What Lies Beneath....Lake Tahoe

Lake Tahoe in Springtime

 If anyone has ever told you, "Go jump in a lake," I know just the place to go!

A beauty and a wonder...

There are, of course, the five great lakes (Michigan, Huron, Eerie, Ontario, and of course, Superior). These interconnected fresh-water lakes serve as a partial border between Canada and the United States, connecting to the Atlantic Ocean via the Saint Lawrence River. Twenty-one percent of the world's fresh water is contained here. Now, those are indeed great lakes. But if you don't make the famous five in the Northeast, what have you got?

A chilly morning

Blue skies, clean air

Well, head about as far south and west from the Great Lakes as you can go, and you will find yourself on the border between California and Nevada. Coming in at number 6 when measured by volume, Lake Tahoe is a pristine, clear version of American fresh water lake. So clear, in fact, on most days, you can peer over 20 meters deep into this prehistoric wonder. But I recommend looking from the surface, as the crystal clear water has an average spring temperature just above 40 degrees. Brrr.

Lake Tahoe is admired for its beautiful alpine surroundings, and quiet living. Okay, yes, South Lake Tahoe does have its share of casinos (and a couple on the North side as well), but because the terrain is quite mountainous, human activity has been fairly limited -- hence the clarity of the water.

So, in the midst of the recurrent drought theme in California, one might well ask, where did all this water come from? Two-thirds of the Tahoe basin belong to California, so the question is important. The answer will take us way back in time....

Geologic Drama

To begin, Lake Tahoe is situated at approximately 6,225 feet -- or over a mile above sea level. Take that mile-high city! And it's deep -- almost a third of a mile. Second-only in depth in North America to Crater Lake. And, it's old -- but she looks good for her age. Lake Tahoe was formed about two million years ago and has been carved into its current shape by the ice ages. The area surrounding the lake is primarily national forest land, so the panorama of surrounding mountains can be breathtaking, as well as protective of this natural resource.

The Tahoe basin was formed by vertical faulting. The uplifted blocks created both the Carson Range on the east and the Sierra Nevada crest to the west. For those of you poor souls who do not have the privilege of calling California home, sierra is Spanish for mountain range, and nevada, contrary to popular belief, does not mean casino. Nevada is Spanish for snow-covered, and the mountains surrounding Lake Tahoe live up to their name -- just ask the Donner party.

But we digress. There are three principal faults along the Tahoe basin, and evidence exists for paleoearthquakes. The most recent earthquake appears to have occurred between 4,000 and 4,500 years ago. But before you relax, evidence in the landslides in the area suggest that these earthquakes occur in three to four thousand year intervals. So, any time now, right?

If that is not enough geologic drama for you, it was the eruptions from the volcano, Mount Pluto, which formed a dam on the north side of the basin, allowing the lake to form. As melting snow filled the basin to form the ancestral Lake Tahoe, rain, run-off, and glaciers would continue to add to the lake.

Now I realize that we here at J and L get excited about unusual things, but because of the great depth and sheer volume of water within the lake, the faults which created this valley, can also trigger tsunamis. Wave heights are predicted to reach over thirty feet and could traverse the lake in mere minutes. Geological evidence suggests that a massive collapse along the western edge of the lake occurred 50,000 years ago, creating McKinney Bay and generating a tsunami exceeding three hundred feet in height.

The Washoe Tribe of Native American Indians inhabited this area for over a thousand years. Lake Tahoe is now home to gamblers, recreation-seekers, and the well-heeled. But, if you are willing to live on the edge of this geologic wonder, there is something for everyone, every season of the year. From skiing to swimming, from hiking to camping, there is a sport, and a spot here, to appeal to everyone. So, go jump in a lake -- but wait until August when the water temperature hits 65.