You’re familiar with dust devils. You might have even heard of water devils, too, but gravel devils? For people living in or near the Andes Mountains, it turns out this isn’t an unusual sight. Grab your scientific notebook and let’s get started. We’re going to learn more about this amazing phenomenon and what causes it from the ground up.
What Is a Gravel Devil?
Despite the name, a gravel devil isn’t necessarily always made up of gravel. Most contain crystallized gypsum and other minerals that shimmer in the light. This is what makes the gravel devil appear to sparkle in sunlight or when exposed to beams.
How Do Gravel Devils Form?
Gravel devils can form in a number of ways. The most common formation occurs over highly acidic pools of water near inactive volcanoes or lava flows. Gypsum crystals form from these areas as water evaporates, melding into crystalline structures that then get picked up by the wind. Like dust devils, wind conditions must be just right—changes in pressure and wind direction are almost always responsible.
Why Are Gravel Devils So Important?
Gravel devils are ecologically and archaeologically important for a few different reasons. Scientists who study them gain important knowledge about how different crystalline materials traveled around ancient Earth, and that can give us an intimate glimpse into a past world we’ll never see.
Studying gravel devils also reveals interesting information about which parts of Earth had the harshest winds many centuries ago. As some of the crystals can reach up to 10” or more in length, it could potentially teach us new information about how mineral deposits occur and how winds impact the surface of the Earth today. Through approximation, it might also help us to predict how high winds might further impact Earth long into the future.
After Travel: Interesting Outcomes
The process through which gypsum crystals travel (via dust devils) is interesting enough, but what happens once winds die down is also equally compelling.
Gravel devils spin up due to changes in the environment (mostly related to wind). The sheer force of those wind changes and the surrounding wind patterns dictate how far they will travel before they lose power. Some studies identify that gravel devils can potentially travel as far as 5 kilometers while carrying exceptionally large crystals, only dumping them on the ground when pressure or wind force finally changes.
Mountain air currents are just one of the reasons the Andes Mountains experience this phenomenon at a higher rate than other areas of the world.
Research shows that dust devils periodically dump crystals onto the ground in large mounds, creating cairns made entirely of crystals. Gypsum’s innate ability to meld with itself then kicks in. Over time, the crystals begin to warp and grow, combining with one another to create massive crystalline structures.
Science is incredibly interesting. Whether you’re a geologist yourself or working in a different field, SNCO wants to help you seek the supplies you need most to be effective and efficient. Contact us today at 800-537-3028 to ask about our range of scientific notebooks, cleanroom supplies, and research aids.