Imperial Valley, California
by Robb Campbell, U.S. Geological Survey
The Salton Sea first became a lake in 1891; it covers approximately 930 sq
km and lies 70 meters below sea level. Having no outlet, the Salton Sea is
being contaminated by runoff water containing a mixture of agricultural,
industrial and municipal wastes. Approximately four million tons of salt
are transported to the lake each year. The Mexican city of
and the U.S. city of El Centro grew significantly between 1973 and 1992.
The U.S./Mexico border is clearly visible in the Landsat images;
agricultural practices such as field size, use of irrigation, and the use
of herbicides and pesticides, create different field colors and patterns
on the two sides of the border.
1973 image (23 May / 9 June, Landsat 1 MSS, RGB = infrared red green)
1992 image (30 June, Landsat 4 MSS, RGB = infrared red green)
Note: The two 1973 scenes are mosaicked together.
|LM1041037007316090|| 9 June 1973||41||37||MSS|
|LM1042037007314390||23 May 1973||42||37||MSS|
|LM4039037009218290||30 June 1992||39||37||MSS|
Map of the region
From 1:1M USGS map Los Angeles (International Map of the World, 1947)