Tuesday, January 01, 2019

Salton Sea

The Salton Sea is a big, salty lake and occupies a broad low spot in the bottom of the Imperial Valley. The lake surface is currently around 237' below sea level and the bottom of the lake is almost as deep as Badwater Basin in Death Valley. Like Death Valley and the Great Salt Lake and the Humboldt Sink, this is an internal drainage - water flows in but does not flow out. It just evaporates very slowly, leaving mud and salt behind.

The current lake was a bit of an accident, since it formed in 1905 when an irrigation canal went wrong and allowed the Colorado River to flow in. On the other hand, the Colorado had apparently been doing this on its own every few hundred years long before that (perhaps aided by movement during large earthquakes on the San Andreas Fault, which runs along the east side of the valley), so the lake itself has plenty of precedent.


Much of the shoreline is salt and mud, but there are also small shells and lots of fish parts. Which form a sufficiently granular substrate that waves can turn them into something interesting. Here, at the jettied mouth of this small harbor/estuary(?) waves have formed a nice little beach with diverging spits. There were multiple scarps and beach berms, reflecting slightly different water levels and slightly different wave regimes, along with washover fans where larger waves had carried shells over into the lagoon.

In putting together this post, I discovered another blog - Salton Sea Walk - which provided a lot more background on the lake's beaches. It confirmed my suspicion that the shells are probably small, thin-shelled barnacles, but apparently, they are far more abundant on other parts of the lake and a major beach-forming material. Maybe next trip...

Farther up the "beach" there were some faint beach ridges, recording higher levels of the gradually retreating lake (more rapidly in recent dry years).

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