Inquiring Minds By David Brooks Illustrations by Michael Sloan

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Rock On
Studying moraine debris reveals glacial history

Joe Licciardi, associate professor of Earth sciences, goes a long way to get rocks. But not just any rocks: These academic expeditions involve hiring mule teams to carry the right sort of rocks and sediment over a mountain pass in the Andes nearly three times the height of Mount Washington. Shipped back to Durham, this geologic cargo has led to research results that wound up in the prestigious journal Science and could help cast more light on what's happening to our climate now and what will happen to it soon.

Licciardi and graduate student Jean Taggart '09G were among the authors of the 2009 paper about Peruvian moraines, ridges of rocks and debris left behind by retreating glaciers high in the Andes Mountains. Licciardi and his colleagues traveled to high-mountain valleys near the historic Inca sanctuary Machu Picchu several times, doing fieldwork even as mid-July snowstorms covered their tents and house-sized ice chunks tumbled from glaciers high on the steep headwalls above them.

Material gathered from the moraines is ground down and immersed in strong acids until it becomes purified quartz crystals, which are then analyzed for concentrations of the radionuclide beryllium-10, allowing for the precise dating of moraines from recent history.

The analysis led to a timeline of glacier retreat in the Peruvian Andes approximately 200 years ago, toward the end of the Little Ice Age in the northern hemisphere. Comparing those movements with glacier histories in Europe, North America and New Zealand has revealed complex patterns in glacial events during the last millennium.

Supported by a grant from the National Geographic Society, Licciardi has returned to the Cordillera de Vilcabamba range, collecting not just rocks from the moraines but also sediment cores from bogs located between them. Formed by glacial meltwater lakes that are now filled with sediment, the bogs preserve a more continuous record of how the region has changed; moraines tend to be wiped out by successive expansion of glaciers.

These techniques are still being developed, but they look promising. "It just so happens that our group here and my colleagues at Columbia University were among the first ones to obtain beryllium-10 ages from moraines this young," says Licciardi. "I expect to see more studies capable of doing this, and looking more comprehensively at global patterns of glacier activity during the last few centuries."

Striver vs. Conflictor
What kind of personality archetype are you?

Turning something that seems obvious into real science can be surprisingly difficult, so when Jack Mayer's new graduate student, Mike Faber '06G, '09G, wanted to study the relationship between people's personalities and their cultural preferences—moving beyond the level of online quizzes like "Which 'Lord of the Rings' character are you?"—Mayer was delighted.

"When Mike and I started working together, I was astonished at the breadth of his knowledge about the arts, movies, music, high culture, popular culture—everything," says Mayer, a professor of psychology. "I've always wanted to do a serious test of Carl Jung's ideas. Since Mike has a very rare and deep knowledge, I thought that would make it possible."

The result was the paper "Resonance to Archetypes in Media" in the Journal of Research in Personality. It describes an unusual study that points the way to connect media preferences to personality. It also led to a dissertation and a professorship for Faber, who now teaches psychology at Woodbury University in Burbank, Calif.

Mayer and Faber started with the 13 universal character archetypes similar to those devised by Jung, the founder of analytical psychology, such as heroes, jesters, outlaws and lovers. Part of the appeal of this work, Mayer says, was his desire to test Jung's theory, which is usually rejected or embraced out of hand without much evidence either way. They had 125 participants identify and react to visual and musical pieces from movies, music and classical art; then they statistically correlated these reactions to the 13 archetypes to create a scale that associated them with personality characteristics.

They concluded there were five clusters of archetypes that resonate with people and can help predict their personal media preferences and, more interestingly, life themes. People who preferred compassionate, loyal characters, for example, were associated with the "Carer" archetype cluster. Other clusters and their associated characteristics included the Striver (i.e., preferring competitive and driven characters); the Conflictor (rebellious and destructive); the Knower (wise, mystical or creative); and the Everyperson (independent, honest and carefree).

Faber and Mayer say that the statistical correlation and ability to replicate the study's findings gives it a scientific heft, which means it could give people insight into their personalities and help them make decisions as small as "What movie should I rent?" and as big as "What career should I pursue?" It might also lead to uses in industry, such as making targeted advertising more effective, and in medicine, helping clinicians better understand personality disorders.

"People have been struggling with personality measurement for years," says Faber, "debating how valid a certain test is, how intrusive a certain test is." A mix of Carl Jung, hit movies and statistical analysis might change that.

Tick Sightings
Tracking Lyme disease by satellite from space

Here's an unlikely sounding goal for a research grant: With a satellite and a barometer, count the Lyme disease- infected ticks in your backyard. Allowing for some exaggeration, that's the gist of an intriguing NASA-funded project.

The project is an example of what research assistant professor Michael Palace '06G of the Complex Systems Research Center calls eco-epidemiology, or studying the patterns of disease and illness in the landscape through ecological factors. In this case, the goal is to develop ways to predict where and when Lyme disease occurs, says Palace, "without having to go out and set 100 traps in the field" to count infected ticks. Instead of traps, the project is looking at a multitude of variables to see if combinations of temperature, weather, forest cover or other factors can be correlated to estimate how likely it is that you'll encounter disease-ridden ticks in a given place and time. "We're looking at anything that we can pick up so we know where the disease might appear, when it might appear," says Christina Czarnecki '11G, lead research scientist.

Students, professors and others have spent two years gathering ticks at 40 sites in southern New Hampshire by sweeping white felt "tick flags" across the ground over predetermined set transects,  then having the state health lab analyze the tiny arachnids for Lyme disease. Roughly half of all the adults and nymphs carried the bacterium, Borrelia burgdorferi, which causes Lyme disease, a reflection of how much the disease has spread in New England.  

Field workers also gathered information about temperature, humidity, soil moisture, canopy cover and other factors that might affect tick populations. Perhaps the most intriguing part of the work is that the project also examines images taken by satellites that indicate forest density and patchiness, because ticks are happiest when it's not too shady and not too hot. Czarnecki, along with Applied GeoSolutions of Newmarket, N.H., is using geographical information systems and remote sensing to correlate satellite data with ground observations.

Statistical analysis of the 2009 data was done with the help of math professor Ernst Linder, who teased out which data points produced real correlation and which were noise. So far, three indicators have been found to point to tick abundance. Two involve measures of how development has broken up woodlands, which wasn't a surprise. The third factor does raise eyebrows, however: soil moisture. This is apparently a reflection of weather, since the wrong temperature or humidity sends ticks scurrying for cover, where they can't grab your leg as you walk past.

Palace hopes to win more grants to continue the project. As an incentive to funding agencies, he notes that predicting the presence of ticks or disease-causing organisms can be valuable for tracking many maladies, such as Nantucket fever, Rocky Mountain spotted fever and Chagas disease. He believes this approach could be adopted more widely, as remotely sensed satellite data linked to measurements in the field becomes more common. Perhaps weather forecasts will one day include a tick forecast alongside pollen and pollution predictions.