GeoSnaps - Image of the Day
Geologic snapshots capturing Arizona’s geologic setting and mining history with a picture of the day from 1 January through 31 December 2013.
Check out previous GeoSnaps/Images of the Day.

Spring-Summer 2010 | Lake Mead, Arizona – Nevada | This Envisat image features the manmade Lake Mead, located east of Las Vegas (visible) and west of the Grand Canyon along the border of the US states of Arizona (bottom, east of river) and Nevada (the rest). Lake Mead was established in the early 1930s by the construction of the Hoover Dam on the Colorado River (bottom). The Hoover Dam (green area between the lake and river) was one of the first of some 45 000 major dams to be constructed on rivers worldwide.
This image was created by combining three Envisat radar acquisitions (15 May, 19 June and 24 July 2010) over the same area. The colours result from changes in the surface that occurred between acquisitions. From ESA's "Space in Image" collection.