12 Fascinating Phenomena That Only Occur in Desert Lands

Everyone knows about dunes, right? They're what most people think about when they imagine a desert. They form when loose sand accumulates under just the right conditions. You need really dry sand, first of all, because moisture causes the grains to stick together. This is why dunes are most common in the driest climates on earth (but also, weirdly, in places like Michigan, thanks to some voodoo caused by the Great Lakes). You also need something to move the sand around, which is usually wind (but underwater dunes are also a thing). Lastly, you need obstacles for the sand to accumulate around (typically rocks and sparse vegetation). Ta da! Dunes!

But did you know that some dunes "sing"? It's true: climbing up or sliding down a dune under the right conditions can cause an avalanche that triggers a "100-decibel singing sound" caused by "a feedback loop of collisions." The face of a dune acts as a loudspeaker of sorts, amplifying the vibrations of the shifting and colliding sand. Researchers say you can feel the "song" in your whole body if the conditions are just right.

An oasis is not just a small speck in the desert with a few shade trees and a lake for weary travelers to lurch toward after they've emptied their canteens. Roughly 75 percent of the Sahara's population, for example, lives in oases, which vary widely in size. The popular image of an oasis as a desert paradise is pretty accurate: oases in the Sahara feature palm trees and food sources such as figs, peaches, wheat, and barely. The water at the hub of an oasis comes from natural springs or artesian wells and has to be managed carefully to ensure that crops are successful.

Finally: a pothole you don't want to fix! Desert potholes - also known as ephemeral pools - are naturally formed sandstone basins that support tiny ecosystems in the desert. The creatures that live in these things are fascinating: they have to endure extreme temperature fluctuations: "Surface temperatures vary from 140 degrees Fahrenheit in summer to below freezing in winter," according to the National Park Service. Many of these "pothole organisms" enter a state of "cryptobiosis" to tolerate the extreme conditions where they basically go into a "Sleep Mode," ceasing all metabolic processes (this means no reproduction and no development). When conditions improve, they simply snap out of it and go about their business.

These surreal desert pockmarks may look like something out of a Dr. Suess book, but they're definitely real - and definitely rare. They've only been found two places on the planet: the Namib Desert in South Africa and the Pilbara region in Western Australia. Researchers aren't entirely clear on how, exactly, the circles form, but the leading theory is that plants "organize" themselves into these crazy patterns "according to scarce water availability." The conditions have to be just right for the fairy circles to reveal themselves, and it seems like these two regions cast the right spell: despite being thousands and thousands of miles apart, Australian and African fairy circles are almost identical, with nearly the same repeating hexagonal shapes when viewed from above.

The one in the photograph above is a particularly extreme example, but still shaped by the same forces that produce all yardangs. Yardangs are vertical protrusions of bedrock or consolidated sediments shaped by wind abrasion and the removal of loose dust and sand (aka deflation). Typically, yardangs are shaped longer than they are wide relative to the constant direction of the wind that shaped them. They usually appear in groups called "fleets." Try saying it outloud in a sentence: "Let's take our engagement pictures next to that fleet of yardangs." Fun!

You've seen a haboob or two in your lifetime, whether you know it or not: haboobs are those menacing dust and sand storms that eventually strike in most movies set in the desert (Mad Max: Fury Road, for example, features a massive haboob). These storms occur when high winds lift loose grains into the air that then fall back to the ground and "eject" even more grains, causing a chain reaction. The dust and sand forms a dramatic wall - with a density sometimes likened to a storm of "dirty snow" - that can stretch thousands of feet high, causing low (or no) visibility. The high winds that accompany haboobs can even uproot trees and power lines.