Lake Tahoe, here I come. I have left the crowds behind and am heading to Sierra Nevada — a mountain range that straddles California and Nevada — for the placid lake. I drive for about 40 minutes from Reno (in Nevada), dubbed the “biggest little city in the world” — a reference not to its size as much to its attitude — for my first glimpse of its shimmering turquoise waters.
With a surface area of about 122,200 acres, this is the largest alpine lake in North America. At 6,225 ft above sea level, it is also among the highest lakes in the US. I dip my toes in the lake, while the not-so-timid jump right in, try stand-up paddle boarding, kayaking, windsurfing and an array of other water sports.
But even as I look at this vast expanse of blue-green, I want to learn more about the lake, how it was formed, what lies beneath and the life it sustains. My local friend, Naomi, suggests a trip to the Tahoe Center for Environmental Sciences, which sits within the Sierra Nevada college campus in Nevada.
This is a centre that breaks all clichés and makes learning a whole lot of fun with the use of interactive technology. Donning 3-D glasses I soar over the lake and then go underwater, without getting wet! A booming voice dubs me an Earth scientist, while the video explains how the lake was born.
It goes back over 2 million years. The lake, I learn, emerged out of geological faulting. Think of faulting as a fracture on the Earth’s crust that causes mass rock movement. Uplifting fault blocks led to the creation of jagged peaks while the rocks thrown down created a large valley. This movement, incidentally, continues even today, as California tears away from Nevada, extending the Earth’s crusts and changing the shape of the lake.
Various earthquakes shaped the basin. Erosion and, eventually, glaciation — the process of being covered by ice sheets — added the finishing touches, as water from rain, snow and streams (there are 63 today) flowed into the basin, creating Lake Tahoe.
But what would the lake look like if the fault lines had appeared just a little further north or south? I make it happen with a sleight of hand, courtesy an interactive sandbox. Augmented reality allows visitors to change the topography by simply digging their fingers into the sand in the exhibit. I create mountains and watch the water find a new channel.
The box drives home the point that water shapes, and is shaped by, the landscape. With a flick of my wrist, I can bring about a rain shower in the sandbox. Little wonder then that this interactive exhibit is a hit with kids and brings out the child in all of us.
I then check out the lake’s residents. In an aquarium of her own is Lahnie, the Lahontan cutthroat trout, Nevada’s state fish. The largest of the cutthroat trout species, Lahnie is rather intimidating, even behind the glass. Once the most feared predator in Lake Tahoe, Lahnie and her relatives lost out to commercial overfishing, combined with habitat change. Efforts are on to bring the trout back to where it belongs.
Two other aquariums showcase a host of native and non-native species. I see the bluegill, also known as the ambush predator because this iridescent little fish darts out from behind a thick mass of plants and catches prey by surprise. I look right into the mouth of a largemouth bass, which is good at swallowing big prey, while the little ones simply slip out of the wide mouth.
But as I look at serene images of the lake and the varied life it sustains, I wonder what we can do to preserve our environment. The answer lies aboard the mock research vessel John LeConte, where a virtual researcher leads the ship. I glimpse the Secchi disk, an instrument used for measuring water clarity.
Between 1968 and 1997, deep water clarity declined by 30 per cent, from 100 to 64 ft. One of the major culprits was vehicle exhaust; pollutants change the pH balance of lakes and this, in turn, affects its inhabitants. The simplest of measures — opting for public transport or using a bicycle, for instance — can go a long way in protecting a waterbody.
As a visitor, I wonder what impact, if any, my actions would have on this lake. On cue, I notice topographical sketches of the lake, and see how streams join together to create the waterbody. It reminds me that we too are connected, even if we may be air-miles away.
Kiran Mehta is a journalist based in Mumbai