University of Colorado biogeochemist Jason Neff was working on a geological mapping project in Canyonlands National Park in Utah for a period of weeks a few years ago. “Some days we could see for a hundred miles, literally,” he said. “And on other days we couldn’t see for five.” Neff was interested in what was causing the phenomenon, and he set out on a research project on dust in the West that was published earlier this year. He wanted to find out whether the dust in the air was a recent phenomenon or if it was a natural part of the desert atmosphere. He spoke about his research to a group at the Center for Environmental Journalism in Boulder last week.

With a team of other scientists, he took core samples from the sediments at the bottom of alpine lakes in Colorado’s San Juan Mountains; these lakes are downwind from most of the major deserts in the United States. The core samples let him and his colleagues analyze depositions over the past 5,000 years. What they found was startling; in the past 150 years, the amount of dust falling in the alpine lakes was 5 times greater than the average over the past 5,000 years. The study found an enormous spike in the amount of dust immediately following the Pacific Railway Act of 1862, which ushered in the era of settlement and grazing in the West. Neff believes that it is the overgrazing of arid public lands (and most of the West is federal land) that has broken up fragile soils and led to the dramatic increase in soil erosion and resulting dust in the air. “Dust storms are a big issue out there; sometimes they close down I-70 in Utah,” Neff said. “People tend to think it’s just part of being in the desert, but it’s similar to what was happening during the Dust Bowl years in the Midwest.”

The impact on visibility in national parks — an irritant to tourists and residents — is the least of the problems caused by the dust, which carries pollutants, viruses and bacteria, as well as fine particles of clay and silt. Huge amounts of top soil are lost and other impacts range from human health (respiratory difficulties) to increased rates of snowmelt in the Rockies in spring (Dust storms in February often turn whole ranges from pristine white to dingy brown). The report, released in February, made national headlines because the summary pointed out that the West is 500 percent dustier than it was before settlement. Neff said Saturday Night Live’s Weekend Update segment parodied the report by suggesting the increased dust was due to a dramatic surge in Hummel figurine collecting.

This entry was posted on Tuesday, October 14th, 2008 at 8:00 am and is filed under environmental, national parks. You can follow any responses to this entry through the RSS 2.0 feed. Both comments and pings are currently closed.