Green and tan shades show the extent of the water in Lake Urmia (also Orumiyeh or Orumieh) in western Iran. The lake is highly saline and only a few tens of meters deep even at high water. The shoreline appears as a white margin of salt. The lake is one of the largest in the Middle East, measuring 130 kilometers (80 miles) from the northern shoreline to the vegetated delta.
Rivers that flow into the lake appear as narrow green lines, especially on the southeastern lake margin (image top right). These rivers form deltas marked by clusters of green agricultural fields; soft soils and the nearby water supply support farming in an otherwise dry region. The lake and its wetlands have been declared a UNESCO Biosphere Reserve.
The city of Urmia stands out as a distinct gray patch surrounded by fields. On the opposite shore, an extinct volcano appears as an oval shape. A causeway and bridge connect the shorelines at this point.
The lake has been experiencing a drastic loss of water and now holds only 5 percent of its known high-stage volume. The drying is vividly illustrated by the fact that the volcano used to be entirely surrounded by the lake. The drop in water levels is related to a long-term decrease in rainfall and the extraction of water for farming. The progressive drying of the lake since 1984 is shown in this sequence of still images.
Astronaut photograph ISS040-E-17264 was acquired on June 23, 2014, with a Nikon D3S digital camera using an 80 millimeter lens, and is provided by the ISS Crew Earth Observations Facility and the Earth Science and Remote Sensing Unit, Johnson Space Center. The image was taken by the Expedition 40 crew. It has been cropped and enhanced to improve contrast, and lens artifacts have been removed. The International Space Station Program supports the laboratory as part of the ISS National Lab to help astronauts take pictures of Earth that will be of the greatest value to scientists and the public, and to make those images freely available on the Internet. Additional images taken by astronauts and cosmonauts can be viewed at the NASA/JSC Gateway to Astronaut Photography of Earth. Caption by M. Justin Wilkinson, Jacobs at NASA-JSC.
The Great Salt Lake of northern Utah is a remnant of glacial Lake Bonneville that extended over much of present-day western Utah and into the neighboring states of Nevada and Idaho approximately 32,000 to 14,000 years ago. The north arm of the lake, displayed in this astronaut photograph from April 30, 2007, typically has twice the salinity of the rest of the lake due to impoundment of water by a railroad causeway that crosses the lake from east to west. The causeway restricts water flow, and the separation has led to a striking division in the types of algae and bacteria found in the north and south arms of the lake.