Day 4: Mono Lake and the Tufas

Today we went to see Mono Lake in NV (wikipedia). This is a very unique lake to say the least. It is a shallow closed basin, meaning whatever water goes in can only leave through evaporation. Los Angeles has been diverting water from the surrounding creeks that feed water to Mono Lake for decades. So much so, that at one time the creeks all dried up. With no water entering the lake and evaporation removing it, it has become a very alkaline, high pH (10+) lake. It also has a lot of arsenic from the surrounding geology. Needless to say, it is not somewhere you would want to swim!

Of course…microorganisms still live and thrive there! The microbes that live in this water are very unique and provide a great example of how microbial life is like a honey badger, “it doesn’t care”…

The really cool, geologic feature of Mono Lake are what are known as Tufas. These are calcium carbonate deposits that form when calcium-rich groundwaters meet the carbonate-rich lake water, causing a relatively fast precipitation of calcium carbonate. These are in the shape of towers. The lake level has risen and fallen over time, exposing the tufas that originally formed underwater. Up on the sides of the surrounding mountains are evidence of ancient lake levels. Now that LA has drained the lake about 50 ft from the late 1800’s, there are tufas that are along the shoreline and partially submerged in the lake itself. This was a beautiful day and some pretty cool geology to boot!