The water around Andros Island in the Bahamas has turned a chalky white in the wake of Hurricane Frances in the top image, acquired on September 6, 2004, by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite. The storm churned the ocean waters, bringing white carbonate sediment (chalk) to the surface. As can be seen in the lower image, the waters around the island typically appear to be bright turquoise, an effect of the reflection of the coral on the Great Bahama Bank through the clear, shallow water. After the storm, the chalk-clouded water is even brighter than normal.
NASA image created by Jesse Allen, Earth Observatory, using data provided by the MODIS Rapid Response team at Goddard Space Flight Center