A dust storm blows off the coast of Alaska in this orbital view from a NASA satellite.

NASA’s Aqua satellite snapped this image on Nov. 1, 2006 almost one year to the day of a massive dust storm that washed over the same region. Dust from glacial sediments in Alaska’s Copper River Valley is the source of the material seen here streaking across the dark water.

Also known as loess, glacial sediment forms as glaciers slowly move over land, grinding the rocks below them into a fine silt that can form dust, and even dunes, along Alaska’s river valleys. The region’s Chinook winds, also know as foehn, and then push the sediments towards the sea.

In this view, taken by Aqua’s Moderate Imaging Spectroradiometer (MODIS). If you look close, you can see the dust actually turning corners, which occurs as wind direction changes as it blows through the valleys.

-- SPACE.com Staff

Credit: NASA image courtesy Jeff Schmaltz, MODIS Rapid Response Team, Goddard Space Flight Center.