BY CLAIRE CUDAHY / CCUDAHY@TAHOEDAILYTRIBUNE.COM
Lake Tahoe’s cold, deep waters have long been the source of tall tales about death and hidden secrets. There are stories of bodies dumped by the Mafia floating in its depths, perfectly preserved by the cold temperatures, and others of Chinese laborers who were tied together and dropped into the icy waters to avoid payment for their work on the railroad.
Famed explorer Jacques Cousteau was rumored to have gone scuba diving in Lake Tahoe, emerging from the water only to utter, “The world is not ready for what I have seen.”
The truth about what lies beneath the surface of the second deepest lake in the United States is arguably just as interesting. But to truly understand the intricacies of its underwater world, you have to start from the beginning.
SHAPED BY GEOLOGY
It’s a common misconception that Lake Tahoe was formed by the collapse of a volcanic crater, like Oregon’s Crater Lake. In fact, the basin was formed by the rise and fall of landscape due to faulting.
Over the last two million years, hundreds of earthquakes stemming from three major fault lines have shaped the basin, which filled up with rain, snow and draining creeks and rivers. The lake owes its clarity to the large size of the lake relative to the overall size of the watershed.
A volcanic period then ensued where lava flowed from Mount Pluto, damming up the Basin’s ancestral outlet, the Truckee River, and raising the water level by several hundred feet before another outlet formed, the Lower Truckee River.
Next came the Ice Age.
Glaciers, slow-moving rivers of ice, gouged out huge valleys as they picked up rocks in their paths and piled them into ridges called moraines. The glacial activity is responsible for notable features in the basin like Fallen Leaf Lake, Emerald Bay and Angora Ridge.
“Then about 60,000 years ago there was a massive landslide on the West Shore in McKinney Bay due to a massive shelf collapse,” explained Dr. Annie Kell, a seismologist at the University of Reno, Nevada Seismology Laboratory. “Thousands and thousands of cubic meters of material slide out into the lake. All these giant boulders and rubble you see in that area in the center of the lake almost all the way across, that’s from the slide.”
The landslide resulted in a tsunami that wiped out nearly every living thing close to the lake within 20 minutes.
Animation by Steven McQuinn, excerpted from UC Davis 3-D movie “Lake Tahoe in Depth.
Beneath the surface, this cumulative geological activity created an underwater landscape characterized by steep cliffs along the fault lines and large chunks of rock scattered across the bottom, the longest of which measures almost a mile and the tallest nearly 500 feet.
The West Tahoe Fault, the longest of the three faults, runs along the same path as the Rubicon Trail from Emerald Bay to D.L. Bliss. Over the last 40,000 years, the east side of the fault has dropped over 100 feet, creating a granitic wall the height of a 10-story building.
The Stateline Fault has created an underwater cliff that extends to the deepest part of the lake at 1,644 feet.
Photographer Dylan Silver has captured the underwater landscape of Lake Tahoe at its shallower depths — above 100 feet — for nearly five years.
Though it was the lake’s famous clarity that first drew him to try snorkeling and scuba diving there, he soon found an interest in the unique rock formations on the bottom, which became focal points in the pictures that he sells online and in shops around the basin.
“Most other locations you’re diving because there’s an abundance of life, but in Lake Tahoe, it’s almost the opposite,” said Silver. “There’s a surreal emptiness that’s interesting, but not the same as diving in any ocean or anywhere else. It’s very monotone blue and you get big boulders looming out of that 70- to 100-foot visibility.”