Although dust storms often call to mind the sand seas of the Sahara or the Arabian Peninsula, dust storms also strike South America. Fine sediments—likely a combination of fine sand and glacial flour, or loess—cover much of Argentina, and winds can whip these sediments into dust plumes.
The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite observed a dust storm in the region of San Juan, Argentina, on July 25, 2011. The dust appears to blow northward, and concentrate along the slopes of the Andean foothills in the northwest. In the south, Sa Pie de Palo and Sa de la Huerta poke above the relatively low-lying dust plumes.
Not many source points for the dust are obvious in this image, but some dust appears to blow northward from Pampa de las Salinas, a salt pan. Clouds in the southeast might be related to the same weather system that stirred the dust.
NASA image courtesy Jeff Schmaltz, MODIS Rapid Response, NASA Goddard Space Flight Center. Caption by Michon Scott.