Did you know that America is home to a staggering 124,000 lakes?
Among them, Lake Tahoe stands out as a remarkable gem. Not only is it breathtakingly beautiful, but it also holds the title of being the third oldest lake in the world.
Located in the Sierra Nevada mountains, this stunning body of water spans 191 square miles and is the oldest freshwater permanent lake in North America.
The Age of Lake Tahoe
According to geosciences professor Winnie Kortemeier, Lake Tahoe is at least 2.3 million years old.
For nearly twenty years, Kortemeier has dedicated her research to uncovering the mysteries of this ancient lake.
Recently, she shared her findings in a presentation where she created a global timeline comparing Tahoe with other historic lakes.
“It’s just really hard to date a lake,” she remarked. “But in Tahoe, it’s very clear what the age of the lake is. It has to be older than 2.3 million years.”
Tracing the Lake’s Origins
Kortemeier’s journey began by studying volcanic rocks in the Tahoe City area.
Determining the age of lakes is a complex task, but Lake Tahoe benefited from the unique interaction between lava flows and water, allowing the rocks to be dated.
She collected volcanic samples from various locations, including Skylandia Beach and Eagle Rock.
In 2012, after sending five rock samples to the U.S. Geological Survey for radiometric dating, she discovered evidence of lava flows occurring in the Tahoe Basin at three significant points: 2.3 million, 2 million, and 920,000 years ago.
This discovery indicated that Lake Tahoe had already formed during these volcanic events.
Setting the Record Straight
There’s a common myth that Clear Lake is the oldest lake in North America, but Kortemeier’s research dispels that idea.
Her examination of continuous lake sediments at Clear Lake reveals it to be only 480,000 years old, significantly younger than Lake Tahoe.
To her surprise, her findings positioned Tahoe as the third oldest lake on the planet.
“It’s number three in the whole world, because it’s really rare to have a lake form this way,” she noted.
The World’s Oldest Lakes
When it comes to the oldest lakes, Lake Baikal in Siberia takes the crown, estimated to be between 5 million and 10.3 million years old.
Lake Tanganyika in East Africa comes in second, aged between 8 million and 10 million years.
These two lakes share a similar formation process, having been created by faults, a rarity compared to lakes formed by glacial activity.
Unique Characteristics of Tahoe
All three ancient lakes—Baikal, Tanganyika, and Tahoe—share distinct features as fault line lakes, characterized by their long and narrow shapes.
Lake Tahoe stretches 22 miles long and 12 miles wide, plunging to a depth of 1,645 feet, making it the second deepest lake in the U.S. after Oregon’s Crater Lake.
As Kortemeier explained, the oldest lakes typically exist within active fault basins.
“Even if you put sediment in it all the time, the bottom is still being dropped down, and so the basins continue to deepen over time,” she clarified.
The Geological Dance of the Basin
The Tahoe Basin is laced with fault lines that contribute to its varying depths.
Over millions of years, the Earth’s movements have shaped this unique landscape.
“Nevada, in the last 17 million years, has been stretched twice as wide as it started out,” Kortemeier said.
As the area expanded, the basins dropped along faults, creating the profound depths we see today.
Tahoe’s Remarkable Purity
Interestingly, despite its ancient origins and the volcanic activity it has experienced, Lake Tahoe is considered dormant, not extinct.
It’s renowned for its incredible purity, boasting 99.994% pure water.
In fact, the volume of water in Lake Tahoe is so immense that it could supply every person in the U.S. with 50 gallons of water daily for five years.
If you were to spread all the lake’s water across an area the size of California, it would still be 14 inches deep!
A National Treasure
With around eight million people living within a half-day’s drive of the Tahoe Basin, it remains a popular destination.
Home to twelve ski resorts and stunning views that have graced numerous films, Lake Tahoe is truly a landmark in the country.
It’s not just a lake; it’s the grandfather of American lakes, steeped in history and natural beauty.
So, what’s next for Lake Tahoe? The answer lies in the ongoing research and discovery of its ancient secrets.