Molly again, just dropping by with some of my favorite photos from our big trip. Hoping they may give you an idea of the incredible diversity of materials and landscapes we encountered over the several weeks we spent on the road. Enjoy!
“It’s a twister! It’s a twister!”
Or at least it looked like one. In any event, the driving conditions during what was supposed to be our relatively short ride from Gunnison to La Junta, CO were certainly less than ideal. The wind slapped and banged at the truck in irregular bursts, and spooky tumbleweeds rolled across the road in the hundreds; the landscape churned with bits of grass and dead plants. Looking further up the highway, we saw a hazy, brown cloud that resembled a fire.
We soon realized that the “fire” was actually a rolling cloud of sand and dust formed by the fierce winds blowing out from the thunderstorm. Lucky for us, visibility was only slightly reduced. Here, take a look:
The area surrounding our sample site at the Alamosa/San Luis Valley contains the highest agricultural land in the United States. Here, elevations average around 7500 feet, with surrounding peaks over 14,000 feet. Local farmers specialize in “cool season crops” like potatoes, head lettuce, and barley. In fact, Coors beer (love it or leave it) is made exclusively from barley grown here in the Intermontane Plateaus of the Colorado Plateau Province.
Regional soils broadly consist of two types—the soils of alluvial fans and floodplains located at the valley floor (which we sampled), and those found on the hills and mountains. Had the weather permitted, with a little more digging around we would have expected to come across Colorado’s state soil, “Seitz soil,” which consists of very deep, well-drained, slowly permeable soils formed from igneous, sedimentary and volcanic alluvium. Seitz soils are abundant near the valley edges and on mountains, mainly in southwestern and central Colorado.
This was definitely one of the dustiest places we encountered; the valley regularly experiences periods of drought, with most precipitation occurring either during the winter months as snow, or during the short, summer monsoon season. However, much of the moisture from these precipitation events is lost through evaporation due to the region’s characteristically clear skies and dry, thin, high-elevation air. Thus, it comes as no surprise that the dry, heavily cultivated soils of the Intermontane Plateaus are easily influenced by the summer storm systems and strong winds.
After we arrived in La Junta, we discovered that several tornadoes had indeed touched down in northeast Colorado—hundreds of miles from where we’d been driving. Oh, well—we’re geochemists, not meteorologists.
P. S. Dust isn’t the only thing the La Junta wind transports (my sleeping bag exploded). Hopefully local birds and other critters have since put the down feather to good use.
We couldn’t have said it better than a local cowboy who stopped to give us his scientific opinion while we collected material from the cattle-spotted ranchland of northeastern Utah’s Green River Basin—“Well, I’ll tell ya, when it’s dusty, it’s dusty.” Way to hit the nail on the head, huh? Sure enough, we’ve spent the last three weeks shaking dust from our shoes, wiping it out of our eyes, blowing it from our noses. We’ve navigated many of the most arid places in the country, starting off just above sea level, eventually reaching elevations as great as 10,000 feet. Hard to believe we’re all done—for now, at least!
Along this dusty road, we’ve encountered a truly astonishing number of landscapes; each and every evening we pitched our tents, we did so in a totally different setting than the one in which we’d made breakfast. For instance, after we sampled the Green River Basin, we set up camp in Ashley National Forest near the Sheep Creek Geological Area, a place surrounded by enormous, rocky, red and yellow cliffs, thick with quaking aspen, ponderosa, juniper, and lodgepole pines. We watched pronghorns skip across distant ridges, and that night, made sure to watch out for bears, too.
Bright and early the next morning, we set out towards Moab. The drive from northern to southern Utah was full of beautiful, winding roads and spectacular colors, although Sarah and I weren’t really keen on the heat! Still, we were excited about visiting Arches and Canyonlands, as well as the fact that despite the long drive, we were able to cover three sample sites, and manage to snag the last camping spot in the whole park. A successful day indeed!
The formations of Canyonlands and Arches speak to the powerful force of wind in the evolution of landscapes. The salmon-colored Entrada sandstone, where most of the arches occur, was deposited around 200 million years ago. Over time, water and ice infiltrated the surface cracks of the sandstone layers, breaking off bits and pieces of rock. The holes formed from the cracking continued to be attacked by wind and water, forming arches. While many of these arches gave out long ago, the loose particles left behind carried away by the wind, the most resistant sandstone became the famous arches we see today.
We drove through thunderstorms, sunshine, across deserts and mountains, past rivers, lakes, and hot springs. Colors, plants, animals and temperatures—they all varied. These are just two of the amazing places we saw during our collection campaign.
Although we have collected our final sample and the Unimog is headed back up to Alaska, there are still many observations, photos, and stories left to share. Plus, our great American dust quest will resume later on in July when we travel by horse to the Upper Fremont glacier in Wyoming’s Wind River Range. Until then, keep on our your toes for my next update, with photos from our drive across tornado territory and a crazy Colorado dust storm.
Sarah, Charlie, and Molly here, reporting from Gunnison, CO. It’s our eighth day into GIGL’s dust collection quest in the great American West (add on six days on the road for S & C—they drove down to the Lower 48 from Anchorage to meet me in Spokane, WA), and already we’re gearing up to hit the tenth of our thirty proposed sample collection sites.
First thing’s first: you may be wondering why on earth a team of cold weather-loving folks like us has decided to devote an entire month to driving around the desert in the hot summer sun—and stranger yet, why we’ve got big, metal boxes packed with dirt and sand. Don’t worry, we’re already quite used to folks asking questions—just take a look at our ride:
The goal of our trip is easy enough to explain: we’ve set out to identify the major dust source areas of the western United States. Oftentimes we think of dust as the stuff that collects on our bookshelves and countertops when we get behind in our household chores, but in more arid parts of the country, say Oklahoma or southern California, you can see tiny bits of dust and sand all over the place—sweeping through fields along the freeway, collecting in piles in grocery store parking lots, or even blowing across your own backyard.
We all know that dust is small—sometimes so small you need a microscope to see it—so it may be hard at first to believe that dust plays such a big role in regional and global climate change. But just think: increased temperatures result in drier land conditions (think of how muddy your front yard can get in the rainy springtime, and how dry it becomes later on in the summer). With less moisture to hold soil particles together, the ground material becomes less consolidated and easier to blow away in the wind. The wind is a powerful mode of transport, and can carry tiny bits of sand and clay vast distances—even across continents—but no matter where the dust ends up, there remain a variety of important consequences. For starters, when windblown dust settles on land, it can supply nutrients to the local soil and plant life, and the same goes for dust settling in the ocean, or carried by rivers out to the ocean. Dust also darkens snow and ice surfaces, thereby decreasing Earth’s albedo, or it’s ability to reflect solar radiation.
Many studies have pointed towards increased dustiness on snow cover in the western US over the past two centuries, most likely due to land-use changes like agricultural practices and livestock grazing…but where exactly is all of that dust coming from? And why? Are the most prominent dust sources in areas where humans have made major changes to the landscape? At the end of the summer, we’ll haul our treasure chest full of dirt back to our lab at the University of Michigan and begin our geochemical analyses so that we may answer these important questions. In the meantime, we hope you’ll check back with us as we continue “getting the dirt” on arid regions throughout the American northwest, southwest, and Colorado Plateau. We’re excited to talk a bit more about what we’ve collected so far, and show you some of the incredible landscapes we’ve encountered. Until we next run into some WiFi, this is the GIGL dust team from our big, blue UNIMOG, going clear!