This detailed astronaut photograph highlights the southern Mingachevir Reservoir in north-central Azerbaijan. Folded layers of relatively young (less than 5. 3 million years old) <a href="//commons.wikimedia.org/wiki/Sedimentary_rock" title="Sedimentary rock">sedimentary rock</a>, explosive volcanic products (ash and tuff), and unconsolidated sediments form the <a href="//commons.wikimedia.org/wiki/Category:Gray" title="Category:Gray">grey</a> hills along the northern and southern shorelines of the reservoir (image centre and right). <a href="//commons.wikimedia.org/w/index.php?title=Afternoon&amp;action=edit&amp;redlink=1" class="new" title="Afternoon (page does not exist)">Afternoon</a> <a href="//commons.wikimedia.org/wiki/Sun" title="Sun">sun</a> highlights distinctive parallel <a href="//commons.wikimedia.org/wiki/Category:Patterns" title="Category:Patterns">patterns</a> in the hills that are the result of <a href="//commons.wikimedia.org/wiki/Water" title="Water">water</a> and <a href="//commons.wikimedia.org/wiki/Wind" title="Wind">wind</a> erosion of different rock layers exposed at the surface. The nearby city of Mingachevir (left) is split by the Kur River after it passes through the dam and <a href="//commons.wikimedia.org/wiki/Hydroelectric_power" title="Hydroelectric power">hydroelectric power</a> station complex at image top centre. The reservoir held approximately 15 billion cubic meters of water at the time this image was taken, with a total engineered capacity of 16 billion cubic meters. The width of the reservoir illustrated here is approximately 8 kilometres; a <a href="//commons.wikimedia.org/wiki/Category:Jet" class="mw-disambig" title="Category:Jet">jet</a> flying over the reservoir left a <a href="//commons.wikimedia.org/wiki/Contrail" title="Contrail">contrail</a> midway between the shorelines.
ISS Expedition 23 crew
<a rel="nofollow" class="external text" href="http://earthobservatory.nasa.gov/IOTD/view.php?id=44186">NASA Earth Observatory</a>