The blinding sandstorms that slowed U.S. troop movements in Iraq on Tuesday may be at least partially the soldiers' own making, according to scientists familiar with desert conditions.
"There have been dust storms there since time immemorial," said Farouk El-Baz, a desert geologist who studied the effect of the 1991 Persian Gulf War on the Kuwaiti desert. "It is bad without the military, but military activities exacerbate it."
The dust and sandstorms, which are an unavoidable part of life in the Iraqi desert, are a consequence of destruction over the centuries of a top layer of pebbles, known as desert pavement. The surface is nature's way of preventing erosion and keeping the fine particles of sand and soil in place.
"Every time you remove some of this pavement for any reason, even for innocent things like agriculture, new dust storms and sand dunes are created," El-Baz said.
Warfare is a prime foe of desert pavement. Tanks and armored personnel carriers tear up the surface. The trenches and berms soldiers build for protection similarly devastate the fragile land.
Scientists believe that it takes hundreds of years for the desert pavement to repair itself. So the destruction caused by the war will have consequences far into the future.
Once the protective pebbles are disturbed, fine-grained clay or dust is exposed to the harsh desert winds.
"There is a concern of increased dust emissions from areas impacted from military activities," said Eric McDonald, an associate research professor at the Desert Research Institute in Reno. McDonald has worked with the U.S. military on trying to assess the damage to desert training grounds in California.
Steve Wells, president of the Desert Research Institute, said the intensity of the current dust storms in Iraq "probably doesn't have much to do with destruction of desert pavements, but I can't say for sure."
The fine particles blowing around in broad dust storms can come from great distances away, he said. "A lot of this dust is from loose settlements that exist in deserts already," he added. "Not all surfaces are covered by desert pavement."
Other experts said the dust stirred up by military movements may contribute to the dust storms, but in a relatively minor way.
Military activity "would increase the amount of dust in the air," said Ted Maxwell, a geologist and associate director for collections and research at the National Air and Space Museum in Washington. "I doubt that it would be a factor in comparison with the natural dust storms and sandstorms."