and Bill Nickling of Canada’s University of Guelph, have spent part of each spring at the dune fields around Silver Peak in southwestern Nevada. Here they have studied fundamental dune processes and contributed greatly to the basic understanding of these landforms. At Silver Peak, Lancaster, Neuman, and Nickling were the first to use sand traps to capture and measure moving sediments. Now widely used, the method has proven much more accurate than sediment transport estimates based on wind data.

Another way of looking at sediment transport entails viewing it from afar. Lancaster reports that radar and satellite imagery have become valuable tools in studying dunes. "Basically, satellites can be used to identify different areas of dune types and what types of sand they are made up of," he says. "We can actually track the movement of sands from space as well." This distant view helps make a more accurate determination of the sources of blowing sediments, and provides a valuable, and otherwise impossible, sense of perspective. "Working in a North American desert, or even Namibia, does not prepare one for the vastness of a place like the Sahara," Lancaster notes. "It just goes on and on. There would be no way to really comprehend it without a satellite to set you back and allow you to see the big picture."

In addition to shedding light on the dunes of yesterday and today, all this knowledge helps predict when, where, and how dunes may form in the future. As eerily beautiful as a giant sand sea may be, one need only think back to the dust bowl years of the American Midwest to appreciate the destructive power of wind and sand. Based on his years of research, Lancaster has developed what he calls the Dune Mobility Index, or DMI, to help make predictions about the movement and formation of dune areas. "It’s very simple really," Lancaster explains. "Basically, the movement of dunes is directly proportional to the presence of strong winds and inversely proportional to the presence of vegetation." Simple perhaps, but valuable enough that the United States Geological Survey has used Lancaster’s DMI to help predict the effects of climate changes in the high plains. In the future, Lancaster envisions tying his DMI into a global climate model and applying it on a large scale. This will help refine scientists’ understanding of global climate change, and help predict where encroaching deserts might threaten human livelihood.

Moving sand and dust, and how to stop them, are the focus of another of Lancaster’s ongoing projects. This study is at Owens Lake, in southeastern California, where dust problems have plagued the area for decades. Lancaster has joined other DRI researchers working in the area to examine how sand transport contributes to the problem, and the possible benefits of introducing vegetation. "This is a case where our research may be able to help fix a very real problem," says Lancaster.

Over the years, Lancaster’s work has been widely recognized by the scientific community, and his professional honors include DRI’s Dandini Medal of Science and a Distinguished Career Award from the Geomorphology Speciality Group of the Association of American Geographers. However, Lancaster will soon receive exposure not often experienced by scientists, when he appears in an upcoming Discovery Channel documentary on deserts. The first segment of the three-part program, filmed in Sand Mountain, Nevada and Chinguetti, Mauritania, focuses on the physical environment of the desert. Lancaster hesitantly concedes, "I’m sort of the star of that part."

Stardom or not, the photographs that line Lancaster’s walls, and the intensity with which he speaks, attest to a man enthralled by his work. Though he’s studied them for years, perhaps Lancaster’s fascination stems from his own sense of the dunes’ wonder and mystery. That should keep him going another few decades.