In the arid wasteland of the Arizona desert, something enormous has appeared. It stretches out for miles, and scientists are pretty sure that it’s getting bigger. Yet this huge split in the earth isn’t a naturally occurring phenomena. No, the blame for it lays squarely on the shoulders of man.
Arizona is America’s sixth-largest state. It sits in the south of the country and shares a long border with Mexico. In terms of climate, while the north of the state is home to forests and endures heavy snow in the winter, the south is a different kettle of fish. And it’s there that the strange crack has appeared.
In the south of the state, the climate is considered desert. That means the area has long, hot summers and very mild winters. There are, though, actually three deserts in Arizona. The Chihuahuan Desert covers part of the southeast of the state, while the Mojave stretches into the west. The largest expanse of desert in Arizona is, however, the Sonoran.
And it’s in the Sonoran Desert that this enormous crack in the ground has appeared. The strange feature stretches for two miles in an area known as Pinal County, which is between Tucson and Casa Grande. But while the crack has been there for a couple of years, geologists are only now discovering the scope of it – thanks to the use of new technology.
Joseph Cook is a geologist who works with the Arizona Geological Survey (AZGS), and he was the first to spot the fissure. He didn’t make the find using traditional methods, mind you. Instead, Cook was at his computer when he discovered the opening in the ground. And that’s not the only technical innovation that the AZGS has used to investigate the crack.
You see, the first time Cook saw this new gap in the land, he was looking at images from Google Earth. That was back in December 2014. Cook then set out to map what he saw – but when he got there he realized that the imagery he’d seen was just the tip of the iceberg. The crack was much, much bigger.
Speaking to Live Science, Cook said, “I realized the fissure was much longer than what was apparent in the Google imagery, almost 2 miles long in total.” To begin with, then, the AZGS used GPS to look deeper into the fissure. But after that, they took another pass at it with some even more modern technology.
The AZGS actually decided to fly a drone over the length of the fissure. And the footage that the drone captured in fact marks the first occasion that the geologists have used such a gadget to find out more about fissures in Arizona. What’s more, the images that the remote-controlled device recorded have revealed some really interesting things.
For one, although the drone flight hasn’t revealed exactly how big the underground portion of the crack is, it has shown the full length of the new geological feature. It’s also provided some of the most dramatic images of the shifting landscape. And geologists now think they understand a good deal more about their newest find in the Arizona desert.
Perhaps the most interesting point about the fissure is that geologists fully expect it to keep growing. Now at its northernmost end, the crack is older. Here it’s not as deep, either, thanks in part to sediment having entered the crack and the walls of the little canyon collapsing in on themselves. This is by no means a uniform depression in the Arizona dirt, mind you.
You see, at its southern end the crack is 30 feet in depth in some places and reaches around 10 feet in width. Both ends of the gash are shallower than the biggest sections, too, though to the south the crack is becoming larger. It’s not just getting longer, either; it’s getting wider as time passes as well.
That said, while some parts of the fissure are enormous, others are only a few inches wide. Don’t let that fool you, however. According to Cook, most of the crack will have started out life as only some small gap in the surface. Moreover, it’s what’s underneath the crack that you should be worried about.
That’s because there are likely to be spaces underneath the ground – and the ground on top of them is prone to collapse. “These narrow sections sometimes have open voids underground, so collapse of the overlying material is possible – this is how the deep open portions of the fissure formed,” said Cook.
Hence, those smaller cracks are, in a way, far more dangerous than the more obvious, 10-foot-wide parts of the fissure. So although the crack is in the middle of the desert, anyone walking or driving along it without realizing could find the ground giving way beneath them. Indeed, it’s a huge danger to cattle that might be grazing nearby.
But that raises an important question: just what has caused the fissure to appear? And the answer, perhaps unfortunately, is far more mundane than you might imagine. Far from being the result of some tear in tectonic plates, say, or a potential volcanic eruption, the crack in Arizona is actually due to the actions of farmers.
The arid nature of the Arizona desert means that farmers need to look under the ground to get water for their crops and livestock. And once the water has been taken away, there’s nothing there to stop the ground above from subsiding. That in turn has created not just this crack, but plenty of others as well.
Which is to say that this is by no means the only fissure in the landscape of Arizona. In fact, it represents just over 1 percent of the cracks that the AZGS has mapped. And almost all of them can be traced back to the same source: groundwater being used for agricultural processes.
In all, the AZGS has recorded about 170 miles of cracks. These are found around the edges of what are known as subsidence zones; they’re also sometimes found where mountains reach the desert. So while this one fissure may be monumentally large, such features are by no means a rare occurrence in the desert.
Localized heavy rain, meanwhile, has led to the Arizona chasm getting even wider. This rainfall has resulted in more erosion in the already open areas of the crack. As well as that, the rain has made the dirt at the top of the opening collapse. And this in turn has exposed more of the underground fissure to the naked eye.
Furthermore, the crack that Cook found is destined to get much bigger, or at least become more visible. As the geologist put it, “I am sure the length of this fissure will increase over time, [that] we are only seeing the surface crack of what collapsed [and that] the underlying fissure is longer.” So while this crack certainly looks impressive, if there’s a larger cavity underneath, it may be best to stick to viewing the drone footage rather than venturing out to the desert of Pinal County for a closer inspection.