Some combination of algae and bacteria is periodically turning Iran’s Lake Urmia from green to red. The change typically occurs when summer heat and dryness evaporate water, increasing the lake’s saltiness. Data from satellites indicate that the lake has lost about 70 percent of its surface area over the last 14 years.
Images taken by the Moderate Resolution Imaging Spectroradiometer (MODIS) onboard NASA’s Aqua satellite.
Source: NASA Earth Observatory (http://earthobservatory.nasa.gov/).