The things they carry are large and small, and their actions are earth-shattering, to say the least. They are unstoppable forces of nature that move slower than a sloth. I don’t mean my family of 20 Indians, but rather the things that those 20 people traveled all the way to western Canada to go see: glaciers!
A glacier is a gigantic moving slab of ice, and it is responsible for that jaw-dropping scene above (#nofilter). Not exactly something you’d see in hot, humid, flat-as-a-flounder Houston, TX.
A little background: my family loves road trips. We’ve driven through 37 of the 50 states and visited countless national parks, monuments, preserves, historic sites, etc. Having enlisted the families of her sister and first cousin, my mom decided on our most ambitious voyage yet: the True North.
About 145 kilometers west of Calgary lies Banff National Park of Canada, as well as adjacent Jasper National Park, Kootenay National Park, and Yoho National Park. Known for their spectacular waterfalls, massive ice fields, and gorgeous lakes, these are the most visited national parks in Canada. They didn’t disappoint.
A glacier begins in an ice field, which is typically located in a place where snow and ice accumulate faster than they melt. A helpful tourist in Jasper explained ice fields and glaciers to our family in terms of lakes and rivers. Just like a river can branch off of a lake and continue flowing across the land, glaciers are pushed off from ice fields and move slowly but surely over time.
As the glaciers move across the mountains in the Canadian Rockies, they wear down the rocks and earth they pass over. The product of this erosion is an especially fine dirt called rock flour. The individual pieces that make up this rock flour can have a diameter as small as 2 microns! This silt is left behind as a remnant of the glacial motion and is often carried by the glacial meltwater into the many lakes that dot the Canadian quartet of national parks. It is this rock flour that gives these lakes their spectacular colors.
The colors that we perceive with our eyes are a result of an object reflecting a particular wavelength of light, with all other wavelengths on the visible spectrum being absorbed. For example, behind my desk, I have an orange Whataburger number tag. This tag will absorb wavelengths that correspond with the colors red, yellow, green, blue, indigo, and violet, and it will reflect the wavelength for orange. When the reflected wavelength reaches our eyes, we perceive that color.
The rock flour disperses throughout the lake and is suspended in the water, most frequently near the lake’s surface. Water itself will absorb wavelengths for red, orange, and yellow, and the rock flour will absorb purple and some blue. What remain are green and blue light, which you see throughout the water in the mountains.
One special feature of the lakes and rivers pictured is that the color of the water will change depending on the time of year. In the summer months when the weather is warmer and the glaciers will melt more quickly, you will see more rock flour in the water, producing a stronger green color than you would see in the winter months.
The glaciers’ movement over tens of thousands of years produced the “U-shaped” valleys prominent throughout the Rocky Mountains and pictured at the top of the post in the view of Peyto Lake. Looking beyond the lake itself into the valley, you can see the gradual, rounded rock face stretching for many miles into the distance.
I’d highly recommend a summer trip to Banff and its adjacent national parks, if anything, for a break from Houston’s sweltering triple-digit heat index. It snowed in the mountains while we were there, but the temperature was more commonly in the 60’s and never exceeded 80 degrees! I’ve uploaded more photos from my trip to Flickr, and you can check out the waterfalls, wildflowers, and more here.
And if you’re curious to see some artifacts from this part of the world, come check out the Houston Museum of Natural Science! Several invertebrate fossil specimens from the world-famous Burgess Shale (in Yoho National Park, British Columbia) are on display in the Morian Hall of Paleontology at HMNS Hermann Park and in the Hall of Paleontology at HMNS Sugar Land. Or bring HMNS to you with Chevron Earth Science On Wheels! Old favorites like Know Your Rocks will cover erosion and the rock cycle, and new programs will be available beginning this fall.