Memories of the Salton Sea, A Unique Geology

Salton Sea Skies - n/a
The 8,717′ Santa Rosa Mountain, seen here in the distance, is more than 50 miles from the southern shores of the Salton Sea.

The basin we know as the “Salton Sink” is one of the lowest places in North America. It rests over the San Andreas Fault system and is in a very active earthquake fault zone. Geothermal energy expresses itself at many locations around this body of saline water.

While the present water body has its origins in a man-made event occurring in the early 1900s, the geologic record shows several iterations of flooding and slow evaporations in recent millennia. While most of the water drained from the northwestern Colorado Plateau finds its way to the Gulf of California, there have been events that led the water to find its way into this basin. Considering the erosion that carved all that sand from the plateau includes the big ditch we call the Grand Canyon, it isn’t hard to imagine that all that sand could build into a berm dam and cause the water to periodically find alternate courses. The bottom of the present day ‘sea’ is about 280 feet below sea level, so water seeking the lowest point was periodically captured here, until the sand berm evolved and directed the flow back to the Gulf of California. These cycles would repeat about every 400-500 years. The most recent natural occurrence was around 1600-1700. Visible wave-cut lines from these huge lakes are present at several locations around the sea, especially at the southern flanks of the Santa Rosa Mountain chain. Previous lakes were more than three times the size of the current one (100 miles by 35 miles), and five or six times deeper (300 feet).

The Colorado River Delta in years past, was an important migratory refueling stop for birds. During the 20th century, a series of dam emplacements along the river redirected most of the flow for ‘civilized’ uses, and the periodic flooding was halted. This resulted in the delta’s viability being compromised. The habitat at the Salton Sea became increasingly important. I hate to imagine what the impact to billions of birds might be were it not for this critically important location.